Sorry folks, I have spent a couple hours reading the archives, but I didn't really see answers to my question.

Will just switching the K Harness with the CLB fix the problem? Here is my situation:

I have a beautiful 03 vert standard 6 spd. I got the "Service Column Lock" message and "pull key" message Sunday, BUT my column is "not" locked. However the 2 mph limit works great. So, from the guidence of archives:

I have ordered a CLB and hope to get it today.
I disconnected the negative battery terminal for 10 minutes, but the messages still come back.
I don't have have the purple splice in the passenger footwell.
I do have the K Harness installed.

So, can a failed K Harness be the cause of the false message?

I guess what is confusing me are the messages w/o the column locking.

Thanks ahead for your much appreciated guidence.

Beary

 

Beary, there are many on the Forum far more knowledgeable than I about your situation and I am sure you will be hearing from them. But what it sounds like to me is that your locking arrangement was disabled as part of one of the recalls, and the "K" harness installed, probably at the same time. Installation of your CLB in place of the harness should get you back on the road. If not, the Forum has more options for you to examine, 'tho you may have to do some hunting for them. Good luck.

 

Thanks rboineau

I'm just trying to have a list of things to do if the CLB doesn't work. But you are right, I will ask again if the CLB doesn't work and I am still researching the problem.

Beary

 

Start by checking the battery. A weak or bad battery or loose or corroded battery connections is the single most common cause of the column lock symptoms.

Using a digital voltmeter (DMM) check the voltage directly across the battery posts with NO KEY in the ignition ( or prefferably with the neg battery cable disconnected). Needs to be a minimum of 12.5 volts for the column lock electronics to function properly. Dash gages CANNOT tell you the state of health of the battery. With engine running the voltage is the output voltage of the alternator. Nice that the alternator is charging but the CL electronics run LONG before the car starts. Key on and engine off and there are many electrical circuits loading the battery so that reading is worthless.

If the voltage is near or less than 12.5 volts you need to try charging the battery with a battery tender style charger that floats the charge when the battery is fully charged. A good battery at full charge will measure 12.6 to 12.9 volts. Once fully charged leave the neg battery cable off for at least overnight. If the voltage is back near 12.5 the following morning then replace the battery as it doesn't hold a charge with no load attached.

Once any battery issue is corrected you need to clear the codes and see what happens. Easiest way to clear codes is disconnect the neg battery cable for at least 10 minutes.

Another potential cause is the K Harness may have failed. You can determine if that is the cause by disconnecting BOTH ends of the K Harness and plugging the male connector from the lock motor (wires appear to go up into the column) into the female connector that is attached to the bottom of the dash. Clear the codes again and see what happens. If there is still a problem there are a few more possible causes. One is a blown fuse. Check all of the following fuses in the passenger footwell fuse box: 9, 13, 19, 22, 23, 25, 47, and 50. Replace any that may have blown.

Last item is the CL relay. In the passenger footwell there is a relay to the left of the fuse box and above the BCM ( silver box) that has 2 orange, 1 white 1 green and 1 purple wire going into the wiring base. That relay has been known to fail so check it.

 

Ah, I read that before but forgot it, thanks. I can try that if my CLB hasn't arived yet.

Beary

 

A CLB will work once properly installed and assuming the battery is good. Two things will cause the problems to return once a CLB is installed:

1) The CLB fails. Could happen but extremely unlikely that it will.

2) The battery goes low (12.5 volts or less.) Batterys do fail so that is a definite possibility. The CLB replaces the function that would normally be provided by the Lock Motor. When the BCM senses you inserting the key it sends an UNLOCK signal to the lock motor. It is supposed to unlock (retract the lock pin) and then send a completed signal back to the BCM. The BCM expects that completed signal back and if it does NOT receive it the BCM sends an "enable fuel shutoff" signal to the PCM. If you try and drive the car in this situation the PCM will shutoff fuel at 2mph. Installing a CLB entails unlocking the column and then disconnecting the lock motor male connector from the female connector behind the drivers knee bolster and then plugging the male connector of the CLB into the female connector. The BCM then is sending its lock and unlock signals to the CLB. The CLB is an electronic relay so once it receives a signal from the BCM it turns that signal around back to the BCM as a completed signal. Basically fooling the BCM into thinking the requested action was successfully completed. Since the lock motor is disconnected the column will never again lock but the BCM has no clue that has happened.

Only way to insure that the fuel shutoff will never hit you is to have the fuel shutoff speed programmed to a large number like 200 or 255 (max). Then even if the CLB fails the car will still be driveable up to the fuel shutoff speed. You do get error messages in the DIC but the car is driveable. Need to find a tuner with either HP Tuners or EFI Live tuning software. No other tuning tool can set the fuel shutoff speed individually. Cost should be around $100 to do that.

 

Thanks, I will double check the battery voltage again, but this is what I was not sure about. I can hear the motor retract the lock pin and I can thankfully steer the car at a blistering 1 mph up hill into the garage. Why doesn't the BCM receive the signal the pin is retracted? I am assuming (hoping) the K Harness prevents that signal back to BCM, but I thought the part that failed on a K harness was the relay. Does the failed relay block the signal back to the BCM? I guess it can.

One other question I have not read anywhere is has anyone tried removing the locking plate on the 6spd?

Beary

 

You really cannot "remove" the lock plate. It serves several functions other than just for the column lock system. It also provides the turn signal cancellation function as you turn a corner and provides a spacing function for the other items "stacked" on the column. You CAN replace the full size one with the smaller diameter one that is used on the automatic cars. However there is significant disassembly of the column to do that. One of the variations of the GM Column Lock service (04006C) actually does that. If your column does not lock with no key in the ignition then your car may have variation 04006C done to it. Most folk just use the CLB to prevent the column from locking as it is a lot more reliable than leaving the lock motor operating ( lock motors do fail) and less expensive than the lock plate/ring replacement option.

As far as why you are getting the fuel shutoff, it is the result of the BCM not receiving the "completed" signal it expects. Exactly why is the question of the minute. Battery? K harness? Fuses? CL relay? Micro switch in the lock motor? You simply have to investigate and see which one (or possibly combination) is the cause.

 

Thanks, that settles that.

Great info thanks. I will let you know. It is amazing how something with a simple purpose could be so complicated in function. What a mess.

Beary

 

Update, it was the K hanress.

Thanks to all who helped me through this mess. Not sure what the total cost would have been to have the vette towed to the dealer and have them work on it, but with help from you guys, it only cost me $50 for a new CLB. My CPA wife thanks you as well.

Love the car, now if I just attack that leaking butt problem, but that is another thread for another weekend.

Thanks again all.

Beary

 

THANK YOU for posting the outcome Beary. Thats helps us all.