c5 corvette motor shuts off when air is turned on
08-06-2016, 02:02 PM
#1
c5 corvette motor shuts off when air is turned on
Can anyone give me some advice on what the problem could be! My car will crank right up and run either till the fan kicks on or the ac is turned on, After that it just shuts off!!
08-06-2016, 02:22 PM
#2
1/4 mile/AutoX
check codes and battery voltage, do the belts squeal when AC turned on=bad compressor ???
08-06-2016, 02:37 PM
#3
Just went to parts store yesterday and swapped out my Optima Gel Battery for a new one just to make sure the other battery wasn't what the problem was. belts do not squeal at all compressor is good. If we let the car run till the temp gets high enough for the fans to kick on it shuts the engine down. or if we get in and cut the air on it shuts down.
08-06-2016, 02:47 PM
#4
1/4 mile/AutoX
Just went to parts store yesterday and swapped out my Optima Gel Battery for a new one just to make sure the other battery wasn't what the problem was. belts do not squeal at all compressor is good. If we let the car run till the temp gets high enough for the fans to kick on it shuts the engine down. or if we get in and cut the air on it shuts down.
The following users liked this post:
Red Robin (08-06-2016)
08-06-2016, 03:41 PM
#5
Melting Slicks
I bet on the air compressor. Motor will run until the air compressor clutch engages, is what happened to me on another car I owned. Not sure about the fan issue though???
The following users liked this post:
Red Robin (08-06-2016)
08-06-2016, 03:43 PM
#6
BCM - B2723H
10-PCM- P1571HC
10-PCM- P1644HC
These are the codes I'm getting
For some unknown reason the car is running now even with the air working? Although I did get the pull key wait 10 seconds message and the service column lock crap. We ordered the part to fix that issue though it should be here by Monday and then maybe I won't get stranded and look like an idiot in public!
10-PCM- P1571HC
10-PCM- P1644HC
These are the codes I'm getting
For some unknown reason the car is running now even with the air working? Although I did get the pull key wait 10 seconds message and the service column lock crap. We ordered the part to fix that issue though it should be here by Monday and then maybe I won't get stranded and look like an idiot in public!
Last edited by Red Robin; 08-06-2016 at 03:50 PM. Reason: added a follow up
08-06-2016, 04:33 PM
#7
Were those the ONLY codes that you got when you pulled the codes??? I would have expected some TCS errors or perhaps RCS NO COMM
None of those should have resulted in the engine turning off.
I also would have expected additional BCM error codes related to the Column Lock system if you are getting the "Pull key....." message. Re-pull all the codes to make certain you did not miss any.
The "Pull key..." message could result in the engine shutting off if you attempted to DRIVE the car with that message displayed but by itself with the engine just idling it should NOT cause other problems.
None of those should have resulted in the engine turning off.
I also would have expected additional BCM error codes related to the Column Lock system if you are getting the "Pull key....." message. Re-pull all the codes to make certain you did not miss any.
The "Pull key..." message could result in the engine shutting off if you attempted to DRIVE the car with that message displayed but by itself with the engine just idling it should NOT cause other problems.
10-pcm-p0480h
10-pcm-p0481h
10-pcm-p0530h
10-pcm-p1571hc
10-pcm-p1644hc
28-TCS No Comm.
38-RTD No Comm.
40-BCM B2723H
60-IPC No Codes
AO-LDCM
B2252H
B2282H
B2284H
B2262H
A1-RDCM
B2283H
B2285H
U1064H
I think there was a couple more but I was only able to get these for now.
08-06-2016, 04:50 PM
#8
1/4 mile/AutoX
if your getting the column lock message that is your problem, along with the column lock the fuel pressure is set to 2# and it will die as soon as you put it in gear.
