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Topic: Ford V-10 - Can't fix 0720 code

Posted By: fortytwo on 09/12/09 12:46am

2000 Ford F53 V-10
Two days after a transmission oil change in May of 08 the MH almost stalled leaving a fuel stop. Pulled over, stopped and restarted engine and performance was normal. Had Service Engine Soon light and ScanGuage had a 0720 code (output speed sensor). Over next 5 months and 9k miles happened 3 or 4 times.

Fall of 08 Ford Garage in Tampa determined it was the rear speed sensor and estimated a $400+ cost to replace. I passed.

This year same event happened more frequently, sometimes daily. Always same code. Couple of times the Overdrive "off" light would flash. Restart of engine, or reset of codes with ScanGuage always corrected. The near stalls would occur for a few seconds and then at about 40% throttle I would feel/hear a clunk in the rear end concurrent with a return of power to normal.

In mid August I had the speed sensor near/on the differential replaced. (sensor cost was $28 and about 30 minutes labor). Didn't solve the problem; returned to garage.
This time I was told there were 2 additional sensors on the Transmission (one on top, one on the side), that they had read a 0722 code (VSS-vehicle speed sensor) plus the 0720 code and that they thought the top one needed replacing (required removing supporting crossmember and lowering tranny couple of inches). 0720 code (but no 0722) now each time they tried to back out of garage.
Swapped the old sensor removed from top of tranny into side sensor location (they are identical). No change.

Downloaded troubleshooting guide for 0720 code. Next step was wiring trace. Nothing found, but now engine only firing on a few cylinders, and 18 stored codes, one of which points to an O-2 sensor. Found and replaced suspect wire to O-2 sensor located inside frame rail by right front wheel. No codes found during test drive. Operation normal.

Drove 1/2 mile to gas station for fuel. Leaving station temporary loss of power and 0720 code returns. No available bay in garage on return (Friday afternoon). I'm scheduled again Monday.

On trip back to nearby RV park I pulled a short 20% grade before campground and stopped for a minute (most events occur when the MH is at operating temp and has been stopped at a light, or waiting for traffic for a couple of minutes). Attempt to move forward resulted in another temp power loss, and the OD off light flashing. The OD off light stopped flashing after about 300 yards. Only code showing was again the 0720.

The sensors have all been changed, the wiring harness inspected, and all plugs cleaned and lubed. The Power Control Module has not been changed ($420 item, none are available in the Seattle area, and would take 4-5 days to get one). The service manager (appears very competent, has been honest and reasonably priced on other work I've had done, but it's been a big diesel rig shop for years), and all his "phone a friends" are out of logical ideas. Shop full of "greasy parts" mechanics; but no nerds with pocket protectors and I obviously have a computer related problem.

My analysis: never happens when in motion; always happens after a stop and attempting to move forward, or back into a site.
always happens at operating temp, never when cold - could be wire that has changed resistance due to long exposure to heat; not a tranny problem - have 15k miles since first occurance with no evidence of slippage or heat; PCM possible but engine operation is normal except for the 0720 events; 0720 is a speed sensor code, and only occurs at very low speeds it is probably a result of slightly different speed signals that breach a percentage of difference threshhold programmed in the PCM - always corrects itself when speed reaches 5-10 mph. Most probable cause a signal voltage difference caused by wire resistance change or damage. Don't know where to find anyone with a tool to measure/evaluate the signals.

Anyone encountered this?
Anyone know a source that may have a solution?
Tribal wisdom is solicited.


Wes
"A beach house isn't just real estate. It's a state of mind." Pole Sitter in Douglas Adams MOSTLY HARMLESS


Posted By: GPWayne on 09/12/09 01:16am

Look for a recall or service bulletin from Ford. I think it was a change to the grounds for the brain box. I'm surprised the ford shop did not catch onto that. Search the forum posts. I know it was covered here.
(I had a 2000 V-10 and had the problem but after resetting it never came back....I got lucky on that one...But never trusted the rig after that)

Good luck


Posted By: old guy on 09/12/09 01:17am

solution? sounds like it's time for a trade in. You must really love this truck to put up with so much trouble.


Posted By: heavyputer on 09/12/09 06:07am

old guy wrote:

solution? sounds like it's time for a trade in. You must really love this truck to put up with so much trouble.



"truck"????? The guy is driving a motorhome. "F53"


If at first you don't succeed, skydiving is not for you!!!


