Malibu ECM/ECU Questions

**LuangTom** · 07-19-2006, 09:54 PM

I drive a 2002 Chevy Malibu with 3.1L V-6, automatic, with a/c and cruise.
It surges/revs/chuggles at highway speeds by 100-300 rpm. It sometimes
does it enough to kick it out of cruise-control. We first addressed it as an
engine-problem. We changed fuel-injectors, MAF sensor and brake-switch.
It still did it. We re-flashed the ECM/ECU. No go.

So, we changed the torque-converter, torque-converter clutch, solenoid,
hydraulic-valve, shaft and seal. It still does it.

Next, we disconnected the cruise-control. It still does it. We re-flashed the
ECM/ECU again. It still does it. One tech feels it may be a glitch in the ECM/
ECU itself. I have a re-manufactured one on order. Any thoughts or suggestions as to what it could be or what to try next? This has been going
on since April......

**LuangTom** · 07-30-2006, 07:47 PM

I now have a re-man ECM/ECU in my possession. Two different avenues of advice have been received concerning it. One is to take it to the GM-dealer and have them re-flash and have a trustworthy auto-electric tech install it OR take
the unit to the dealer, have them install it and then re-flash it. Any suggestions?

**RedGTiVR6** · 07-31-2006, 04:57 PM

I'm curious as to why you would come to a CarPC forum and ask a question like this?

**LuangTom** · 07-31-2006, 06:42 PM

I was advised to by another gent. He said that maybe those with PC
experience would know the answers to my questions about the ECM/ECU.

**RedGTiVR6** · 07-31-2006, 07:04 PM

Since it's a 2002 it should be OBD-II - meaning you should be able to go to an auto parts store and have them scan it for codes that are being thrown with a scan tool. It should give you an idea about what's going on.

**LuangTom** · 07-31-2006, 07:51 PM

I have brought it to a dealer, an auto-tech and a "Precision AutoTune".
No luck in retrieving any codes. None have been read. No "service engine
soon", only the rev/surge/chuggle of 100 to 300 rpm at highway speeds.
I suspect it does not last long enough to code. Even when the tech was
on the road with a partner and reading his scanner, they did not get any
readable code, yet he said it did it often enough to kick the vehicle out
of cruise-control. Thus far, we are all stumped. I will go on the Chevrolet
Forum and see what I can find out there. Thanks for your input. I will not
be a bother here again. Ciao.