eng Reduced power/service ESC/number of codes
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From: Colorado Springs, CO
eng Reduced power/service ESC/number of codes
09' SS Sedan. 70k ish miles. The issue has been around for awhile, but it is suddenly getting much worse.
Originally, the car would randomly stumble and then be fine. Then it started going into reduced engine power and would also display "service ESC" message and SES. This has happened as I start the car or during normal driving. It doesn't seem to be anything specifically that causes the condition. Turning the car off and then on puts it back to normal (Especially fun at highway speeds).
I took the car to the dealer and they claimed I need to replace the mass airflow sensor, throttle body, and EVAP canister. They claimed it was a combination of those parts causing the issue. Doesn't really make since to me, so I declined the service.
They cleared the codes and the car drove fine until this morning. On the way to work it seemed to drive fine other than limiting boost to about 3psi. It had never done this and tripped P0100 and P0102, which are MAF issues it seems. Later, I started the car and it immediately went into reduced power and tripped a number of codes.
In addition to the ones previously mentioned;
P0401 EGR flow insufficient detected
P0001 Unknown
P0221 throttle/pedal position sensor switch "B" circuit range performance problem
P1921 Unkown
I'm pretty sure it has also tripped P0121 and a cycling misfire code in the past, but not this time for some reason.
Where do you guys think I should start? Do you need any more info? I have read that it could be a number of things to include a bad wire or even a shot ECU. I don't plan on handing over a grand to the stealership.
Originally, the car would randomly stumble and then be fine. Then it started going into reduced engine power and would also display "service ESC" message and SES. This has happened as I start the car or during normal driving. It doesn't seem to be anything specifically that causes the condition. Turning the car off and then on puts it back to normal (Especially fun at highway speeds).
I took the car to the dealer and they claimed I need to replace the mass airflow sensor, throttle body, and EVAP canister. They claimed it was a combination of those parts causing the issue. Doesn't really make since to me, so I declined the service.
They cleared the codes and the car drove fine until this morning. On the way to work it seemed to drive fine other than limiting boost to about 3psi. It had never done this and tripped P0100 and P0102, which are MAF issues it seems. Later, I started the car and it immediately went into reduced power and tripped a number of codes.
In addition to the ones previously mentioned;
P0401 EGR flow insufficient detected
P0001 Unknown
P0221 throttle/pedal position sensor switch "B" circuit range performance problem
P1921 Unkown
I'm pretty sure it has also tripped P0121 and a cycling misfire code in the past, but not this time for some reason.
Where do you guys think I should start? Do you need any more info? I have read that it could be a number of things to include a bad wire or even a shot ECU. I don't plan on handing over a grand to the stealership.
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09' SS Sedan. 70k ish miles. The issue has been around for awhile, but it is suddenly getting much worse.
Originally, the car would randomly stumble and then be fine. Then it started going into reduced engine power and would also display "service ESC" message and SES. This has happened as I start the car or during normal driving. It doesn't seem to be anything specifically that causes the condition. Turning the car off and then on puts it back to normal (Especially fun at highway speeds).
I took the car to the dealer and they claimed I need to replace the mass airflow sensor, throttle body, and EVAP canister. They claimed it was a combination of those parts causing the issue. Doesn't really make since to me, so I declined the service.
They cleared the codes and the car drove fine until this morning. On the way to work it seemed to drive fine other than limiting boost to about 3psi. It had never done this and tripped P0100 and P0102, which are MAF issues it seems. Later, I started the car and it immediately went into reduced power and tripped a number of codes.
In addition to the ones previously mentioned;
P0401 EGR flow insufficient detected
P0001 Unknown
P0221 throttle/pedal position sensor switch "B" circuit range performance problem
P1921 Unkown
I'm pretty sure it has also tripped P0121 and a cycling misfire code in the past, but not this time for some reason.
Where do you guys think I should start? Do you need any more info? I have read that it could be a number of things to include a bad wire or even a shot ECU. I don't plan on handing over a grand to the stealership.
Originally, the car would randomly stumble and then be fine. Then it started going into reduced engine power and would also display "service ESC" message and SES. This has happened as I start the car or during normal driving. It doesn't seem to be anything specifically that causes the condition. Turning the car off and then on puts it back to normal (Especially fun at highway speeds).
I took the car to the dealer and they claimed I need to replace the mass airflow sensor, throttle body, and EVAP canister. They claimed it was a combination of those parts causing the issue. Doesn't really make since to me, so I declined the service.
They cleared the codes and the car drove fine until this morning. On the way to work it seemed to drive fine other than limiting boost to about 3psi. It had never done this and tripped P0100 and P0102, which are MAF issues it seems. Later, I started the car and it immediately went into reduced power and tripped a number of codes.
In addition to the ones previously mentioned;
P0401 EGR flow insufficient detected
P0001 Unknown
P0221 throttle/pedal position sensor switch "B" circuit range performance problem
P1921 Unkown
I'm pretty sure it has also tripped P0121 and a cycling misfire code in the past, but not this time for some reason.