Posted By: SRT on 09/12/09 07:35am

GPWayne wrote:

Look for a recall or service bulletin from Ford. I think it was a change to the grounds for the brain box. I'm surprised the ford shop did not catch onto that. Search the forum posts. I know it was covered here.
(I had a 2000 V-10 and had the problem but after resetting it never came back....I got lucky on that one...But never trusted the rig after that)

Good luck


IIRC, there was a kit for an additional ground. Ours was done in Tuscon in March of 2005. BTW, replace the factory clamps on the coolant line that goes over the engine. We had a leak at high RPMs. Coolant would short out several plugs. The guy in Tuscon (south off I-19 to the west) also found and fixed that problem. Seems the heat of the engine would dry things out. The only evidence was a high water mark on the spark plug boots.


Posted By: skipnchar on 09/12/09 07:38am

What happens when you put the stock FORD tuner back in? I've seen a few of these kind of issues that could be corrected by returning to the stock chip.


2011 F-150 HD Ecoboost 3.5 V6. 2550 payload, 17,100 GCVWR -
2004 F-150 HD (Traded after 80,000 towing miles)
2007 Rockwood 8314SS 34' travel trailer

US Govt survey shows three out of four people make up 75% of the total population



Posted By: Lariat trucker on 09/12/09 07:51am

Did I miss something here? I didn't see where he had any aftermarket tuner or chip in use. I went back to the first post and the comment about the fluid change. Was this done via a flush system or was the pan dropped? I have dealt with the code on the V10 Super Duty and once it my fault I pinched a wire when replaceing a leaking pan gasket, the second was another shop pushed the pin out of the connector on the side of the case and it was causing an intermittent connection. The interesting thing was that both times, in my case, it tripped the ABS light also. The OP didn't indicate that the ABS light was lit.


Posted By: rockhillmanor on 09/12/09 08:14am

fortytwo wrote:

2000 Ford F53 V-10
Two days after a transmission oil change in May of 08 the MH almost stalled leaving a fuel stop...........This year same event happened more frequently, sometimes daily. Always same code. Couple of times the Overdrive "off" light would flash. ...... Attempt to move forward resulted in another temp power loss, and the OD off light flashing. The OD off light stopped flashing after about 300 yards.


I CAN tell you what the OD flashing and turning on is. This is directly related to the torque converter and sometimes rarely the wire inside the steering column which the wire is too short and needs to be replaced. Even if it is just the wire the OD button is tied into a myriad of computer output to the trans.

All I can tell you is mine flashed a few times, light came on (i.e. od off)once and then reset itself and the final time it came on doing 70 mph....you would not have wanted to hear all what that trans was screaming. Replaced torque converter. All for a stupid nylon valve that didn't seat properly within it that affects the vaccum/power.

Are you pulling your own codes?

And just another thought. I've had 2 things going on at once that stumped everyone. These V-10 are known to have fuel pump failures.

You mention the loss of power after warm. One of the big symtoms of fuel pump problems. Will run great when cold or whilewhile cruising but get it hot and stop and start and put a load on and the problem shows up. I made them check the fuel pump pressure and it was at 20 should have been at 40. You have to check it hot. The mechanics were SURE it was my brakes dragging.

So...loose wire in the column to OD AND fuel pump?

* This post was edited 09/12/09 08:29am by rockhillmanor *


"We must be willing to get rid of the life we've planned,
so as to have the life that is waiting for us".



Posted By: 2cyber71 on 09/12/09 09:40am

I'd get that checked at a very good Ford Truck Repair Center...and that's it!






Posted By: fortytwo on 09/12/09 02:27pm

Thanks to all for your suggestions.

Yes I like the MH. Looked to trade it last year - couldn't find anything that would be an improvement and made economic sense. 10 years, 110k miles, but it's also the devil I know.

Torque converter. Good thing to consider. My thoughts after analysis: I'm not getting power (RPM) to the engine. If it were the torque converter I would expect to hear the engine rev up but the MH not move. Have I got the analysis wrong?

Fuel pressure. Great thing to check. I'll have it done Monday. Suspect it will just be an item on the elimination check list as I have never lost power on a hill and full load ie. 3rd gear, 4200 rpm, load on ScanGuage 97%, throttle at above 50%.

