I'm at the Moab KOA...and need some CEL troubleshooting. (1 Viewer)

[Safado]

Here for the weekend and got a CEL on the way down. Pulled 4 codes

28...which I have memorized...#2 O2
83
84
85

The last 3 IIRC come in a set, but the search function doesn't seem to work on numbers. Anyone got theit FSM handy. Thanks In Advance.

 

[gbell210]

All Have to do with TCM Communication

83:
Trouble Area: ESA 1 circuit
Diagnosis: Open in ESA 1 circuit for 0.5 sec.,
after 0.5 sec. at idle or idle signal
faulty.

84:
Trouble Area: ESA 2 circuit
Diagnosis: Open in ESA 2 circuit for 0.5 sec.,
after 0.5 sec. at idle or idle signal
faulty.

85:
Trouble Area: ESA 3 circuit
Diagnosis: Open in ESA 3 circuit for 0.5 sec.,
after 0.5 sec. at idle or idle signal
faulty.


Honestly I don't know what that means, but thats whats in the FSM for my 94LC
Hope that helps.
-Gary

 

[Rich]

I have no first hand knowledge. I believe that Cdan has shared that this typically means that the ECM is now defective and needs to be replaced. Not good news.

 

[Safado]

hmmm....thanks so far... but too many achronyms for me to figure it out from here...anyone got that in English? Thanks

 

[Rich]

Your engine computer s*** the bed.

 

[gbell210]

TCM = Transmission Control Module
ESA = Electronic Spark Advance

AND this might help:
https://forum.ih8mud.com/showthread.php?t=57521&highlight=TCM+communication

Well it doesn't really "help" since the solution is $1000+ bought new sorry man ALthough, I guess you could have been driving around for a while with those 3 codes and #28 triggered the CEL this time

 

[cruiserdan]

Your engine computer s*** the bed.

yup.

You must have an early 93, pre May 93 production. Your ECM is likely an 89661-60170. You need to replace it with an 89661-60221.

You probably also need to replace the oxygen sensors.


D-

 

[Safado]

Thanks for the link Gary, and Dan...that thread really explained a lot. I remember once a month or so back getting a CEL and it going off a few minutes later...that must have been the ECM codes. Well, with that resolved I feel better about wheeling it tomorrow and Sat...now that I'm already here and have been driving with it for awhile. Thanks for the late night help. We'll be talking next week Dan...thanks

 

[fj803fe]

We are throwing around the idea of going out to moab this weekend. FreightDog, me, and Durango60, possibly Trapper50Cal in his 55.

If you're in need I can call the two local dealerships-I know they won't have the ECU, but...

Shoot any of us a PM and let us know...

 

[cruiserdan]

The vehicle is still driveable as it is. I would not operate it indefenitely like that but he should be ok for what he is doing at the moment.

 

[sleeoffroad]

Wait before you replace the computer. The computer is looking at the idle circuit. So you might think the problem is at the tranny, but more than likely the throttle position sensor is faulty or misadjusted and it is not telling the tcm that the truck is idling. Use the FSM and check and adjust the tps if needed.

Does your tranny still shift normally? If so the above is probably what is going on. Did you wash the motor or get mud in it?

 

[Safado]

Thanks for the suggestion Christo. These codes were more than likely a few months old, and I don't remember washing the engine compartment out, but there was a REALLY muddy trip a few months back...more mud on the exterior though...no puddles. I'll check the FSM out, as it sounds better than the $1500 alternative at the moment, and see how that plays out for now. The truck worked fine in Moab though...for the most part. Details later.

But one other thing I wanted to mention is that occasionally, when parked on steep inclines, it seems the Shifter doesn't align into Park like it should...I can't remove the key after turning the engine off. Sometimes just moving the shifter out and back in seem to fix it....this isn't related is it? Or is the Park Position Sensor somehow related? I think this however is related to some of the POs work. He dropped the transmission support bar by about half an inch to get rid of some of the deceleration vibrations...I think. When I put it back to stock, I had to re-adjust the tranny shifter and just don't think I have it quite in the sweet spot.

Anyway...thanks for your help everyone.

 

[IdahoDoug]

Safe,

The key issue would be unrelated. Sounds like the shifter is indeed not in the sweet spot. Also, on inclines it's a good idea to let the weight of the truck settle on the parking brake BEFORE putting it in Park, and then take the truck out of park BEFORE releasing the parking brake.

On your earlier ECU issue here's a couple more data points. I believe I have the old ECU and my check engine light comes on for a few minutes about 3 times a year and has done this since perhaps 60,000 miles. No issues or driveability problems. My brother in law's has also done this since around 100k, and at 150k it went to a solid on all the time. It is on to this day and he's had no issues either and the odometer is at 290,000 miles. So, carefully consider that ECU purchase if the truck is running fine.

DougM

 

[Safado]

Thanks Doug, more than likely it will only get replaced once I find a totaled late 93 or 94.