QuestionQUESTION: THIS HAS BEEN A LONG ONGOING ELECTRICAL ISSUE:
(please, a brief history to support the issue and the question)
1999 savanna 2500 5.0L (Auto-gas)140K
I was able to finally track a random stalling and no-start problem down to a security and pass lock issue.
I "retaught" the PCM the security code following some online directions I found...I did the "learn" process 3 times then the "security" light went out and engine started no problems.
Before I did the above, "they" (local dealer then an independent cert. mech) over time changed a crank senor,cam sensor, battery, full tune up, fuel pump and 15 other expensive parts that were NEVER needed!!!
"They" also insisted the problem was the PMC.
The PCM was visibly aged but never proved by DTS codes to be the issue, it was the pass-lock!
Anyway, I found a "spare pcm" online (very inexpensive) so I changed that as well, just to cover all possible bases.
($750 from the dealer...$85 from a very nice guy I found online...)
I installed the "new" $85 pcm and it worked fine, yes...it was programmed to the vin#.
Currently everything is running fine and the van has been dependable...it starts all the time...it has not stalled.
The 2 remaining issues that were never corrected with any of the above work is an inaccurate gas gauge (it spikes or pegs out at engine start and is inaccurate on 1/4 tank and lower)
If you look at the needle closely while the engine is running, it looks like it is vibrating @100Hz!!)
Note: the sending unit was changed with the fuel pump 2 weeks ago.
Also, the speedometer is "jumpy" from around 0 mph to 20 then responds fine above that speed.. When decelerating, it is fine until approx 20 then jumpy back down to 0.
Are these functions of the BCM or in anyway connected electronically?
Is the BCM related to the fuel gauge at all?
Specifically, where is the BCM on this van?
Any insight to the speedometer and fuel gage is most appreciate.
Thanking you in advance.
Dave Y
wiring
ANSWER: From the research I have done I cannot see anywhere in the wiring for the trans or the fuel system where the BCM has any input or control. I did find in the attach wiring schematic a fuel sender buffer module, which if faulty could cause the gauge issues you are having. You stated a new pump was installed, often times you can get a pump or the entire pump assembly with the level sensor. IF you just got a pump there is a chance the level sensor is faulty and should have been replaced due to miles and time when the pump was serviced. As for the speedo, you may have a faulty VSS vehicle speed sensor, as I do not see that the BCM drives or monitors that system either. It is controlled by a VCM vehicle control module. I know you stated that the PCM was replaced, we have done many PCM's on those vans and often times its not necessarily the PCM but the wiring that is faulty, specifically in the connector, lots of corrosion and rot. So long as the wiring at the connector appears to be clean, I would verify that the fuel sender buffer is functioning and the vcm is functioning, if so you may just have a faulty cluster which we have also seen before, best of luck.
---------- FOLLOW-UP ----------
QUESTION: Talk about Karma: I shot myself in the foot by posting that the problem was solved!!! 2 days later, van died again.
The van will start when left alone for 1 to 24 hours and will eventually start without ANYTHING being done...literally, other than opening the door and cranking the engine, eventually it will start for a short time without anything being altered. Sometimes it will die within 10 minutes or 2 hours or longer.
Question: the original problem remains: the van cranks, 65# fuel on the rail but no spark at the wires.
All the above info from the first posting still relevant...new pmc, battery, wires, coil, cap, rotor, crank sens, cam sens, ing coil/mod, fuses %26 various relays....
Mechanically (specifically, majority of likely problematic electrical components) have been changed.
Again, the overall problem is an intermittent start / stall.
I've since learned it was not passlock related as that would disable fuel not spark!
Also, no codes are showing.
Could it be ignition related, passlock, BCM or does it need a dealer complete reprogramming?
Any insight...please.
Thank you in advance.
Dave
Answerin hindsight i should have asked when you had the PCm replaced was it properly programmed? meaning the VIN for your truck learned to the vehicle? if not that could in fact be the main issue, other than that it could have a ignition switch that is faulty, with a scan tool connected when the vehicle is in a failed state you could monitor the voltages at the ignition switch
