Oldsmobile/Buick Repair/98 Park Ave
QUESTION: I have seen where you talked about cruse control not working when the check engine light is on. I have had transmission work done this week and I just picked up the car and it is shifting hard telling me that I may have a vacuum leak and then the cruse stopped working on the way home and the check engine light came on. Does this make sense? It is the only thing that makes sense to me, can you please confirm so I can explain it to my mechanic.
ANSWER: HI CAROLYN, THE CK ENG LIGHT WILL NOT EFFECT THE CRUISE CONTROL ON [MOST] GM CARS..IT WILL ON MANY FOREIGN MAKES. I WOULD NEED TO CK THE WIRING DIAGRAM ON YOU CAR TO BE SURE...I WOULD LIKE YOU TO CK THE FUSES IN CAR NOT THE ONES UNDER THE HOOD. SEE IF A FUSE BLEW..IF NOT IT IS POSSIBLE THAT WHEN THEY WERE WORKING ON THE TRANSMISSION THEY COULD OF HIT THE WIRING TO THE CRUISE CONTROL KNOCKING IT OFF OR PULLING ON THE WIRING HARNESS TO SERVO OR THEY COULD OF REMOVED OR BROKEN A VACUUM LINE TO THE SERVO CRUISE CONTROL UNIT UNDER HOOD. THIS WOULD CAUSE A VACUUM LEAK WHICH WOULD AFFECT THE CRUISE... BUT YOUR TRANSMISSION DOES NOT SHIFT BY VACUUM. IT IS CONTROLLED BY THE PCM [COMPUTER] AND SOLENOIDS IN THE VALVE BODY ITSELF..THE HARSH SHIFTING COULD BE CAUSED BY A STICKY SHIFT SOLENOID...LET ME KNOW HOW THIS WORKS OUT FOR YOU,,GOOD LUCK TO YOU,,TOM
PS. YOU COULD REMOVE THE NEGATIVE BATTERY CABLE FOR 30 MINUTES RE-CONNECT IT AND THE CK ENG LIGHT WILL BE OFF.[CODES WILL BE CLEARED] FROM THE PCM >> DRIVE IT AND SEE IF THE CRUISE WORKS LIKE THIS, IN TILL THE CK ENG LIGHT TURNS ON AGAIN..
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This is where I got the first information and I will try disconnecting the battery but I can't help but think that if my engine is not running well, it affects my shifting in my transmission, at least it use to in my older S-10 Blazer. All that I know for sure is that I just picked up the car from the shop that did warranty work on the transmission and it was shifting hard and at about 40 miles down the road the cruise kicked off and the check engine light came on and stayed on. I will take it to a Auto Zone and have them do a code check.
ANSWER: HI CAROLYN, I DID NOT KNOW THAT YOUR ENG WAS RUNNING POORLY,ONLY THAT THE CK ENG LIGHT WAS ON.. YOU DID NOT TELL ME THIS..IF THIS IS THE CASE THIS WILL EFFECT THE SHIFT POINTS OF YOUR TRANSMISSION. THE PCM WILL THINK THE VACUUM SHOULD BE HIGHER THAT IT IS CAUSING ERRATIC SHIFT POINTS. BUT AS FAR AS THE CRUISE CONTROL GOES YOU MAYBE CORRECT AS I SAID ABOVE.I WOULD NEED TO SEE A WIRING DIAGRAM FOR THIS.. I WOULD TAKE THIS CAR AND GET THE CODE READ AND HAVE THEM CLEAR THE CODE IF THEY WILL AND THEN DRIVE IT. IF THE CRUISE CONTROL WORKS YOU WERE CORRECT IN YOUR THINKING. MAKE SURE YOU REMEMBER THE CODE IN CASE THE LIGHT DOES NOT COME BACK ON WHEN YOU TAKE THE CAR BACK TO HAVE IT SERVICED. THE SHOP WILL NEED TO KNOW WHAT CODE WAS IN THE SYSTEM..
ALSO IF THE PLACE THAT READS THE CODE FOR YOU WILL NOT RESET THE PCM TO TURN OFF THE CK ENG LIGHT THIS IS WHEN YOU CAN REMOVE THE NEGATIVE BATTERY POST FOR 30 MINUTES THIS WILL CLEAR IT FOR YOU AND REMOVE THE CODE FROM THE PCM MEMORY.. THIS IS WHY YOU SHOULD REMEMBER WHAT CODE WAS IN THE SYSTEM....I HOPE THIS HELPS YOU AND IF YOU NEED MORE INFO PLEASE GET BACK TO ME..GOOD LUCK TO YOU,,,TOM.
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QUESTION: Hey Tom, I drove it to Auto Zone and had them read the code (P0502)and it turns out to be a Speed Sensor A circuit low input. Now my speedometer is not working either so I believe this is the problem along with the cruise being out of wack. It is lurching too when turns out to be related to this sensor so I have called the repair shop to come and get her and fix it right being still under warranty. I just don't get how they test drove the car, gave it a clean bill of health and it took me driving it 40 miles to find that there was still a problem. What am mess, but I so appreciate everything you have tried to do to help!
HI CAROLYN, YES THIS MAKES ALL THE SENSE IN THE WORLD..THIS EXPLAINS THE BAD SHIFT POINTS AND NO CRUISE CONTROL...DON'T BE TO HARSH ON THE REPAIR SHOP. LOL] SOMETIMES THESE THINGS JUST DON'T SHOW UP UN TILL LATER ON DOWN THE ROAD. ALSO THIS WILL HAVE NO BEARING ON THE POOR RUNNING ENG PROBLEM THAT YOU SAY YOU HAVE. YOU MAY WANT TO TELL THEM ABOUT THIS PROBLEM AS WELL SO THEY DO NOT OVER LOOK IT. LET ME NOW HOW YOU MAKE OUT. GOOD LUCK TO YOU,,,TOM