08-06-2016, 05:01 PM
#9
We already know about the pull key wait ten seconds and the service column lock issue. The problem is that it has already been fixed because my column doesn't lock when it goes dead plus I can pull my key out of the ignition when I've got the car running. we ordered the LMC5 module to fix this issue from Compliance Parts, LLC. We have dealt with those error codes since we bought the car but it use to not happen that much. Now we just take the battery cables off and reset the computer if it takes to long to start it. probably not the best idea but nobody likes to be stuck somewhere.
08-06-2016, 05:14 PM
#10
1/4 mile/AutoX
We already know about the pull key wait ten seconds and the service column lock issue. The problem is that it has already been fixed because my column doesn't lock when it goes dead plus I can pull my key out of the ignition when I've got the car running. we ordered the LMC5 module to fix this issue from Compliance Parts, LLC. We have dealt with those error codes since we bought the car but it use to not happen that much. Now we just take the battery cables off and reset the computer if it takes to long to start it. probably not the best idea but nobody likes to be stuck somewhere.
08-06-2016, 05:17 PM
#11
Actually there was more codes but the codes I put on here were the ones that wouldn't clear. the other codes were
10-pcm-p0480h
10-pcm-p0481h
10-pcm-p0530h
10-pcm-p1571hc
10-pcm-p1644hc
28-TCS No Comm.
38-RTD No Comm.
40-BCM B2723H
60-IPC No Codes
AO-LDCM
B2252H
B2282H
B2284H
B2262H
A1-RDCM
B2283H
B2285H
U1064H
I think there was a couple more but I was only able to get these for now.
10-pcm-p0480h
10-pcm-p0481h
10-pcm-p0530h
10-pcm-p1571hc
10-pcm-p1644hc
28-TCS No Comm.
38-RTD No Comm.
40-BCM B2723H
60-IPC No Codes
AO-LDCM
B2252H
B2282H
B2284H
B2262H
A1-RDCM
B2283H
B2285H
U1064H
I think there was a couple more but I was only able to get these for now.
My husband was just looking at wires going to the compressor and thought it looked a little rough so he touched it and the compressor came on all of a sudden and the motor DID NOT go dead? He wanted to know what your opinion is on this? Do you think that may have been the issue? He noticed that the wire looked like it had gotten really hot and then noticed the resistor on the wire was just falling apart, it was not getting a good connection. He fixed the wire and now the car is running fine. Do you think that could have been the problem the whole time?
08-06-2016, 05:40 PM
#12
08-06-2016, 06:14 PM
#13
1/4 mile/AutoX
08-06-2016, 08:18 PM
#14
1/4 mile/AutoX
08-06-2016, 08:53 PM
#15
No I'm sorry! I didn't really explain it in detail. I'm kinda new to this.. as far as making sure I explain everything and not sounding like a a**hole. I appreciate your comments and you're very right about the service column lock crap! I've had this car for about 2 years now and slowly learning things about it that a whole lot of other people are having issues with. Thank You for posting!
08-06-2016, 09:00 PM
#16
That is NOT good. That is a problem that you will need to address at some point and the cause is most likely that the key and/or the key cylinder is so badly worn that it cannot properly read key pellet ( code BCM B2723) and may well be related to the "pull key..." message that you are getting.
The BCM reads the pellet on the key for security purposes (VATS or Vehicle Anti Theft System) and senses the removal of the key to complete the column lock function when you are shutting off the engine. The BCM may well not be always able to sense that the key has been removed from the ignition and hence fails to complete the column lock function for the current ignition cycle. As a result the next time you go to start the car the BCM is in an "out of sync" state with respect to the column lock. ie because the previous column lock cycle was never completed the BCM has a status of column unlocked yet it senses the key being put in to start the car and knows the column should be LOCKED and cannot logically make sense of what has happened. Hence it puts up the "Pull key...." message, In short your key cylinder is exaserbating the problems other that you have.
