Engine/Transmission (1998.5 - 2002) Erratic idle & inability to reach road speed

[Gordon Maney]

I was driving home tonight when the engine speed fluctuated several times, then would rev up, slow down, and sometimes do a rapid throttle blipping kind of thing.

I found a throttle position where I could travel at 25 mph in 4th gear [NV5600]. If I took my foot off of it to turn a corner it went into the rapid fire, throttle blipping mode.

After arriving at home, thankfully, some 16 miles later, I got these codes:

PCU
P1693

ECU
P0238
P0121
P0563
P0113
P0343
P0606
P1475

I am surprised there are so many codes. One of them is for the throttle position sensor, and the way it acted, that seems plausible.

Given the experience of the group, what are your thoughts?

Thank you.

 

[JLandry]

Gordon,



These codes taken together seem to point toward an internal failure of the ECM... possibly a runaway condition of the 5 volt power supply for the sensors.



If it'll start and run OK, then make sure the charging system and battery voltage are within the normal range of 12-14 volts. If that checks out, then it sure sounds like the ECM may be toast, especially because of that P0606 TDC: ECM Failure.



Good luck,



John L.

 

[Gordon Maney]

That is sad news. This is the third ECM this truck has had. The original, then a recon unit provided by Cummins, and now this one, which is a so called reconditioned unit, reconditioned by what I concluded during my dealings with them as a totally disreputable company.

I was hoping I would learn it was the throttle position sensor. :-(

This power supply you mention is part of the ECM?

 

[JLandry]

Did the other two ECM's fail with the same symptoms you're getting now?



John L.

 

[Gordon Maney]

No. The first failures, for a while, it would essentially just idle, and then did not start. None of this erratic speed changing and throttle blipping effect.

 

[cerberusiam]

That is sad news. This is the third ECM this truck has had. The original, then a recon unit provided by Cummins, and now this one, which is a so called reconditioned unit, reconditioned by what I concluded during my dealings with them as a totally disreputable company.

Unfortunately, your experience is quite common. Sometimes 3 or 4 or even more swaps to get a recon ECM that works correctly.



I know exactly what you mean though. $2k later on my sons 01 and a Cummins reman ECM to fix it because the temps started dropping below 40 degrees regularly and the truck was undriveable just like you describe.

 

[Gordon Maney]

On one occasion I did go to the Cummins dealer, but I don't think I would again, as they don't have test equipment that can evaluate the PCM. They can only diagnose the ECM. They had my truck for three weeks, largely because they put on a bad recon unit and then took it off, thinking it was not the ECM.

I am inclined to go to the dealer. What is Chrysler's source for recon ECM's? Apparently new ones are no longer available. That seems insane to me, given the age of the truck and the quantities that were produced.

 

[cerberusiam]

Not sure the dealer source is that great either. The incidents of multiple units needed to fix a problem are from dealers.

 

[RobertBradford]

Another source for an ECM is Go ECM Diesel, they have a page on the internet. I had to replace mine last summer and not only do they provide the part but also program them. The thruck runs great now, they did good work.



WHAT EVERY YOU DO DO NOT GO TO ECM OUTLET!!! out of Michigan. They will rip you off. They took my unit and that's the last I heard of them so when I went to Go ECM dielsel I lost the core charge.



Anyway good luck. It's ashame that when the ECM goes getting the truck fix becomes a big hassel.

 

[Gordon Maney]

Not sure the dealer source is that great either. The incidents of multiple units needed to fix a problem are from dealers.

That might not be so bad IF the subsequent failure was in the warranty period. They define that as 1 year or 12,000 miles.

 

[Road Dog]

It is bad if you're 500km from home and deep in the bush. Some people like their old 12V because there's no electronics to leave you stranded. You don't even need a battery once it's running.

 

[Gordon Maney]

The dealer wanted to replace the ECM, the throttle position sensor, and the camshaft position sensor. The total cost would be $3. 143. Of that, $805 was for the TPS.

My concern is they are wanting to sell me anything referenced by set codes. I struggle to believe all three are bad, and have the impression from reading other threads that one component going bad, and certainly the computer, can cause other parts to not work correctly, thereby setting additional codes.

If the cam sensor is the one covered by the VP44, then I replaced that when I replaced the pump, as it was suggested to me that is the time to do it.

I have agreed to have the ECM replaced at a cost of just over $1,900. They are charging me a core charge on the ECM because I don't have an original ECM marked with an OEM part number. Another reason, in retrospect, to not have gone with the so-called recon unit from the aftermarket [scam artists] ECM remanufacturer.

I see where you can buy the important internals of the TPS for about $200, which would be a far cry from the $805. The dealer onlyl wanted $165 to replace the cam sensor, and that was parts and labor. So it can't be too expensive of a part, and not too difficult to replace.

 

[cerberusiam]

I see where you can buy the important internals of the TPS for about $200, which would be a far cry from the $805. The dealer onlyl wanted $165 to replace the cam sensor, and that was parts and labor. So it can't be too expensive of a part, and not too difficult to replace.

I have no idea what they are talking about for $805. The OE APPS shoild be around $400-450 and that is all that needs replaced if it is the APPS. A Timbo APPS is $165, if you need one.



I know for a fact a bad ECU will throw APPS errors, PCM bus communication errors, and FPCM communication errors. Quite probable it could also throw cam sensor errors.



Replace the ECM and go from there.

 

[RobertBradford]

I wouldn't replacing anything else until the ecm is installed and tested. It sounds like the old "replace everything because I'm not sure and want to make money" deal. I think one of the most important thing you can do is clean and di-electric every connector in the system and don't forget the grounds!! When I did my ecm I went throught the entire truck and cleaned every connector andd greased them. Did it help... I don't know but it doesn't do any harm. Computers like clean electricity.

 

[Gordon Maney]

It seems to run very well now with just the ECM replaced.