Get it to a Good Ford Garage. I've considered that. Anyone have experience with Ford Truck expertise, and a full set of test equipment, near Seattle?

I'm using an upgraded ScanGuage II for reading codes. It doesn't return all though, only those it understands but does appear to be able to count the number.

PCM grounding may be the culprit. Will have it checked Monday. Don't remember ever having that show up. The folks that did the tranny oil change - Gator Ford, Tampa - (don't know if it was flush or drop pan but they promised me it was a complete change and I only gave them 17 quarts of synthetic) also did a Service Bulletin recall mod on the cruise control. Another item to check!

Think my analysis of wire resistance is wrong. Checked the extra removed speed sensor I now have. It appears to be simply a magnet in the end of a plastic cylinder about an inch long. It has two pins in a plug on the top. Looks like it works like a bicycle speedometer that simply counts revolutions of a magnet passing a pickup. If so it simply counts or it doesn't. If it didn't I would never get a good reading.

My current thought: all intelligence is in the PCM - pulse counting, comparing, deciding if 3 sensors agree, and then calculating the engine power requirement based on tranny and rear shaft input. Possibly the PCM is not flushing it's memory when the vehicle stops and is reading incorrect data at startup. Turning power off and restarting would correct that (and does correct the problem each time).

I did note a strange readout. When the Service Manager disconnected his big code reader after the last test drive and reconnected my ScanGuage I had a reading of 20-29 mph and a 34mpg readout on the ScanGuage. That corrected itself in the first 100 yards as I went to fuel up. I attributed that to the ScanGuage startup routine after reconnecting. Still think so as if the PCM thought I was already going 20 mph I should have had power issues on starting movement.

Still open for further input for my Monday Adventure.


Posted By: Hurricaner on 09/12/09 02:38pm

I'm sure you have tried this but just in case. Disconnect the battery for a few minutes so the computer does a hard reboot.

Sam


Sam & Kari
Hurricane, Utah


2004 34' Damon Challenger 315


Posted By: Lariat trucker on 09/12/09 03:56pm

Good idea Hurricaner I had forgot about the reset trick.


Posted By: MountainAir05 on 09/12/09 05:52pm

I had this OD light flashing and it turn out to be the wiring harness on the rear end and also the wiring harness on the transmission located on the RH side , the one that has the 12-18 wires on it next to the exhaust. Both were bad pins that had push out. The trans one also was push out and was touching other pins. Replace the plug on the transmission and the cable assy on the rear end. No OD light flashing or any other codes for the last several years. Good luck.


Posted By: jvann1 on 09/12/09 08:24pm

If you are in the Seattle area, I had work done at Bowen Scarff Ford in Kent, just south of Seattle. Was satisfied with work done, but it is done at Ford prices! If nothing else they can recommend someone, phone number is 800-577-1158.


2005 Ford F250
V-10 torqshift, tow command
Komfort trlr
"April" the attack cat!


Posted By: jheath on 09/27/09 10:24am

Had/have a similar problem with my 2000 Bounder 34T with 40,000 mmiles. OD light blinks and P0720 code is set. Connecting laptop to OBD terminal (Using Harrison R & D software) and putting RV in Drive showed various vehicle speed readings as RV was starting to move. One instance showed 79mpg and we were barely moving. I think the transmission tries to start off in 4th gear due to the incorrect speed readings. After looking at wire from shifter lever for pinches I started cleaning chassis ground points. Problem vanished a week ago after I serviced the ground point on the frame rail just ahead of the fuel pump. Have road tested it extensively (about 80 miles total) with a lot of stop and start on hills, with and without engine restart as well as about 60 miles of highway driving. Runs and shifts as it should now and am hoping that the electrical ground cleaning is the solution. I suspect that the (closed) TSB with the additional grounding harness was meant to overcome some of the issues with faulty chassis grounding issues.


2000 Bounder 34T
09 Ford Mustang & 87 Vanagon toads
2009 Ford F250
2010 Northstar TC800


Posted By: mhend12 on 09/18/09 07:00am

T18skyguy wrote:

Fortytwo, On year 2000 vehicles a common reason for the PO722 and 720 or VSS codes can frequently have nothing to do with the sensors being faulty.(I know that sounds crazy). A frequent cause is usually one or more bad or misfiring ignition coils that can backfeed through the PCM and cause partial or complete shutdown. VSS codes get set due to high load and no vehicle movement, like when you start out. The PCM thinks your rig is moving, but because the sensors don't correspond to the load, the PCM thinks the sensors are not reading and sets the codes. I would suspect one or more coils, especially those on the right rear and work forward. The tip about coolant leaking down and ruining the coils is right on, but on some vehicles condensate from the cold air conditioner lines can blow back and short the coils too, but that may not apply. Coils can be checked if they have the right tool.

