Engine/Transmission (1998.5 - 2002) CPS failure symptoms?

[SSolderitch]

I had some (5) codes last week and the the FSM stated (2) would throw a MIL, but they didn't. FYI: I have "gost codes" which throw a CEL in my car all the time, I reset or let the 5 cycle (cold to hot) reset, I can tell by how smooth the idle is if the oz sensor is working, reguardless of the light on or off. Now back to our trucks, Mine had me & the top guy at the dealership scratching out heads, he also called some cummins tech line, which had no answers... my problem was no prestart lift pump 1 sec run, wait light & no grid heaters (before run). I didn't even know when it stoped working, because of it was summer and now being fall with cool nights and mornings I was looking for the light. The solution was: I cleaned the pcm contacts which cleared (4) codes, including a p500, p1694, p1593 & p1687 which left only me with (1) code, I think the p1693 did not go away. I still had all my problems, so took it to the dealer. The diesel tech tested every sensor, wire, pin, battery voltage, etc. only to conclude my ECU was bad, everything external checked OK, next he wanted to swap the ECU before I spent money on a another one. The next day I got the call everything was fixed. With nothing to loose, he reflashed the ECU and got everything back. So what I am trying to say is that maybe a bad (dirty) connector or software glitch is causing you to think the CPS is bad (maybe it is bad, but), I was ready to drop $35-40 on a new IAT sensor, thinking that it doesn't know the real temp. That would have not fixed anything and I would be out the money & time. Why not unplug every (ECU,PCM,SENSOR) connector for some cleaning and dielectric grease, because it can't hurt. I hope you find the cause of your problem.

 

[T Peterson]

Learning "somtimes" is expensive...

First let me thank you all for knowledge and advise. I'll recap so you don't have re-read this thread. Throwing codes for CPS replaced CPS, no help, replaced ECM, no help,(ouch) decided it had to be the PCM, considering cost vs. dealer diagnosis I rolled the dice, replaced PCM, no go,(ouch again). Took it to a dealer I had not been to before in Temecula, CA, at first the tech was a little stumped and was going to bypass all the harnesses and hard wire all the way from CPS to ECM to PCM, then he calls me the next morning and wants to put a Cummins CPS in before he wired it. VOILA! So the first part I threw at it was no good. The first CPS was not Cummins. Only 3 good things have come from this, I found a tech (if needed again), my truck runs great, and maybe someone else can find this story useful. Oh ya, this lesson was only $1400 +-. :{



Thanks again, Tom

 

[JLandry]

Tom,



Glad you finally pinpointed the problem.



I think we've all learned a good lesson from your experience.



Best regards,



John L.