The BCM reads the pellet on the key for security purposes (VATS or Vehicle Anti Theft System) and senses the removal of the key to complete the column lock function when you are shutting off the engine. The BCM may well not be always able to sense that the key has been removed from the ignition and hence fails to complete the column lock function for the current ignition cycle. As a result the next time you go to start the car the BCM is in an "out of sync" state with respect to the column lock. ie because the previous column lock cycle was never completed the BCM has a status of column unlocked yet it senses the key being put in to start the car and knows the column should be LOCKED and cannot logically make sense of what has happened. Hence it puts up the "Pull key...." message, In short your key cylinder is exaserbating the problems other that you have.
08-06-2016, 09:19 PM
#17
1/4 mile/AutoX
That is NOT good. That is a problem that you will need to address at some point and the cause is most likely that the key and/or the key cylinder is so badly worn that it cannot properly read key pellet ( code BCM B2723) and may well be related to the "pull key..." message that you are getting.
The BCM reads the pellet on the key for security purposes (VATS or Vehicle Anti Theft System) and senses the removal of the key to complete the column lock function when you are shutting off the engine. The BCM may well not be always able to sense that the key has been removed from the ignition and hence fails to complete the column lock function for the current ignition cycle. As a result the next time you go to start the car the BCM is in an "out of sync" state with respect to the column lock. ie because the previous column lock cycle was never completed the BCM has a status of column unlocked yet it senses the key being put in to start the car and knows the column should be LOCKED and cannot logically make sense of what has happened. Hence it puts up the "Pull key...." message, In short your key cylinder is exaserbating the problems other that you have.
The BCM reads the pellet on the key for security purposes (VATS or Vehicle Anti Theft System) and senses the removal of the key to complete the column lock function when you are shutting off the engine. The BCM may well not be always able to sense that the key has been removed from the ignition and hence fails to complete the column lock function for the current ignition cycle. As a result the next time you go to start the car the BCM is in an "out of sync" state with respect to the column lock. ie because the previous column lock cycle was never completed the BCM has a status of column unlocked yet it senses the key being put in to start the car and knows the column should be LOCKED and cannot logically make sense of what has happened. Hence it puts up the "Pull key...." message, In short your key cylinder is exaserbating the problems other that you have.
08-06-2016, 11:43 PM
#18
1/4 mile/AutoX
Not trying to impress anyone. Simply trying to point out that the key for the C5 and infact for MOST newer vehicles performs several functions some of which can be/are inter-related.
On the C5 the pellet on the key is a part of the securtity (VATS) system that is intended as a theft deterrent feature. It applies to both manual and automatic trans cars.... The pellet and the cut of the key make up a somewhat unique combination that is intended to help avoid theft of the car by someone that might for example use a screw driver jammed into the key cylinder to turn the ignition switch as they attempt to steal the car. Also the key is part of the Column Lock function which is a left over Federally mandated theft deterrent system. It stems from laws made back in the 1960's where a "column locking" device was required on all manual trans cars as an "added theft deterrent" .
GM like most car manufacturers decided to utilize the same "column locking" function on both manual and automatic trans cars to simplify the build process at the factory and not have to use different components for manual vs automatic cars.
In the case of the C5 the ignition key is NOT on the column so a direct link between the key and the locking mechanism does not exist. So GM needed to be developed way to control the lock motor that locks and unlocks the column from the dash mounted ignition switch. GM chose to tie this into the Body Control Module or BCM. The way it works is that the BCM needs to keep a "state" bit to know if the column is locked or unlocked since the BCM has no physical way to detect whether the column is locked or not.
When you insert the key into the ignition the BCM senses the key insertion and assumes that you want to unlock the column and drive the car. It first checks the "state" of the column. If things are working correctly the state upon key insertion would be LOCKED. If the state is locked the BCM then sends an unlock signal (voltage) to the lock motor on the wires that would cause the lock pin to be retracted. The lock motor is supposed to retract the lock pin and respond "completed" on a specific wire back to the BCM for unlock complete. If the BCM receives the completed signal it changes the "state bit" to unlocked and then allows the car to be started and driven. When the driver is ready to leave the car they turn off the key and remove it from the ignition. The BCM senses the key removal and sends a LOCK command to the lock motor on the wire that would extend the pin and lock the column. The lock motor extends the pin and then responds "completed" to the BCM on the wire for lock complete. The BCM then changes the "state bit" to LOCKED.
