Need help validating the diagnosis of dealership
Need help validating the diagnosis of dealership
From my throttle cutting topic, you'll see I had the following problems:
Thruttle cut to 1/4 when 1/2 to 3/4 throttle is applied. Heavy acceleration halted or sputtered. Cruise control is unusable.
Problem disentigrates after a mile of driving.
Here is the dealerships diagnosis:
YAW Control system is whacky. "System that controls the braking of engine under G's is off. When I turn left, the YAW says right. Readings are all messed up"
$800 for new unit.
Am I being thrown for a loop?
Thruttle cut to 1/4 when 1/2 to 3/4 throttle is applied. Heavy acceleration halted or sputtered. Cruise control is unusable.
Problem disentigrates after a mile of driving.
Here is the dealerships diagnosis:
YAW Control system is whacky. "System that controls the braking of engine under G's is off. When I turn left, the YAW says right. Readings are all messed up"
$800 for new unit.
Am I being thrown for a loop?
No suspension or steering work done at all. Only thing I can think of is that after I took it in there last, my tire pressure readings have been switched so that Rear reads the front tires, and F: reads the rear tires. But the tires themselves have not been switched...
I didn't read your other thread but I think there is a way to reset the throttle position. I'm not sure exactly what the procedure is called but there is some information I read about it on this site. I think the procedure is one of those where your ecu relearns the throttle positions. Hopefuly someone that knows what I'm talking about can link it.
Originally Posted by Fingers
I didn't read your other thread but I think there is a way to reset the throttle position. I'm not sure exactly what the procedure is called but there is some information I read about it on this site. I think the procedure is one of those where your ecu relearns the throttle positions. Hopefuly someone that knows what I'm talking about can link it.
Originally Posted by iceagetlc
From my throttle cutting topic, you'll see I had the following problems:
Thruttle cut to 1/4 when 1/2 to 3/4 throttle is applied. Heavy acceleration halted or sputtered. Cruise control is unusable.
Problem disentigrates after a mile of driving.
Here is the dealerships diagnosis:
YAW Control system is whacky. "System that controls the braking of engine under G's is off. When I turn left, the YAW says right. Readings are all messed up"
$800 for new unit.
Am I being thrown for a loop?
Thruttle cut to 1/4 when 1/2 to 3/4 throttle is applied. Heavy acceleration halted or sputtered. Cruise control is unusable.
Problem disentigrates after a mile of driving.
Here is the dealerships diagnosis:
YAW Control system is whacky. "System that controls the braking of engine under G's is off. When I turn left, the YAW says right. Readings are all messed up"
$800 for new unit.
Am I being thrown for a loop?
I think one of the following may be the case, so I'd try these in order:
1st of all, if you have any check engine codes, which you don't mention, you should get those checked immediately
MAF dirty / damaged ... check it and clean with MAF Spray cleaner from autozone
Throttle body dirty ... check it and clean with Carburetor cleaner
After checking the above 2 items, FULLY RESET the ECU not by the pedal reset method, but by disconnecting the negative battery terminal overnight
Then, try the procedures here (not the ECU reset though, the ones relating to throttle):
http://www.technosquareinc.com/350reset.htm
Spark Plugs fouled ... check and replace if necessary
Last edited by Wired 24/7; Jun 14, 2007 at 12:43 PM.
I think I'd also get a Consult II or Cipher on there and run a few logs to see what is going on with the ECU. I was able to diagnose excessive exhaust blockage that way... I agree with Wired that the Yaw sensor theory doesn't add up.
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Originally Posted by gothchick
I think I'd also get a Consult II or Cipher on there and run a few logs to see what is going on with the ECU. I was able to diagnose excessive exhaust blockage that way... I agree with Wired that the Yaw sensor theory doesn't add up.
Exhaust blockage? Can you PM me with some details?
i had this exact same problem, and just it resolved last weekend.
it was an ecu issue. it had to do with the brake switch.
basically the ecu thought that the brakes were applied when they were not, and was cutting power.
the dealer ordered a new ecu (under warranty) and it fixed the problem. they attributed the problem to a physical short in the ecu.
it was an ecu issue. it had to do with the brake switch.
basically the ecu thought that the brakes were applied when they were not, and was cutting power.
the dealer ordered a new ecu (under warranty) and it fixed the problem. they attributed the problem to a physical short in the ecu.
Originally Posted by Moroccan_Mole
i had this exact same problem, and just it resolved last weekend.
it was an ecu issue. it had to do with the brake switch.
basically the ecu thought that the brakes were applied when they were not, and was cutting power.
the dealer ordered a new ecu (under warranty) and it fixed the problem. they attributed the problem to a physical short in the ecu.
it was an ecu issue. it had to do with the brake switch.
basically the ecu thought that the brakes were applied when they were not, and was cutting power.
the dealer ordered a new ecu (under warranty) and it fixed the problem. they attributed the problem to a physical short in the ecu.
Originally Posted by Moroccan_Mole
i had this exact same problem, and just it resolved last weekend.
it was an ecu issue. it had to do with the brake switch.
basically the ecu thought that the brakes were applied when they were not, and was cutting power.
the dealer ordered a new ecu (under warranty) and it fixed the problem. they attributed the problem to a physical short in the ecu.
it was an ecu issue. it had to do with the brake switch.
basically the ecu thought that the brakes were applied when they were not, and was cutting power.
the dealer ordered a new ecu (under warranty) and it fixed the problem. they attributed the problem to a physical short in the ecu.
Your ecu problem
Originally Posted by Moroccan_Mole
i doubt it
Did your problem go away after a mile or so of driving, like mine? How similar was it to what I described?
you can disengage power to the yaw sensor (the vdc and slip lights will come on) to easily test the theory. look for a thread about putting in a switch to cut power to the yaw sensor (to allow burnouts, brake boosting etc).
i think if you look under the center arm rest, you can just disengage the harness to the sensor.
i think if you look under the center arm rest, you can just disengage the harness to the sensor.
Originally Posted by iceagetlc
Did your problem go away after a mile or so of driving, like mine? How similar was it to what I described?
it let up occasionally, very rarely .... and run fine, but it was random.
Originally Posted by Moroccan_Mole
pretty much exact. cruise control didn't work. the car would still rev up, but past maybe 3500 RPM it revved very slowly - like there was no power. If i put my foot to the floor it, would act like it would start to go, but there was no power.
it let up occasionally, very rarely .... and run fine, but it was random.
it let up occasionally, very rarely .... and run fine, but it was random.
Bingo, down to the rpm and everything...
make sure to bring all of your keys with you to the dealer, they will need to re-program all of them. also check your brake lights after thier done. mine stopped working, and i had to bring it back to the dealer.
Originally Posted by iceagetlc
Wow, that's weird. It happened RIGHT after I installed my new LED tail lights... Possible explanation?
Last edited by Fingers; Jun 15, 2007 at 03:41 PM.
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