column lock
Melting Slicks
Joined: Sep 2008
Posts: 3,127
Likes: 799
From: Espanola New Mexico
If a CLB has been done your steering wheel should not lock when the car is turned off and key removed, the column locking while driving is a myth, but GM did put in the 2 mph fuel cut off just in case.
Melting Slicks
Joined: Feb 2001
Posts: 2,800
Likes: 356
From: Northville, MI
However, if your car has every been to the dealer since about 2004 the 2 mph shutoff was updated to the PCM. If so always check your battery voltage with the car off and not driven. If the battery is below 12.5V then the 2 mph shutoff can kick in at any time. Years ago, before the LMC5 came out I had the early CLB in my Vette and one day I was getting ready to go to an event and the car would start but would not let you drive it. After learning about the battery problems, I check my voltage and it was 12.3V, new battery and the problem went away. Eventually had the shutoff raised from 2 mph to 256 mph and added the LMC5 and never had a problem since even when I forgot to put the battery tender on and 7 weeks later tried to start it....battery was down to 10.4V but recharged it and have been running ever since--I am now more serious about using the battery tender when not driving the Corvette for several weeks.
Le Mans Master
Joined: Feb 2012
Posts: 6,644
Likes: 479
From: OK
8vette7
That can happen ( column locks while driving) if you have a GM K Harness installed in a manual trans 2001 - 2004 and still have the full size lock ring and the GM K Harness fails.
Both with and without the GM K Harness installed the column lock relay (in the passenger footwell) puts 12V on the lock motor in the "pin retract" direction once the car starts so the column will not lock while in motion. That's the purpose of the purple wire in the CL relay. In the 2001 - 2004 the CL relay was shipped with the purple wire and SPDT CL Relay. On the 1999 and 2000 manual trans, the recall service modifies the SPST CL Relay that was factory installed by replacing the SPST relay with a SPDT relay and altering the wiring on the BCM to the CL Relay. Before 1999 there was no Column Lock Relay. The lock motor was directly controlled by the BCM without an extra relay.
If the GM K Harness fails, then some signals can fail to get to the lock motor. So a problem with the lock motor itself can result in the column locking at any time. If you read the GM recall procedures for the manual trans C5 they DO NOT call for a GM K Harness to be installed. However i have helped several people with manual trans cars that DID have a Gm K Harness installed. I am guessing that the Column Lock Recall service was incorrectly done by who ever did it on your car if they in fact installed a GM K Harness in your 6 speed 01.
The other possibility is that there is no GM K Harness and the column lock relay has partially failed and that would most likely be due to a battery low voltage condition or loose or corroded battery cables. If the CL relay failed to apply 12 Volts to the purple wire and a problem with the lock motor occurred, the column could lock at any time. There will be no fuel shutoff if the column locks after the car has been started and the column unexpectedly locks after having been unlocked. The fuel shutoff logic that the BCM executes (sends a "enable fuel shutoff" signal to the PCM) is only executed if the column state cannot be determined by the BCM at startup after issueing an UNLOCK command. The BCM determines column lock state by sending Lock and Unlock signals and expecting to receive "completed" signals back to those lock and unlock signals. If the completed signals are not received the BCM assumes the worst case, that the column is locked when it should not be, and signals the PCM accordingly.
This might be worth reporting to NHTSA and to GM Customer Service if no other modifications have ever been made by you or previous owners to the column lock system.
As has already been stated, get the column unlocked and get your self a CLB or LMC5... Both devices require the column to be UNLOCKED before they are installed and both effectively disconnect power to the lock motor so that the column should never ever be able to lock again.
That can happen ( column locks while driving) if you have a GM K Harness installed in a manual trans 2001 - 2004 and still have the full size lock ring and the GM K Harness fails.
Both with and without the GM K Harness installed the column lock relay (in the passenger footwell) puts 12V on the lock motor in the "pin retract" direction once the car starts so the column will not lock while in motion. That's the purpose of the purple wire in the CL relay. In the 2001 - 2004 the CL relay was shipped with the purple wire and SPDT CL Relay. On the 1999 and 2000 manual trans, the recall service modifies the SPST CL Relay that was factory installed by replacing the SPST relay with a SPDT relay and altering the wiring on the BCM to the CL Relay. Before 1999 there was no Column Lock Relay. The lock motor was directly controlled by the BCM without an extra relay.
If the GM K Harness fails, then some signals can fail to get to the lock motor. So a problem with the lock motor itself can result in the column locking at any time. If you read the GM recall procedures for the manual trans C5 they DO NOT call for a GM K Harness to be installed. However i have helped several people with manual trans cars that DID have a Gm K Harness installed. I am guessing that the Column Lock Recall service was incorrectly done by who ever did it on your car if they in fact installed a GM K Harness in your 6 speed 01.
The other possibility is that there is no GM K Harness and the column lock relay has partially failed and that would most likely be due to a battery low voltage condition or loose or corroded battery cables. If the CL relay failed to apply 12 Volts to the purple wire and a problem with the lock motor occurred, the column could lock at any time. There will be no fuel shutoff if the column locks after the car has been started and the column unexpectedly locks after having been unlocked. The fuel shutoff logic that the BCM executes (sends a "enable fuel shutoff" signal to the PCM) is only executed if the column state cannot be determined by the BCM at startup after issueing an UNLOCK command. The BCM determines column lock state by sending Lock and Unlock signals and expecting to receive "completed" signals back to those lock and unlock signals. If the completed signals are not received the BCM assumes the worst case, that the column is locked when it should not be, and signals the PCM accordingly.
This might be worth reporting to NHTSA and to GM Customer Service if no other modifications have ever been made by you or previous owners to the column lock system.
As has already been stated, get the column unlocked and get your self a CLB or LMC5... Both devices require the column to be UNLOCKED before they are installed and both effectively disconnect power to the lock motor so that the column should never ever be able to lock again.