That is when everything works as it should. But there are many things that can cause the signaling between the BCM and lock motor to not function correctly. Battery voltage being low is one of the most common causes. Bad relays and damaged wiring and failures of the lock motor are others.
When the signaling is not completed the BCM needs to prevent the car from being driven "INCASE" the column is actually locked and it also needs to also try to recover the "state" to get things back in sync on the chance that things can be recovered.
The Column Lock Recall was forced by NHTSA not because the column locks but rather because under certain circumstances the car could be driven with the column locked. CLEARLY a safety issue... GM's solution to the problem of the column lock system failing was multi-fold. On the automatic trans cars (97 to 2000) they installed a small diameter lock plate that prevented the column from physically locking since automatics were NOT required to have the column locking system. But for the manual trans cars the Federal law prevented the replacement of the lock ring. So GM implemented a procedure where the BCM would signal the PCM to "enable fuel shutoff" in the event that the BCM found itself in a condition where it could not recover sync and was unsure of the actual "state" of the column lock. They flashed the PCM on manual trans cars to have a 2mph fuel shutoff speed stored. When signaled by the BCM to enable fuel shutoff the PCM monitors vehicle speed and at 2mph it shuts off fuel and the car stalls. ie car cannot be driven!!!!!
GM was aware of the flaws of the column lock system as early as 1998 but did nothing to correct the issue across the C5 fleet of cars until NHTSA forced the recall in Jan 2004. They did however, install the small diameter lock ring on automatics beginning in 2001 so the 2001 - 2004 automatics seldom experience the column lock symptoms.. GM chose NOT to revamp the design of the column lock system which is rooted in the BCM. This no doubt saved them untold millions of $$$$ of expense...
So the fact that the key falls out of the key cylinder or is loose enough to be removed with the engine running on the Thread Starters vehicle can result in the column locking system being unable to detect the key removal at engine shut down time thereby causing the BCM to have an incorrect state when the next start time comes. The BCM recognises the out of sync condition and raises the "pull key and wait..." message in the DIC. If the driver removes the key then the BCM will send a lock command to the lock motor to cause the column to be locked. The lock motor would hopefully lock the column and respond "completed" which would get the BCM back in sync. But because of the lack of reliability of the factory system this does NOT always happen. If the BCM cannot recover sync the BCM then sends the "enable fuel shutoff" command to the PCM. If the 2mph value is set then the car cannot be driven. This was supposed to only be the case for manual trans cars.... But unfortunately the instructions on how to handle the column lock recall service was and is complex enough/poorly written that many automatics also have the fuel shutoff set in the PCM when they should not by GM techs that were confused....
I have written copies of all the variations of the GM Column Lock Recall service and can attest to the complexity of the instructions.
My point with the above novel
is to point out that a simple thing like the key falling out can result in symptoms that one would not easily understand if they thought the key was just/simply a convenient way to get the engine to start............
On the C5 the pellet on the key is a part of the securtity (VATS) system that is intended as a theft deterrent feature. It applies to both manual and automatic trans cars.... The pellet and the cut of the key make up a somewhat unique combination that is intended to help avoid theft of the car by someone that might for example use a screw driver jammed into the key cylinder to turn the ignition switch as they attempt to steal the car. Also the key is part of the Column Lock function which is a left over Federally mandated theft deterrent system. It stems from laws made back in the 1960's where a "column locking" device was required on all manual trans cars as an "added theft deterrent" .
GM like most car manufacturers decided to utilize the same "column locking" function on both manual and automatic trans cars to simplify the build process at the factory and not have to use different components for manual vs automatic cars.
In the case of the C5 the ignition key is NOT on the column so a direct link between the key and the locking mechanism does not exist. So GM needed to be developed way to control the lock motor that locks and unlocks the column from the dash mounted ignition switch. GM chose to tie this into the Body Control Module or BCM. The way it works is that the BCM needs to keep a "state" bit to know if the column is locked or unlocked since the BCM has no physical way to detect whether the column is locked or not.
