Electrical problems?

PimpinJonny · 12-21-2003, 06:20 AM

I am becoming very frustrated with my Service Engine Soon light on my 1996 SC1. It has been coming on and off for the past month or so. When connected to a scan tool, it told me the ERG pintle wasn't moving. So I removed the EGR and cleaned it several times, but only to have the light come back on and the same codes come up. So I cashed out $230 for a new EGR...and this STILL didn't fix anything. On top of this, recently my rear defogger and my chimes decided to quit on me. I have checked EVERY fuse in the car and they are all fine. I think it might be the actual chime unit on the driver side of the console, but I haven't checked that yet. Is there anything else anyone can recommend I do before I lose more money for somehting that will probably be a simple fix?

wolfman · 12-21-2003, 07:30 AM

This could be a difficult problem to chase down. (but then you know that already) The EGR valve on a 96' is essentially a step motor (a small electic motor that can open and close by command to various points and stay there) it functions kinda like a solenoid in many respects. Non-pintle movement "can" actually be two things:

1. The EGR pintle is actually NOT moving in responce to commands from the PCM. OR

2. The pintle IS indeed moving, but the PCM is not seeing the movement via the feedback connections going to the EGR valve.

Since you have replaced the EGR valve at this point with a new one, it is safe to assume that the valve itself is good. This would suggest that either:

A: The valve is not recieving the voltage commands from the EGR valve to open and or close.OR

B: Said movements ARE occuring and the PCM is not seeing them.

(Are you getting any "pinging" (spark knock) under modest acceleration ESP uphill?)

Both of these suggest that either the wirng to/from the EGR to the PCM are bad somewhere, the PCM itself is bad, or the power supply for the EGR valve is non-functional (also a part of the PCM)

Start by disconnecting the power connection to the EGR valve and using a continuity tester CONFIRM that all wires going to the PCM harness from/to the EGR valve are unbroken. That being the case, make SURE that the ECTS and it's connector (Engine Coolant Temp. Sensor) are good. REPLACE IT if it has not already been replaced and ensure it's connector is good/clean/uncorroded. DOUBLE check ALL the FUSES in BOTH fuse boxes (underhood and in car)

If all these things check out, I would first have someone with a scantool monitor the PCM/EGR valve on the running , driving car before condmening and replacing the PCM.

As far as your domelight/defroster issue goes (and again assuming you have checked all the fuses in the IN CAR FUSE BOX) your chime module is either loose or bad. It is a cigarette sized plastic box plugged into the BACK of the in car fuse box.

RiceRocket · 12-21-2003, 01:42 PM

A new PCV fixed my EGR error code. Try that first, its only $2 and easy to do. If that doesn't work....well then I feel bad for you.