Thats a good thing to check you do need to be monitoring spark to check. I have also found bad altnators doing the same thing, alt wearing and has low amperage and all of a sudden has a voltage spike will make the speed sensors go crazy.Happens because of startet wire from battery gets the spike and it is in the same harness as the speed sensor harness.You may have this problem with NO battery charging concerns. Have seen this quite a few times over the years


Mike and Alicia and Penny and Poppy the shelties
06 F350 CC Long bed 6.0
04 Laredo 29GS


Posted By: fortytwo on 09/18/09 03:37pm

Rambler: PCM cost = $475 plus shipping. Bellevue Ford now has one as I didn't need it.

FINAL UPDATE: The new PCM Ground Harness (7 wires with copper pins about one foot long, connected to a ring ground connector price $86) SEEMS to have solved the problem. Test drive with shop code device did not find any codes, nor did my ScanGuage II. Tried all the things that caused the incidents - could not produce it again.

This Ground Wiring fix applies to Jan 98 thru July 2000 build chassis. It was apparently closed several years ago after the problem MH's were fixed. Mine did not occur until 96k miles and 9 years. The new wire harness only deals with sensor grounds. It appears that the original harness had longer ground runs on some wires that caused them to transmit pick up stray signals and create errors. Therefore THE 0720 CODE CAN BE SET BY MANY OTHER FAULTS. It can actually be set by the ground wire of any of the speed sensors. My fix was relatively inexpensive. Finding the item to fix was VERY expensive, even with the shop discounting several hours of labor.

How does one get a summary of this problem into a "sticky" on the Ford Chassis list?


Posted By: wshrman on 09/18/09 04:33pm

fortytwo,
Just printed that off for my file,
Thanks


2009 Ford Flex
Belgian Sheepdogs, Blazer & Chayna



Posted By: Rambler on 09/22/09 12:38pm

fortytwo,

Check your PM's

Thanks
Rambler


Rambler
"Going Somewhere"
2001 Pace Arrow Vision 35R
2008 Jeep Liberty Limited
Brake Buddy
& Martin Guitar



Posted By: TropicalRV on 09/13/09 07:46am

If you had work done at Gator Ford, I would be highly suspect of them. Why on earth would you get any kind of fault reading after an oil change? These guys didn't do work on my coach that I paid them for, and then denied it. I would contact a Ford zone rep.


Paul
2001 Tropi-Cal 6350, Ford V-10, 310HP, 7.77 MPG
2002 Honda CRV 2WD, 27 MPG


Posted By: rhibray on 09/14/09 12:41pm

I have the same problem as you do, so am very interested in resolving this issue. I might add that the problem doesn't seem to crop up if you take the tranny out of overdrive, I ran several tests with overdrive off and on and the only time I got it to screw up was with the overdrive in the on position. I have several friends here that are also trying to help me fix the problem including a couple of transmission places. I did go with a suggestion to replace and lubricate up the back of new brake pads to no avail when I still thought it might be a brake problem. Lets keep in touch.


Posted By: don/lou on 09/14/09 01:36pm

Have you tried using it without the scan gauge plugged in??
Read a previous post where it was causing problems ??
Don't know if this will help but easy to try


Don & Louise
2000 Coachman Catalina 330 MSB /F53
2008 Impala- Remco Lube Pump , Blue OX tow bar & Brake Buddy
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Posted By: fortytwo on 09/15/09 01:12pm

Update: Waiting on overnight of PCM from East coast. None in stock in channel and had to get shipped from 3rd party mfgr.