When you insert the key into the ignition the BCM senses the key insertion and assumes that you want to unlock the column and drive the car. It first checks the "state" of the column. If things are working correctly the state upon key insertion would be LOCKED. If the state is locked the BCM then sends an unlock signal (voltage) to the lock motor on the wires that would cause the lock pin to be retracted. The lock motor is supposed to retract the lock pin and respond "completed" on a specific wire back to the BCM for unlock complete. If the BCM receives the completed signal it changes the "state bit" to unlocked and then allows the car to be started and driven. When the driver is ready to leave the car they turn off the key and remove it from the ignition. The BCM senses the key removal and sends a LOCK command to the lock motor on the wire that would extend the pin and lock the column. The lock motor extends the pin and then responds "completed" to the BCM on the wire for lock complete. The BCM then changes the "state bit" to LOCKED.
That is when everything works as it should. But there are many things that can cause the signaling between the BCM and lock motor to not function correctly. Battery voltage being low is one of the most common causes. Bad relays and damaged wiring and failures of the lock motor are others.
When the signaling is not completed the BCM needs to prevent the car from being driven "INCASE" the column is actually locked and it also needs to also try to recover the "state" to get things back in sync on the chance that things can be recovered.
The Column Lock Recall was forced by NHTSA not because the column locks but rather because under certain circumstances the car could be driven with the column locked. CLEARLY a safety issue... GM's solution to the problem of the column lock system failing was multi-fold. On the automatic trans cars (97 to 2000) they installed a small diameter lock plate that prevented the column from physically locking since automatics were NOT required to have the column locking system. But for the manual trans cars the Federal law prevented the replacement of the lock ring. So GM implemented a procedure where the BCM would signal the PCM to "enable fuel shutoff" in the event that the BCM found itself in a condition where it could not recover sync and was unsure of the actual "state" of the column lock. They flashed the PCM on manual trans cars to have a 2mph fuel shutoff speed stored. When signaled by the BCM to enable fuel shutoff the PCM monitors vehicle speed and at 2mph it shuts off fuel and the car stalls. ie car cannot be driven!!!!!
GM was aware of the flaws of the column lock system as early as 1998 but did nothing to correct the issue across the C5 fleet of cars until NHTSA forced the recall in Jan 2004. They did however, install the small diameter lock ring on automatics beginning in 2001 so the 2001 - 2004 automatics seldom experience the column lock symptoms.. GM chose NOT to revamp the design of the column lock system which is rooted in the BCM. This no doubt saved them untold millions of $$$$ of expense...
So the fact that the key falls out of the key cylinder or is loose enough to be removed with the engine running on the Thread Starters vehicle can result in the column locking system being unable to detect the key removal at engine shut down time thereby causing the BCM to have an incorrect state when the next start time comes. The BCM recognises the out of sync condition and raises the "pull key and wait..." message in the DIC. If the driver removes the key then the BCM will send a lock command to the lock motor to cause the column to be locked. The lock motor would hopefully lock the column and respond "completed" which would get the BCM back in sync. But because of the lack of reliability of the factory system this does NOT always happen. If the BCM cannot recover sync the BCM then sends the "enable fuel shutoff" command to the PCM. If the 2mph value is set then the car cannot be driven. This was supposed to only be the case for manual trans cars.... But unfortunately the instructions on how to handle the column lock recall service was and is complex enough/poorly written that many automatics also have the fuel shutoff set in the PCM when they should not by GM techs that were confused....
I have written copies of all the variations of the GM Column Lock Recall service and can attest to the complexity of the instructions.
My point with the above novel
is to point out that a simple thing like the key falling out can result in symptoms that one would not easily understand if they thought the key was just/simply a convenient way to get the engine to start............
