DTC gurus in here plz

[tofu]

I drove from Houston to Baton Rouge tonight to see my gf. Just as I was getting into BR (about 240 mile drive/ 4-5hrs) when my Cobalt suddenly went into limp mode and the message center popped up w/ the "engine power reduced" msg. I scanned for DTC's w/ the aeroforce gauge and it returned the codes:

P2101 Throttle Actuator Position Performance -PCM
B1516 Battery Current Sensor Performance -BCM

Anyway, the P2101 was apparently caused by the "boost-bypass mod"...I was running Alpha's version of it, and unplugged the line, stuck it back onto the nipple and it took the car out of limp mode and everything has been okay for about an hour (since it happened). Has anyone else ran into this w/ the bypass mod? I've had the line plugged for almost 2-3 months with no problems...strange. And as far as the B1516 code I am clueless.

Any help/info would be greatly appreciated.

[mailmars]

Originally Posted by tofu

I drove from Houston to Baton Rouge tonight to see my gf. Just as I was getting into BR (about 240 mile drive/ 4-5hrs) when my Cobalt suddenly went into limp mode and the message center popped up w/ the "engine power reduced" msg. I scanned for DTC's w/ the aeroforce gauge and it returned the codes:

P2101 Throttle Actuator Position Performance -PCM
B1516 Battery Current Sensor Performance -BCM

Anyway, the P2101 was apparently caused by the "boost-bypass mod"...I was running Alpha's version of it, and unplugged the line, stuck it back onto the nipple and it took the car out of limp mode and everything has been okay for about an hour (since it happened). Has anyone else ran into this w/ the bypass mod? I've had the line plugged for almost 2-3 months with no problems...strange. And as far as the B1516 code I am clueless.

Any help/info would be greatly appreciated.

Turning the car off is what cleared the 2101 code and most likely the 1516 also. The p2101 Throttle Actuator Position Performance is caused when the when the pedal position and the actuator for the throttle are outside of the calibrated range and thus threw it into reduced power mode. For the B1516, I have no idea. The 2005 ION FSM does not have the code listed. I am sure it is valid, the FSM simply does not have it listed or it is a Cobalt code that I do not have access to. My best guess is that something caused a power drop and the throttle position got lost. Did you almost stall the car? What was/did happen when it went south on you.


Mark

[crazybrew609]

B1516 is

"Sets as current when the duty cycle of the PWM (pulse width modulation)input signal is less than 4 percent or more than 96 percent for more than 33 seconds"

prolly just a reaction from the TAP fluke

[mailmars]

Originally Posted by crazybrew609

B1516 is

"Sets as current when the duty cycle of the PWM (pulse width modulation)input signal is less than 4 percent or more than 96 percent for more than 33 seconds"

prolly just a reaction from the TAP fluke

I would venture to guess that this caused the TAP failure.

Mark

[WopOnTour]

Unlike the Redline, your Cobalt uses a BCM Regulated Voltage Control system.
That DTC is most likely set if the "battery current sensor" has been disconnected when the engine was started and running for 30 seconds. It's near the battery , your ground cable passes "through" the RVC sensor. Maybe you were working in the trunk area recently and disconnected it? Check your 2 battery connections and call be in the morning...
WopOnTour

[mailmars]

Originally Posted by WopOnTour

Unlike the Redline, your Cobalt uses a BCM Regulated Voltage Control system.
That DTC is most likely set if the "battery current sensor" has been disconnected when the engine was started and running for 30 seconds. It's near the battery , your ground cable passes "through" the RVC sensor. Maybe you were working in the trunk area recently and disconnected it? Check your 2 battery connections and call be in the morning...
WopOnTour

Ahhh the GM man has spoken. Hell I have been dabbing for a while on the redline and am just starting to get a grip on some of the systems....


Mark

[tofu]

Originally Posted by mailmars

Turning the car off is what cleared the 2101 code and most likely the 1516 also. The p2101 Throttle Actuator Position Performance is caused when the when the pedal position and the actuator for the throttle are outside of the calibrated range and thus threw it into reduced power mode. For the B1516, I have no idea. The 2005 ION FSM does not have the code listed. I am sure it is valid, the FSM simply does not have it listed or it is a Cobalt code that I do not have access to. My best guess is that something caused a power drop and the throttle position got lost. Did you almost stall the car? What was/did happen when it went south on you.


Mark

Thanks for the responses fellas..

Well the interesting thing is when I turned the car off and back on (after about 5 minutes), it immediately went into limp mode again. I tried clearing the codes from the aeroforce gauge and it would work for about 10 seconds then go back into limp mode. Finally I unplugged the bypass line and put it back onto the solenoid and started her back up, everything was fine. I erased the codes and drove to my g/f's apartment with no problems.

I'm going to go check on that "RVC" sensor WOP was talking about...I sure hope it's unpluggged and there isn't some sort of electrical problem...

Thanks again.

[tofu]

Okay I checked the battery and RVC sensor (assuming I was tinkering w/ the right part) and everything checked out okay. I unplugged it and plugged it back in to be sure. Right now I am not running the boost bypass (if that has anything to do with it) and it is running fine, no DTC's so far. Interesting enough, w/o the bypass I am still hitting, according to the Aeroforce gauge, 15psi...same as I was when I was running the bypass.

[WopOnTour]

well others have reported that DTC with the boost mod- although personally I've never been able to rationalize why the mod would affect it. At least based on the published enable/fail criteria...
See if it happens again next time you do the boost mod I guess, and look for a bad connection on the current sensor on your negative battery cable.
WOT