Possible electrical or computer problem (2003 Grand Am)

[Eagle]

Ok, I have a 2003 Grand Am 3.4L 6cyl. It has somewhere between 38-39,000mi. A few weeks ago the check engine light came on for no apparent reason, the car was running fine, I didn't want to take the car somewhere just to have them tell me that it was nothing, or that it was some pathetic problem that I could fix myself, so I ordered a scanner. Well, by Murphys Law the light went out on its own the day before the scanner arrived, so I figured it was nothing. Then a couple days ago I was driving down the highway, had the cruise control going, I hit a slight bump (not major by any measure) and the cruise cut out. Nothing I did got it to turn back on. I tried it again latter on while on my way home and it worked fine. The following day (yesterday) I left for work, and the cruise would not engage at all, and the turn indicators were blinking extra fast. All lights were working, and the 4-ways worked fine, just the turns were doing double time. When I left work yesterday afternoon, I was backing out of the parking spot, and the digital odometer flickered allong with the dashboard indicator light for the fog lamps. As soon as I put it in drive it all worked fine. I was able to engage the cruise, but once again hit a slight bump, and it died on me. A mile or so up the road, I tried it and it worked again. Today, same batch of problems both monring and afternoon minus the cruise worked all the way home. Both mornings were extra cold. The dash and odo did not blink this morning while in reverse, just both afternoons. A friend thinks it may be the computer, said he has a friend whith a 2000 or so Malibu and just paid $1500 for a new computer. Any thoughts? Are all these problems related and just one heck of a coincidence?

[Lohman446]

If he paid $1500 for a GM computer he got ripped.

Its unlikely that it is the computer.

Ignition switch, multifunction switch would be my first wild guesses without seeing the vehicle. If this has the flasher unit in the dash (if the hazard light button is dash mounted) these are a fairly common problem but should not influence your cruise.

I would lean towards ignition switch.

[Eagle]

ohter ideas I've gotten from an automotive forum are the Body Control Modual, center brake light, and brake light switch. any other ideas?

[skife]

FYI, if SES light comes on take it to autozone or advanced autoparts and they will throw it on the computer for free.

[Lohman446]

ohter ideas I've gotten from an automotive forum are the Body Control Modual, center brake light, and brake light switch. any other ideas?

Wiring - it is conceivable it is all caused by a broken / loose wire somewhere.

[bornl33t]

check your fuses, cruise control has a fuse in GMs and uber fast blinkers could be either a fuse or a bad bulb.

if all that checks out find your battery and make sure both leads are corrosion free, and while your at it check to see if your ground (the black one) is securely fastened to the frame, again without corrosion.


I highly doubt it's the computer but if you got a scanner plug it up anyway, GM's since the early 90's store a fault code for up to 90 days or until cleared out.

Does the car have an aftermarket head unit? Could be someones hack job, man I've seen some crazy stuff there.....

[thecavemankevin]

check your fuses, cruise control has a fuse in GMs and uber fast blinkers could be either a fuse or a bad bulb.

if all that checks out find your battery and make sure both leads are corrosion free, and while your at it check to see if your ground (the black one) is securely fastened to the frame, again without corrosion.


I highly doubt it's the computer but if you got a scanner plug it up anyway, GM's since the early 90's store a fault code for up to 90 days or until cleared out.

Does the car have an aftermarket head unit? Could be someones hack job, man I've seen some crazy stuff there.....

actually yes he does have an after market radio in there. and now that i think of it he did have some difficulty in figuring out how to do it because GM has computer controls in the stock unit or something like that. If i recall he ordered a "little black box" of some sort that he had to plug into some of the stock wire and then of course run the rest of the wires into the radio. But i certainly wouldn't consider it a hack job. it was all quite clean and done with quick disconnects (no hacking and soldering/electrical tape). but perhaps something is loose inside.

i too was going to recommend you check your ground Eric, but now i suggest you yank the radio and make sure all is well inside there.

[Oldest Sage]

The cruise runs thru the brake switch assy and if it's close to actuating position that could give you the cruise problem. Just changed one in a 92, what a pain to adjust. Usually, a rapid flashing directional is a bad bulb. I'm sure you've already checked these? The whole thing could be caused by a main plug that runs most of the wires from the eng compartment to the cockpit. Unplug and reconnect this and see if it fixes the problems.

[Eagle]

fuses are good, already checked them. The radio wasn't a hack job, got the wiring and 'little black box' all as one from Circuit City. Lights are good, already checked. What bewilders me is that it is the same probems at the same times of day every day, but different problems in the morning vs afternoon. I'm thinking it's probably a ground somewhere, just not sure where.

[punkncat]

I was going to suggest what has been said several times. Check the battery ground and power terminals and connections. Check the fusable link in the positive side of the cable if equipped.
There is either a wire loose or a bad connection somewhere IMO.

[thecavemankevin]

I was going to suggest what has been said several times. Check the battery ground and power terminals and connections. Check the fusable link in the positive side of the cable if equipped.
There is either a wire loose or a bad connection somewhere IMO.

yeah, double check the fuse lead, but redo both battery terminal connections and then redo the main ground where the neg lead from the battery hits frame. You may want to sand it, and grease it to be sure of a good new connection.