The following users liked this post:
Red Robin (08-07-2016)
08-07-2016, 01:52 AM
#19
[QUOTE=8VETTE7;1592793022]Not trying to impress anyone. Simply trying to point out that the key for the C5 and infact for MOST newer vehicles performs several functions some of which can be/are inter-related.
On the C5 the pellet on the key is a part of the securtity (VATS) system that is intended as a theft deterrent feature. It applies to both manual and automatic trans cars.... The pellet and the cut of the key make up a somewhat unique combination that is intended to help avoid theft of the car by someone that might for example use a screw driver jammed into the key cylinder to turn the ignition switch as they attempt to steal the car. Also the key is part of the Column Lock function which is a left over Federally mandated theft deterrent system. It stems from laws made back in the 1960's where a "column locking" device was required on all manual trans cars as an "added theft deterrent" .
GM like most car manufacturers decided to utilize the same "column locking" function on both manual and automatic trans cars to simplify the build process at the factory and not have to use different components for manual vs automatic cars.
In the case of the C5 the ignition key is NOT on the column so a direct link between the key and the locking mechanism does not exist. So GM needed to be developed way to control the lock motor that locks and unlocks the column from the dash mounted ignition switch. GM chose to tie this into the Body Control Module or BCM. The way it works is that the BCM needs to keep a "state" bit to know if the column is locked or unlocked since the BCM has no physical way to detect whether the column is locked or not.
When you insert the key into the ignition the BCM senses the key insertion and assumes that you want to unlock the column and drive the car. It first checks the "state" of the column. If things are working correctly the state upon key insertion would be LOCKED. If the state is locked the BCM then sends an unlock signal (voltage) to the lock motor on the wires that would cause the lock pin to be retracted. The lock motor is supposed to retract the lock pin and respond "completed" on a specific wire back to the BCM for unlock complete. If the BCM receives the completed signal it changes the "state bit" to unlocked and then allows the car to be started and driven. When the driver is ready to leave the car they turn off the key and remove it from the ignition. The BCM senses the key removal and sends a LOCK command to the lock motor on the wire that would extend the pin and lock the column. The lock motor extends the pin and then responds "completed" to the BCM on the wire for lock complete. The BCM then changes the "state bit" to LOCKED.
That is when everything works as it should. But there are many things that can cause the signaling between the BCM and lock motor to not function correctly. Battery voltage being low is one of the most common causes. Bad relays and damaged wiring and failures of the lock motor are others.
When the signaling is not completed the BCM needs to prevent the car from being driven "INCASE" the column is actually locked and it also needs to also try to recover the "state" to get things back in sync on the chance that things can be recovered.
The Column Lock Recall was forced by NHTSA not because the column locks but rather because under certain circumstances the car could be driven with the column locked. CLEARLY a safety issue... GM's solution to the problem of the column lock system failing was multi-fold. On the automatic trans cars (97 to 2000) they installed a small diameter lock plate that prevented the column from physically locking since automatics were NOT required to have the column locking system. But for the manual trans cars the Federal law prevented the replacement of the lock ring. So GM implemented a procedure where the BCM would signal the PCM to "enable fuel shutoff" in the event that the BCM found itself in a condition where it could not recover sync and was unsure of the actual "state" of the column lock. They flashed the PCM on manual trans cars to have a 2mph fuel shutoff speed stored. When signaled by the BCM to enable fuel shutoff the PCM monitors vehicle speed and at 2mph it shuts off fuel and the car stalls. ie car cannot be driven!!!!!
GM was aware of the flaws of the column lock system as early as 1998 but did nothing to correct the issue across the C5 fleet of cars until NHTSA forced the recall in Jan 2004. They did however, install the small diameter lock ring on automatics beginning in 2001 so the 2001 - 2004 automatics seldom experience the column lock symptoms.. GM chose NOT to revamp the design of the column lock system which is rooted in the BCM. This no doubt saved them untold millions of $$$$ of expense...