Yesterday checked all grounds again and then jacked up rear end and ran with wheels off ground. Service Mgr was able to finally get a consistent failure code and flashing OD Off light. Somehow the PCM was not clearing the registers and the shops code reader was continuing to record an mph of 10-20mph after the rear wheels, and the tranny and drive shaft speed sensors zeroed. I had recorded a similar event on my ScanGuage but thought it was caused by the reconnecting routine. I had concluded that the PCM was probably the problem as all sensors were functioning correctly. The red herring distractor was the intermittent ocurrance of the problem (usually a bad contact or broken wire). Computers, which is what the PCM is, usually fail consistently. The only consistent items I could pin to each failure were normal operating temperature, at a complete stop for 30 seconds or more, or backing into a camping site -- but they didn't happen every time; started at 30-40 day intervals increasing to weekly, and more often over the last 16 months and becoming several times a day this last month.

My best guess is electronics in the PCM changed resistance with temperature over time. The only mystery is why the PCM only malfunctioned at a stop. Only a guess, but probably due to a percentage calculation that was only out of range with very low numbers.

These newfangled motors make one yearn for the old days of 4 barrel carbs, mechanical distributors, and replaceable points; especially when you get the troubleshooting bill.


Posted By: Rambler on 09/15/09 01:58pm

Fortytwo,

Let us know how everything shakes out when all done.

Thanks for all the good input from everyone. I have had this reading at times.


Posted By: Don36G on 09/15/09 04:26pm

DON'T INSTALL THAT COMPUTER, untill you check this.
Found this info from a couple of service shops that fixed the same problem codes P0720 and P0722
This is a F53 Motor home Chassis. Overdrive (OD) Light will flash and the transmission will downshift all by itself. Sets codes P0503, P0720 and P0722. When stopped, the Vehicle Speed Sensor (VSS) is still showing readings.
Tests/Procedures:
1. Perform a voltage drop test of the PCM grounds using a Digital Volt Ohmmeter (DVOM) or lab scope while revving the engine up and down to determine if the grounds are solid or not.
PCM ground pins include pins 3, 23, 24, 25, 51, 76, 77, 103 which are all Black/White (BK/WH) wires except pin 25 which is a Light Blue/Yellow (LB/YE) wire.

2. If a signal is seen on the ground circuits of the PCM connection, install a jumper harness per TSB 02-11-3 to improve the PCM grounds.


05 Winnebago Journey 36G


Posted By: fortytwo on 09/15/09 08:47pm

Don36B: THANKS! I knew someone had encountered this problem and a solution to it.

The TSB you reference has been closed and the part no longer available according to info my Service Manager got from the Seattle Ford folks. Too late to get Tech Support today but we'll be contacting them first thing tomorrow looking for a substitute for the wiring harness in that TSB. We (Service Manager & I) searched for this info; probably couldn't find it because Ford closed the TSB. We'll certainly get a harness like that constructed and installed before we install the new PCM. It has been shipped, but hasn't arrived yet.

The absence of a PCM in the supply chain also raises a red flag for me. Is it because they rarely fail, or because they fail so often they are out of stock?

Sort of raises the issue of the need for a complete schematic and function document on the PCM. Does anyone know if a "black box test unit" that can evaluate the PCM exists?


Posted By: cjalphonso on 09/16/09 03:49pm

I just wanted to let you know I recently had a PCM failure on my 2000 F53. Totally different problem, mine would run beautifully for an unforeseen amount of time, 50 miles maybe, then just die. Like you turned the key off. Then it might run for 5 minutes, didn't matter if hot or cold. It was in a shop for 6 weeks, Long story, but after all ground checking we finally determined it to be the PCM.

When we ordered the PCM, I found out that they manufacture them on an as needed basis and no-one stocks them. When an order is placed, they build several at a time. You may recieve one from my order So far everything works well on mine. I've noticed more and more of this PCM failure. I must say, I'm still scared its going to leave me somewhere, time will tell. Good luck with yours.






Posted By: Rambler on 09/16/09 04:01pm

Fortytwo,
Have you found out anything to give us an update yet?
Just curious? What is the cost of a PCM?

Thanks


Posted By: fortytwo on 09/17/09 05:26pm

Update:
Finally found PCM wiring harness in Las Vegas yesterday. Overnighted to Bellevue Ford, but my garage is in North Bend, 34 miles West so it didn't get delivered here until late today. Install tomorrow.
Replacement PCM reported shipped, expedited service, for which I paid $35 extra, two days ago. No confirmation of arrival yet.
Maybe get operational tomorrow.


