Speedometer quit

[Prairie Dog]

It's going to be either the speed sensor on the Transmission ,or the ring gear sensor on the Rear axle housing... My monies are on the ring gear sensor.

Todd, that pic is interesting looking, any idea how the sensor was physically damaged?

Thanks,
Scotty

 

[cerberusiam]

Yesterday the speedo started working and simultaneously the outside temperature reading in the overhead consol started working.

Since this is an 03 check the ECU A & B plug for possible moisture contamination. All the sensor inputs are run thru the ECU then to the sub processors for display. There is a TSB for addressing intermittent problems with the ECU connectors.

 

[SDrake]

ECU ? Is that the engine control module, --- two plugs on the drivers side of the engine? My head is swimming right now. I thought I read somewhere "Do not unplug" these. Perhaps it was in some repair proceedure context that I need to understand.



I will see if I can find the TSB on this.



Thanks for the info on --- quote "All the sensor inputs are run thru the ECU then to the sub processors for display. " I'll bet that is coming from some hard won knowledge somewhere back when... "

 

[SDrake]

Did a search of the TSB's for 2003 year listed on TDR. could not find anything on the connector. Also I may be confusing terms. There are some ECM engine control module hits in the TSB's but no ECU. Maybe it was for a different year. At anyrate I would like to know what I can do about whatever connector this. Your mention of A & B connectors matches up with what is on ECM so I am thinking that is what you meant, --- hope to get my head straight one of these days.

 

[Prairie Dog]

I remember the issue too. It was way back in the beginning of the 3rd gens. Moisture was getting into those connectors and the dealers were replacing the harness (scary eh?). Thankfully, mine never had the problem.
As a side note, the manual says to disconnect the batteries before you unplug those connectors.

 

[cerberusiam]

Did a search of the TSB's for 2003 year listed on TDR. could not find anything on the connector. Also I may be confusing terms. There are some ECM engine control module hits in the TSB's but no ECU. Maybe it was for a different year. At anyrate I would like to know what I can do about whatever connector this. Your mention of A & B connectors matches up with what is on ECM so I am thinking that is what you meant, --- hope to get my head straight one of these days.

You got it, ECU and ECM are the same thing. There are 2 connectors on the ECU\ECM, front is A connector and rear is B connector.



The pugs did not seal correctly, moisture got in, corrosion ensued. You might try disconnecting them, cleaning with electrical contact cleaner and see if that helps.

 

[SDrake]

Thanks ever so much. I am going to disconnect the batteries before I do this. Just don't want to be extra cautious a out big booboos until I get to know this thing.



I did a search on the vin to see if all recalls had been done and all have. The recall for connectors involved the PCM I think. I am not aware of one on the ECM.



Any advise on how to make this thing less moisture sensitive would be welcome about now.



I posted a question about use of dialectric grease, and got pretty much a negative on that for this problem.

 

[cerberusiam]

I did a search on the vin to see if all recalls had been done and all have. The recall for connectors involved the PCM I think. I am not aware of one on the ECM.

Might be one on the PCM, definitely one on the ECU. Is it listed as a TSB, maybe not. It might be a different kind of bulletin.

 

[SDrake]

Might be one on the PCM, definitely one on the ECU. Is it listed as a TSB, maybe not. It might be a different kind of bulletin.

Thanks, I will keep looking for the information. maybe start a new post just on the connector.

 

[tim0]

any luck resolving your problem. I have an 03. 5 that on misty days the dash and overhead can quit working or the temperature display on the overhead displays "--". no luck at the dealers.

 

[SDrake]

any luck resolving your problem. I have an 03. 5 that on misty days the dash and overhead can quit working or the temperature display on the overhead displays "--". no luck at the dealers.

One piece at a time. I just received my rebuilt ABS controller that had the severely corroded 14 pin connector. It seemed to have something to do with the symptoms with the speedometer. The rear speed sensor comes straight into this connector before it goes out to the ECM.



I am still waiting on a repair kit for the harness end of the connector ordered over two weeks ago. So I can't report anything just yet. I am still concerned that there may be other problems because of the fact that the overhead console temp reading was coming and going at the same time the speedo would quit and revive. The temp sensor has nothing in comon with the ABS circuit that I know of. So keeping my fingers crossed. At any rate I hope to have my brake light and ABS light go out and yes the speedometer too. I will report immediately any new develoments.

 

[cerberusiam]

If a shorted fan will knock out the cluster gauges then its not to far a stretch to think the ABS controller would affect the OH. See what happens when you fix the known issue is all you can do. Good luck with it.

 

[SDrake]

If a shorted fan will knock out the cluster gauges then its not to far a stretch to think the ABS controller would affect the OH. See what happens when you fix the known issue is all you can do. Good luck with it.

I never cease fretting for quick answers but I have learned to do just that. Start fixin until everything works. Many times it was only after something started working that I could understand why somethng I did fixed it. The other way to play is go to the steeler ship and keep throwing money until you run out, and then sell the truck to pay off the bills.

 

[SDrake]

Apparently ABS controller solved

Installed the rebuilt ABS controller, rebuilt by ModuleMaster, and also replaced the 14 pin connector on the harness end using a kit PN found at the link supplied by mwilson in an earlier post. The speedometer and cruise work and the ABS and brake light are now out, --- finally.



The beauty about rebuilding the brake controller is that the rebuild uses higher grade components, says ModuleMaster, and you do not have to have your vin programmed in. No trip to the dealer. And of course $130 plus shipping beats heck out of cost of new controller. And it is guaranteed for 5 years.



I still have no clue why the overhead console temp reading is also working now.



Time will tell.



Again thanks to everyone for providing the information that guided my search and fix which kept me looking for an answer instead of giving up.