So the fact that the key falls out of the key cylinder or is loose enough to be removed with the engine running on the Thread Starters vehicle can result in the column locking system being unable to detect the key removal at engine shut down time thereby causing the BCM to have an incorrect state when the next start time comes. The BCM recognises the out of sync condition and raises the "pull key and wait..." message in the DIC. If the driver removes the key then the BCM will send a lock command to the lock motor to cause the column to be locked. The lock motor would hopefully lock the column and respond "completed" which would get the BCM back in sync. But because of the lack of reliability of the factory system this does NOT always happen. If the BCM cannot recover sync the BCM then sends the "enable fuel shutoff" command to the PCM. If the 2mph value is set then the car cannot be driven. This was supposed to only be the case for manual trans cars.... But unfortunately the instructions on how to handle the column lock recall service was and is complex enough/poorly written that many automatics also have the fuel shutoff set in the PCM when they should not by GM techs that were confused....
I have written copies of all the variations of the GM Column Lock Recall service and can attest to the complexity of the instructions.
My point with the above novel is to point out that a simple thing like the key falling out can result in symptoms that one would not easily understand if they thought the key was just/simply a convenient way to get the engine to start............[/QUO
Thank you for sending this to me! knowledge is power!
On the C5 the pellet on the key is a part of the securtity (VATS) system that is intended as a theft deterrent feature. It applies to both manual and automatic trans cars.... The pellet and the cut of the key make up a somewhat unique combination that is intended to help avoid theft of the car by someone that might for example use a screw driver jammed into the key cylinder to turn the ignition switch as they attempt to steal the car. Also the key is part of the Column Lock function which is a left over Federally mandated theft deterrent system. It stems from laws made back in the 1960's where a "column locking" device was required on all manual trans cars as an "added theft deterrent" .
GM like most car manufacturers decided to utilize the same "column locking" function on both manual and automatic trans cars to simplify the build process at the factory and not have to use different components for manual vs automatic cars.
In the case of the C5 the ignition key is NOT on the column so a direct link between the key and the locking mechanism does not exist. So GM needed to be developed way to control the lock motor that locks and unlocks the column from the dash mounted ignition switch. GM chose to tie this into the Body Control Module or BCM. The way it works is that the BCM needs to keep a "state" bit to know if the column is locked or unlocked since the BCM has no physical way to detect whether the column is locked or not.
When you insert the key into the ignition the BCM senses the key insertion and assumes that you want to unlock the column and drive the car. It first checks the "state" of the column. If things are working correctly the state upon key insertion would be LOCKED. If the state is locked the BCM then sends an unlock signal (voltage) to the lock motor on the wires that would cause the lock pin to be retracted. The lock motor is supposed to retract the lock pin and respond "completed" on a specific wire back to the BCM for unlock complete. If the BCM receives the completed signal it changes the "state bit" to unlocked and then allows the car to be started and driven. When the driver is ready to leave the car they turn off the key and remove it from the ignition. The BCM senses the key removal and sends a LOCK command to the lock motor on the wire that would extend the pin and lock the column. The lock motor extends the pin and then responds "completed" to the BCM on the wire for lock complete. The BCM then changes the "state bit" to LOCKED.
That is when everything works as it should. But there are many things that can cause the signaling between the BCM and lock motor to not function correctly. Battery voltage being low is one of the most common causes. Bad relays and damaged wiring and failures of the lock motor are others.
When the signaling is not completed the BCM needs to prevent the car from being driven "INCASE" the column is actually locked and it also needs to also try to recover the "state" to get things back in sync on the chance that things can be recovered.
The Column Lock Recall was forced by NHTSA not because the column locks but rather because under certain circumstances the car could be driven with the column locked. CLEARLY a safety issue... GM's solution to the problem of the column lock system failing was multi-fold. On the automatic trans cars (97 to 2000) they installed a small diameter lock plate that prevented the column from physically locking since automatics were NOT required to have the column locking system. But for the manual trans cars the Federal law prevented the replacement of the lock ring. So GM implemented a procedure where the BCM would signal the PCM to "enable fuel shutoff" in the event that the BCM found itself in a condition where it could not recover sync and was unsure of the actual "state" of the column lock. They flashed the PCM on manual trans cars to have a 2mph fuel shutoff speed stored. When signaled by the BCM to enable fuel shutoff the PCM monitors vehicle speed and at 2mph it shuts off fuel and the car stalls. ie car cannot be driven!!!!!