Posted By: T18skyguy on 09/17/09 09:48pm

Fortytwo, On year 2000 vehicles a common reason for the PO722 and 720 or VSS codes can frequently have nothing to do with the sensors being faulty.(I know that sounds crazy). A frequent cause is usually one or more bad or misfiring ignition coils that can backfeed through the PCM and cause partial or complete shutdown. VSS codes get set due to high load and no vehicle movement, like when you start out. The PCM thinks your rig is moving, but because the sensors don't correspond to the load, the PCM thinks the sensors are not reading and sets the codes. I would suspect one or more coils, especially those on the right rear and work forward. The tip about coolant leaking down and ruining the coils is right on, but on some vehicles condensate from the cold air conditioner lines can blow back and short the coils too, but that may not apply. Coils can be checked if they have the right tool.


Retired Anesthetist. Pilot with mechanic/inspection ratings.1996 Jayco C 22 foot with 460/Banks Powerpak/Bilsteins.Wife and daughter. Two cats which control my life. 1975 Ford F-250, 84 Coupe Deville, Thorp T18, tons of tools and tons of junk.


Posted By: jimwo1 on 09/07/10 02:48pm

Does anyone know where to get the harness (1C3Z-13N850-AA) for this fix? I am having the shift problem and when I am stopped my scangage shows 10-15mph. I called ford and they said the harness is no longer available.

Jim


Posted By: BobBosick on 09/09/10 04:21pm

Jim
Did you ever find the wiring harness? My RV is having the same issue, but the local Ford dealer told the the part was obsolete. He said that Ford will stop making a part if sales are not sufficient to make a profit. I told him that I thought they were required to make parts available for 10 years, but he said that was an urban legend. It seems like more of these chassis are failing as they get older. Only the really bad ones failed early on. I have a feeling that more and more people are going to have this problem as the RVs get older.


Posted By: gatorcq on 09/09/10 06:08pm

Here is the deal. If the shop states it is one thing, and that does NOT fix the problem. They should re-install your original part and not charge you. You get an estimate from the shop to fix it. If they cannot and they are wrong, they should own up to the fact it is beyond their scope and refund / replace the $$$$,


Dale & Susan
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Posted By: SRT on 09/09/10 06:23pm

Whoops, already posted previously.


Posted By: jimwo1 on 09/09/10 08:31pm

Bob,
I have not located the part. I am thinking of making my own harness if I can find the pins. From what I am reading on the TSB another solution might be to move the 7 pins to another ground. In theory I should be able to cut the wires just below the the connector on the existing pins and solder them together then move them to a separate ground.

Jim


Posted By: BobBosick on 09/10/10 12:01pm

Jim
I'm thinking about doing the same thing. The only reason I hesitated is because the PCM is in an uncomfortable position unless I remove the drivers seat and even then I know it's going to be a pain. That's why I wanted to pay someone to do it. The problem is I can't be sure they'll do a good job and since they charge by the hour I'll be paying them to learn how to do it.
I spoke with Ford RV help line who confirmed that the harness is no longer available, but they claimed that any ford dealers parts department would be able to get the pins by looking at the TSB and the part number for the PCM connector. He also claimed that with that information, they would be able to make the harness at the dealership. I've always had a problem getting a Ford dealer to work on the RV, so I'm skeptical about that. I still think that a lot of these chassis will start to fail as they get older.


Posted By: jheath on 09/11/10 07:59am

Update to my post of 09/27/09......
After servicing chassis ground point(s) as described (and sitting for the winter) the RV ran with no problems on several trips this summer. We accumulated about 4000 miles without any trouble codes. The TSB was obviously meant to eliminate grounding issues, however it appears that correctly servicing the existing grounding points can accomplish the same end.


Posted By: BobBosick on 09/11/10 07:35pm

how did you identify the existing grounding points? It looks like there should be 7 of them. Can you provide the locations on your RV or explain how you fond them?


Posted By: BobBosick on 09/14/10 04:26pm

OK, I just finished disconnecting the PCM connector under the dash and it looks like a very easy fix even without the Ford harness (maybe easier since I don't have to remove the pins from the connector). Using the TCB as a guide, I removed the 2 existing ground eyelets from the firewall and the black cover from the PCM connector. The TCB says to remove the red cover, but that isn't necessary if you're not going to remove the pins. If you look at the diagram of the front of the connector and then identify the actual wires on the back that correspond to the grounds that are being replaced, you can see that they are all black with a thin white strip. I was expecting the grounds to be black, so all the better. It looks like a very easy fix just to cut the wires leaving a 2 inch tail to solder a new wire lead that can be attached to the firewall just like the harness in the TCB. I'm going to solder 7 individual leads (with small individual shrink tube for insulation)rather than one, although that would also probably work. Using individual wires wile make checking continuity between the new eyelet at the end of the new lead and the proper connector pin shown on the TCB easier (Just as a cross check). So tomorrow I will buy some copper wire and eyelets and finish the project. I really didn't want to climb under the RV and hunt for all those ground points.


