Steering Column Lock
Thread Starter
5th Gear
Joined: Sep 2017
Posts: 5
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Steering Column Lock
99 Vette started showing this error yesterday. I checked the post and looked at the BCM. Looks like the recall parts were installed already. My column is not locking even with the key removed. Car will not accelerate over 2 mph. Is there a fix before I tow it to the dealership?
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
LMC5 and do the "brown wire mod described on page 2 of the install instructions as optional".
www.complianceparts.com
www.complianceparts.com
Thread Starter
5th Gear
Joined: Sep 2017
Posts: 5
Likes: 0
Service Column Lock
I wasn't sure if a LMC5 would work if it already had the recall parts on it. The car is a garage queen and only has 27,000 original miles on it so I didn't know that the recall parts would have failed so quickly. After reading all of the post and seeing the many different possibilities from low battery to ignition switch or pellet key malfunctions, I was ready to tow it to my local dealership. I've ordered the LMC5 and will post the results after I get it installed. Thank you for your help!
Thread Starter
5th Gear
Joined: Sep 2017
Posts: 5
Likes: 0
Thanks for the help. I actually took the battery out and had it tested. Readings were 12.7 volts. After I reinstalled it I let it trickle charge to 100%. Still getting error. Hopefully the bypass module will do the trick. It's great knowing I have people like you out there to willing to give me advice. I'm very appreciative.
Thread Starter
5th Gear
Joined: Sep 2017
Posts: 5
Likes: 0
Still having issues after LMC5 installation
Several other possibilities that could cause your symptoms.
If a GM K Harness was installed it could have fried due to low battery voltage:
This would prevent the column lock system from operating correctly.
The lock motor could be hung up and not responding correctly to the BCM lock/unlock commands. Even though the column does not physically lock the BCM continues to send lock and unlock commands to the lock motor and expects back responses to every command it sends. Lack of a response causes the BCM to "assume" the column may be locked when it should be unlocked and therefore request the 2mph fuel shutoff be enabled by the PCM, This is intended to prevent an inattentive driver from trying to drive a car with a possibly locked column.
Fuse #23 could be blown.
Column Lock Relay (a separate relay from the GM K Harness relay) could be hung up or fried.
ALL of these conditions except fuse 23 (IP Fuse Box) are overcome by the LMC5 which installs at the BCM and abandons all factory and recall wiring down stream of the BCM.
The LMC5 is connected in place of the lock motor and from that point on receives the BCM commands and responds back to those commands fooling the BCM into thinking the column lock system is operating correctly. The BCM has no direct knowledge of whether the column is physically locked or not and relies on a command response protocol to keep track of the state of the column based on its commands. For this reason it is easy for the BCM to get out of sync with the actual state.
If a GM K Harness was installed it could have fried due to low battery voltage:
This would prevent the column lock system from operating correctly.
The lock motor could be hung up and not responding correctly to the BCM lock/unlock commands. Even though the column does not physically lock the BCM continues to send lock and unlock commands to the lock motor and expects back responses to every command it sends. Lack of a response causes the BCM to "assume" the column may be locked when it should be unlocked and therefore request the 2mph fuel shutoff be enabled by the PCM, This is intended to prevent an inattentive driver from trying to drive a car with a possibly locked column.
Fuse #23 could be blown.
Column Lock Relay (a separate relay from the GM K Harness relay) could be hung up or fried.
ALL of these conditions except fuse 23 (IP Fuse Box) are overcome by the LMC5 which installs at the BCM and abandons all factory and recall wiring down stream of the BCM.
The LMC5 is connected in place of the lock motor and from that point on receives the BCM commands and responds back to those commands fooling the BCM into thinking the column lock system is operating correctly. The BCM has no direct knowledge of whether the column is physically locked or not and relies on a command response protocol to keep track of the state of the column based on its commands. For this reason it is easy for the BCM to get out of sync with the actual state.
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