GM was aware of the flaws of the column lock system as early as 1998 but did nothing to correct the issue across the C5 fleet of cars until NHTSA forced the recall in Jan 2004. They did however, install the small diameter lock ring on automatics beginning in 2001 so the 2001 - 2004 automatics seldom experience the column lock symptoms.. GM chose NOT to revamp the design of the column lock system which is rooted in the BCM. This no doubt saved them untold millions of $$$$ of expense...
So the fact that the key falls out of the key cylinder or is loose enough to be removed with the engine running on the Thread Starters vehicle can result in the column locking system being unable to detect the key removal at engine shut down time thereby causing the BCM to have an incorrect state when the next start time comes. The BCM recognises the out of sync condition and raises the "pull key and wait..." message in the DIC. If the driver removes the key then the BCM will send a lock command to the lock motor to cause the column to be locked. The lock motor would hopefully lock the column and respond "completed" which would get the BCM back in sync. But because of the lack of reliability of the factory system this does NOT always happen. If the BCM cannot recover sync the BCM then sends the "enable fuel shutoff" command to the PCM. If the 2mph value is set then the car cannot be driven. This was supposed to only be the case for manual trans cars.... But unfortunately the instructions on how to handle the column lock recall service was and is complex enough/poorly written that many automatics also have the fuel shutoff set in the PCM when they should not by GM techs that were confused....
I have written copies of all the variations of the GM Column Lock Recall service and can attest to the complexity of the instructions.
My point with the above novel
is to point out that a simple thing like the key falling out can result in symptoms that one would not easily understand if they thought the key was just/simply a convenient way to get the engine to start............[/QUOThank you for sending this to me! knowledge is power!
08-07-2016, 10:48 PM
#20
I would start with getting a new key. If you do not have a backup key that is in reasonibly good shape then you will need to go to a GM dealership and have them cut you a new key from the VIN. I would check around and see what they want and personally would not pay more than about $30 or so for the key. You might want to consider getting 2 keys.
Once you have a good key you need to get a replacement key cylinder. Here is Delco cylinder on Amazon for around $72:
https://www.amazon.com/ACDelco-D1473.../dp/B000EQVYFK
You will then need to take the new key and cylinder to a local locksmith and have them code the cylinder to the key. I've seen this cost in the $15 to $25 range.
With the key and now coded cylinder you have to remove the worn out cylinder and install the replacement.
The toughest part of this procedure is removing the center console. Here is a link that details how to do that with pictures. Follow the steps through 3G to remove the center console:
http://www.vetteessentials.com/instr...zel_howto.html
With the radio bezel now out of the way you will see the key cylinder and the wire for the VATS function. Here is how to remove and reinstall the key cylinder from my shop manual:
Attachment 48007111
Attachment 48007112
Attachment 48007113
Once you have a good key you need to get a replacement key cylinder. Here is Delco cylinder on Amazon for around $72:
https://www.amazon.com/ACDelco-D1473.../dp/B000EQVYFK
You will then need to take the new key and cylinder to a local locksmith and have them code the cylinder to the key. I've seen this cost in the $15 to $25 range.
With the key and now coded cylinder you have to remove the worn out cylinder and install the replacement.
The toughest part of this procedure is removing the center console. Here is a link that details how to do that with pictures. Follow the steps through 3G to remove the center console:
http://www.vetteessentials.com/instr...zel_howto.html
With the radio bezel now out of the way you will see the key cylinder and the wire for the VATS function. Here is how to remove and reinstall the key cylinder from my shop manual:
Attachment 48007111
Attachment 48007112
Attachment 48007113