Posted By: BobBosick on 09/16/10 07:02pm

I completed the TSB myself using the procedure I described above. All 7 of the leads were black with a white stripe. I cut leads below the connector rather than removing the clips from the connector which was a lot easier. I soldered about a foot of 18 gauge black wire to the end of each lead and covered each joint with shrink tubing to insulate them (just in case). I then soldered a single eyelet to the end of the new homemade 7 wire harness and attached the eyelet just as described in the TSB. The RV started right up, but I wont be able to take for a test drive for 2 weeks. So I wont know if this cured the problem for a while.


Posted By: jimwo1 on 09/16/10 09:03pm

Bob,

Thanks for being the test subject. I have not had time to try the fix but it sounds like it will work. You would know right away if you had a Scangauge. When mine is in park it shows me going about 10-15mph. I will hopefully have time in the next few days to get this done and report back.

Jim


Posted By: LVJ58 on 09/16/10 10:27pm

This may be of interest:

http://www.ford-trucks.com/tsb/fulltext/show_article.php?tsb=02-11-3


Jim & Sherry Seward
Las Vegas, NV
2000 Residency 3790 V-10 w/tags & Banks System
2003 Suzuki XL/7 toad


Posted By: jimwo1 on 10/20/10 09:46am

Bob,
Did you get a chance to test drive the rig and see if the fix worked?

Jim


Posted By: jheath on 10/20/10 10:58am

Posted: 09/11/10 07:35pm Link | Quote | Print | Notify Moderator

--------------------------------------------------------------------------------
"how did you identify the existing grounding points? It looks like there should be 7 of them. Can you provide the locations on your RV or explain how you fond them?"

Belated response to Bob B.'s query quoted above.

I started at the wire coming from the sensor atop the transmission and worked forward until I found an obvious ground point. The culprit was located a couple of feet ahead of the fuel pump on the driver's side frame rail. This location is exposed to spray and debris thrown up from the left front wheel. I removed all connected wiring and cleaned (Dremel tool with wire brush) all connectors and the area on the frame where all were attached. After replacing the nut and bolt I spray coated the area with Rust-O-Leum paint. This process appeared to correct the issue. At least I have had no recurrances and have taken the RV on trips to Wisconsin and the Oregon coast as well as several local trips here in Montana.
Your fix using the defunct TSB information is a probably just as good as rolling around under the thing and cleaning ground points. And probably a lot easier on your clothes! I'll be interested too in the results of your efforts so please do post them here as this problem promises to become a common one as our vintage F53 chassis RV's continue to age.


Posted By: BobBosick on 10/29/10 11:24pm

This may be a bit premature, but as of today, I have driven 166 miles without a problem and I've tried to be extra hard on the rig (accelerating quickly at stop lights and taking it up to 70 MPH on the freeway). I've been at the California State Park in San Clemente for about 3 weeks and still have 4 days until my return trip. I'm not sure that 166 miles is a good test, but by the time I get home, I should have over 300 miles on the rig and hopefully the overdrive light will continue to stay off. Anyway, so far so good, no overdrive lights and no weird shifting.


Posted By: BobBosick on 11/08/10 11:40pm

OK, I'm back from my trip and have had no problems for the last 300 miles. I hate to think of all the money some people may be paying to get to the bottom of this problem. The only reason I decided to tackle this myself was because it was so difficult to find a Ford dealer willing to work on it. Then I found out that Ford no longer made the harness (which turned out to be a good thing - the repair was easier without it). Several RV repair shops that were recommended by the Ford Customer Care Center wanted up front diagnostic fees of over $500 even though I just wanted them to do the work on the TSB. The only dealer that agreed to do the work backed out when they discovered the harness was no longer available. I did initially replace each of the 3 speed sensors before I discovered there was a TSB on the shifting problem. So I did end up spending about $70 on unnecessary parts.


