Mechanics

WHY DO MY DASHBOARD INDICATOR LIGHTS RANDOMLY COME ON/STAY ON WHEN I START/DRIVE MY CAR?

2001 Saturn SL2 • 180,000 miles

The indicator lights on my 2001 Saturn SL2 sedan randomly come on and stay on from time to time when I start and drive my car. If I shut the car off and restart it, the same or different indicator lights may come on and stay on until the car is shut off again. The most common lights are the "fasten seatbelt" light, which will stay on either blinking or solid, even though my seatbelt and that of my passengers is fastened; the "security" "and "service engine" light also come on and stay on together, but not all of the time. Other times, no indicator lights are on while the car is running. I have checked the fuses for these things and they tested good. I have also tried changing the fuses, but the problem continues. More recently my automatic door locks are malfunctioning -- when I unlock the drivers side door, the outside handle will stay flipped up and the door latch will not engage when I try to close it. Today the locks were apparently clicking when I got home, but my driver's door would not unlock or open. I could open the passenger door but not the driver's door. My mechanic told me some months ago that all of this could indicate a problem with the alternator. He said that since it was "intermitant" I should wait until it fails completely! Six months later, the car is running fine, but the random dashboard lights and the lock problems continue. What is wrong with my car?
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Seamusslass
January 6, 2012.



Indeed it could be the generator. Starting with the '87 model year, GM went from the second best design to the world's worst pile ever. Start by having it load tested with a tester that also performs a "ripple" test. If the ripple is high and the maximum output current is close to one third of its rated capacity, it has a failed diode. That is real common. The generators develop huge voltage spikes that can destroy those diodes and internal voltage regulator as well as interfere with sensor signals and the operation of the many computers on the car. It is very common to go through four to six generators in the life of the car. To reduce the number of repeat failures, replace the battery at the same time. As they age, they lose their ability to dampen and absorb those voltage spikes. Your old battery will work fine in an '86 or older car.

Caradiodoc
Jan 6, 2012.
Just to add to this one I totally disagree with the alternator theroy. The older externally cooled alternators on the saturn S models failed commonly. But when they went to the internally cooled alternators in the later made 1998-2002 S models those alternators were really good and didnt fail that often.I have seen them last well over 200,000 miles. It sounds more like your body control module is failing. Which controls everything your saying is going crazy.

Saturntech9
Jan 7, 2012.
Also what code numbers were read from the computer?Those would help also.

Saturntech9
Jan 7, 2012.
Thanks for your answers. I will check these things out. FYI for saturntech9. No code numbers came up on the computer when my mechanic ran the diagnostic. However, the problem is sporadic, so it is difficult to have the mechanic witness the problem, since it happens randomly.

Tiny
Seamusslass
Jan 8, 2012.
Sorry it took so long to get back to you iam not getting email alerts letting me know someone responded when I answered a question. So did he scan the body control module for codes also?When the body control modules go bad they never set codes and tell on themselves. Some times you will get a code U1000 set in the ecm for not being able to talk to the body control module. But most of the time you dont even get that. So how often does it act up?

Saturntech9
Jan 8, 2012.
No worries. I actually think your response time on this site is very quick! I think my mechanic just ran the basic computer diagnostic. I don't think he even suspected to check the body control module, because he was thinking it was the alternator/generator. I am curious how a scan of the body control module is different? Is this something any shop can do and what sort of fee (ballpark) would they charge? I have been seeing dashboard indicator lights go on and off at random for about 8 months. These are especially the "fasten seat belt" light, which blinks or stays solid while the car is running, and the "security" combined with the "service engine" light. This is the one that worries me because I am wondering if this is going to at some point disable the car from starting! I would love to solve this, but have done nothing so far since no one can diagnose what to repair.

Tiny
Seamusslass
Jan 10, 2012.
Just an added note. The frequency of the dash indicator lights acting up is almost every day.

Tiny
Seamusslass
Jan 10, 2012.
To scan the body control module for codes takes it takes a alot more advanced and expensive scan rather the basic one that just reads engine and transmission codes. The guy that did it for you I would ask if his scanner can read those codes and if he even checked for codes in the body control module. With the symptoms you have it doesnt sound like a bad alternator to me. Sounds totally like a body control module one thing I would try is if I was working on the car I would swap out the body control module with my used tester module to see if that fixed the problem. If it did then I have you put a new body control module in.

Saturntech9
Jan 10, 2012.
Thanks! This information is very helpful! What is the urgency of repairing this.I.E. What can go wrong in the meantime? Will I just continue to experience random dash lights, or can this affect the car running? I have had this car for 8 years and don't hope to have it much longer.

Tiny
Seamusslass
Jan 10, 2012.
The body control module can cause the car not to start depending on what part of it fails. If the security light is coming on then thats what would worry me. So is there other problems with the car besides the dash lights coming on?You said you wont have the car much longer so I was wondering if there was a reason for getting rid of the car?The S model saturns are my favorite model I have a 1999 saturn SL2 with over 220,000 miles and I love the car.

Saturntech9
Jan 10, 2012.
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