Where do you guys think I should start? Do you need any more info? I have read that it could be a number of things to include a bad wire or even a shot ECU. I don't plan on handing over a grand to the stealership.
P0001 Fuel Volume Reg Ctrl Circ/Open
Cobalts aren't equipped with such system.
P0221 Throttle Pos Sensor/Switch B Circ Range/Perf
This is basically a throttle position (throttle body) vs pedal position correlation issue. The ecm saw either too much or too little of one vs the other for where it expected them to both be at a given position. This would also explain you seeing a P0121 (Throttle Pos Sensor/Switch A Circ Range/Perf). They tend to go hand and hand.
P0401- Exhaust Gas Recirculation Flow Insuff Detected
LNF's don't have an EGR system what so ever, so this code technically shouldn't exist in the system.
P1921 Unkown
This code technically doesn't exist anywhere from what I can find. None of my GM diagnostic nor even Alldata reference this code even existing so that's an odd one.
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From: Colorado Springs, CO
Not to state the obvious but, something is definitely very wrong here. Half of the codes that you're coming with either aren't supported in the LNF's system, or just straight up don't exist at all from what I can see. With that being the case, this says bad or corrupt ecm all over it. Has the car been tuned or flashed for any other reason than to be tuned?
P0001 Fuel Volume Reg Ctrl Circ/Open
Cobalts aren't equipped with such system.
P0221 Throttle Pos Sensor/Switch B Circ Range/Perf
This is basically a throttle position (throttle body) vs pedal position correlation issue. The ecm saw either too much or too little of one vs the other for where it expected them to both be at a given position. This would also explain you seeing a P0121 (Throttle Pos Sensor/Switch A Circ Range/Perf). They tend to go hand and hand.
P0401- Exhaust Gas Recirculation Flow Insuff Detected
LNF's don't have an EGR system what so ever, so this code technically shouldn't exist in the system.
P1921 Unkown
This code technically doesn't exist anywhere from what I can find. None of my GM diagnostic nor even Alldata reference this code even existing so that's an odd one.
P0001 Fuel Volume Reg Ctrl Circ/Open
Cobalts aren't equipped with such system.
P0221 Throttle Pos Sensor/Switch B Circ Range/Perf
This is basically a throttle position (throttle body) vs pedal position correlation issue. The ecm saw either too much or too little of one vs the other for where it expected them to both be at a given position. This would also explain you seeing a P0121 (Throttle Pos Sensor/Switch A Circ Range/Perf). They tend to go hand and hand.
P0401- Exhaust Gas Recirculation Flow Insuff Detected
LNF's don't have an EGR system what so ever, so this code technically shouldn't exist in the system.
P1921 Unkown
This code technically doesn't exist anywhere from what I can find. None of my GM diagnostic nor even Alldata reference this code even existing so that's an odd one.
Thanks for the info. Original owner had a trifecta tune and downpipe. I returned the car to stock when I purchased it and haven't had any issues like this for about 4 years.
I'm using a BAFX scanner and torque app to pull codes. Could there be an issue with the scanner or program? I suppose I could go over to autozone once our frozen tundra thaws out and make sure their scanner says the same thing.
I don't THINK it's evap related. About a year ago I got he pesky check gas cap message. Purge solenoid checked out ok (although it's entirely possible it's gone bad since then) and I replaced the vent solenoid. Ended up being a partially clogged canister vent pipe causing the issue. There's actually a technical bulletin for this if anyone is experiencing the same issue.
For a service esc code or diagnostic, you won't be able to do anything with the code unless you have a gmtech tool or a name brand scanner. My scanner wouldn't pick up any codes related to the esc. Went to my buddies shop and used their snap on scanner and broke the code down to actually was because they are stored in the abs module.
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For a service esc code or diagnostic, you won't be able to do anything with the code unless you have a gmtech tool or a name brand scanner. My scanner wouldn't pick up any codes related to the esc. Went to my buddies shop and used their snap on scanner and broke the code down to actually was because they are stored in the abs module.
Also, I had a snow day so I just went to see if I could find any loose wires or anything and I find a line unplugged and placed in such a manner that only a human could have done it. I will be sending an email to the dealership, but could you tell me what the line is for? The airbox was actually not even attached, so I'm really curious about wtf they were doing over there. Attached a picture of how I found it.
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From: Colorado Springs, CO
Car runs much better obviously. Went into reduced engine power mode again on start up though and tripped P2119 (throttle actuator control throttle body range/performance) and P2101 (throttle actuator control motor circuit range/performance).
So is it a bad TAC module? Is there a way to test it even though it's so intermittent? If it is bad, can I replace it without replacing the entire throttle body?
Thanks for the help
So is it a bad TAC module? Is there a way to test it even though it's so intermittent? If it is bad, can I replace it without replacing the entire throttle body?
Thanks for the help
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