Posted By: roam1 on 11/09/10 05:34am

BobBosick wrote:

OK, I'm back from my trip and have had no problems for the last 300 miles. I hate to think of all the money some people may be paying to get to the bottom of this problem. The only reason I decided to tackle this myself was because it was so difficult to find a Ford dealer willing to work on it. Then I found out that Ford no longer made the harness (which turned out to be a good thing - the repair was easier without it). Several RV repair shops that were recommended by the Ford Customer Care Center wanted up front diagnostic fees of over $500 even though I just wanted them to do the work on the TSB. The only dealer that agreed to do the work backed out when they discovered the harness was no longer available. I did initially replace each of the 3 speed sensors before I discovered there was a TSB on the shifting problem. So I did end up spending about $70 on unnecessary parts.


Bob,
Great job and thanks for informing.
The only thing I would add is to use a tinned wire for marine use if you can (like Ancor from West Marine). I've had similar issues in the marine environment where corrosion and poor connections are common. Copper wire will be corroded easily and tinned copper usually outperforms! Your issue may have been the pin connectors or the pin/wire crimp combo, don't know, it's a inexpensive suggestion!


Posted By: jimwo1 on 12/28/10 07:45pm

All,

I did the same fix as Bob and am happy to report that after about 400 miles of driving the coach has never shifted better.

Jim


Posted By: BobBosick on 01/06/11 07:50pm

Well,
I've gone another 300 miles with no problems. I still look at OD light out of habit, but just like Jim, the coach shifts like new. I hope that anyone with transmission problems takes the time to do research on the internet or it could cost them a bundle. I'm disappointed in Ford for the lack of support they provided throughout the whole process. Dealerships should at least look at problems even if they don't have the facilities to do the repair. An RV is just a truck, after all. They could provide an initial diagnosis and arrange to transfer to the closest Ford facility that can do the repair. That would take a lot of stress out of breakdowns on the road. I had the differential on my coach go out at 45,000 miles in Palm Springs a few years ago, but the local Ford dealer would not take it. The RV was only 5 years old at the time, so I thought it might be covered under warranty (it was not - it ends at 36,000 miles). If a Ford dealer did the repair and the problem was caused by an assembly defect, I assumed it wouldn't cost me anything. Or, they might offer me a goodwill discount. Instead, the Ford dealer referred me to a local repair shop, but they were to busy to do it. I finally drove it grinding and chunking to a another repair shop that that repair shop recommended. The repair cost $2,000 and the problem turned out to caused by the drive shaft bearing not being seated properly when it was pressed into the rear end housing at the factory in Mexico. Since it was not repaired by a Ford dealer, Ford will never know about the problem and I suspect they don't want to know anyway so they don't have to offer any discounts. I think my problem was unique, but the whole incident and my experience with the shifting problem has left me with a poor impression of Ford generally. At Ford quality may be job one, but job two is avoiding responsibility for known problems even when they're acknowledged by the company.


Posted By: trailmeisterjoe on 01/07/11 10:27pm

If in the Seattle area, bring the MH to chucks rv in everett. i had a similar issue years ago with my'99 f53 and they sorted it out. had to replace the trans pcm and groung it better if i recall. i too thought it was the speed sensor and tried 2 different ones ( 10 minute do it yourself job) but was wrong.

Joe


'99 rexhall rexair with 2 slides 32 ft


Posted By: whitebb on 10/02/09 01:42pm

I hope you get a good PCM as I had that same code problem and replaced rear end sensors 2 times ad first after market one was failing, was at the repair shop expense. Finally went to Mac Haik ford truck shop in Houston and codes were pointing all over the spectrium,checked wiring issues and fixed all codes except the code now for PCM. Ford shipped 3 units and 2 weeks later found a good one. Good luck, and GoodSam maintance ins paid all except deductable. Good luck.


Posted By: wny_pat on 10/02/09 02:37pm

T18skyguy wrote:

but on some vehicles condensate from the cold air conditioner lines can blow back and short the coils too, but that may not apply.
My son had that with his old Ford pickup. The AC line ran right over one of the coils and condensation would drip on the coil. Ford could not figure out what to do except replace the coil pac. My son fixed it with a piece of foam rubber insulation like you put on a water pipes to keep them from freezing, about 6 inches worth. Never had a problem after that.


“All journeys have secret destinations of which the traveler is unaware.”


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