Bulletin No.: PIC6522
Published date: 10/5/2023

Preliminary Information
PIC6522 Diagnostic Tip - Steering Column Lock System
Models
Brand:
Chevrolet

Model:
Corvette

Model Years:
1997 - 2004

VIN:
from
All

Engine:

to
All

All

Transmissions:
All

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Involved
Region or United States
Country
Some customers may comment about a DIC message that states either "Service Column Lock" or "Pull
Key, Wait 10 Seconds". They may also have a concern where the vehicle will not crank, or when put into
Condition
gear the vehicle's engine may run rough or stall. Vehicle speed may also be limited to approximately 3
mph.
Concern The cause of these concerns may be a malfunctioning Steering Column Lock system.

Correction:
The cause of these symptoms may vary wildly from vehicle to vehicle. The purpose of this PIC is to assist the
dealership technician in understanding the operation of this column lock system, it's many changes throughout
the years, and how to correctly go about diagnosing it when it has an issue.
The steering column lock system was rst used on the 1997 Corvette. This was the rst year of the brand new
C5 generation. The system would physically lock the steering wheel and prevent it from being turned when the
ignition was in the o position. This helped to prevent a vehicle from being stolen. Once the ignition was turned
on, the column unlocked, and it was then free to rotate. This system employed the use of a steering column lock
plate, both a key-in, and key-out microswitch, the BCM, and a column lock motor or actuator. This motor
extended and retracted a pintle. This would cause an interference with the column lock plate that was mounted
on the steering column. When the pintle was extended, this prevented column rotation. When the pintle was
retracted, the column was free to rotate.
Many misconceptions exist around the separate publications, special policy and bulletins regarding the Steering
Column Lock system. There are many questions surrounding the operation, diagnosis, repairs, and the di erent
revisions to each document. This PI is intended to help clear up those misconceptions. As always, dealership
technicians are to check IVH for any open campaigns on the vehicle in question before beginning diagnosis.
Bulletin 01-02-35-008: This Service Bulletin only applies to all 1997 Corvettes, but only some 1998 and 2000
Corvettes built within a speci ed VIN range. This bulletin applies to vehicles that are NOT included in Customer
Satisfaction Campaign 01044A Corvette Electronic Column Lock.
01044A: This Customer Satisfaction document expired July 1, 2003. It covered a condition in which the electronic
column lock may not function as intended. The condition could result in the failure of the steering column to
unlock during initial key-in and start-up. Should the column fail to unlock, the engine will stop running if the
vehicle starts to move.
04006: This Bulletin covered a condition where the fuel shut o may not occur and the vehicle can be accelerated
while the steering system is locked. The x was to mechanically disable the electronic column lock by removing
the column lock plate on certain vehicles listed. Due to tool and part availability this bulletin was released in 3
phases:
Rev. A: Additional vehicles have been added to the population. This bulletin does not include a service procedure
for 97 Manuals and export Automatics, or 98 Manuals and export Automatics built through May 25, 1998.
Rev. B: Was revised to include 97 Manuals and export Automatics and 98 Manuals and export Automatics built

through May 25, 1998.
Rev. C: The service procedure for U.S. vehicles equipped with a manual transmission has been revised to remove
the lock plate. Important: Changes in federal requirements allowed the release of revision C, however, due to the
timing of the release; U.S. vehicles equipped with a manual transmission and serviced under previous versions of
04006 will still have the lock plate in place.
05081: This Special Policy Adjustment expired February 8, 2006. It covered 1997 - 2004 Chevrolet Corvettes
equipped with a manual transmission (MM6 / M12); 1997 - 2000 Chevrolet Export Corvettes equipped with an
automatic transmission; and 2001 - 2004 Chevrolet European Export Corvettes equipped with an automatic
transmission that may have a condition where the column lock may fail to unlock the steering column when the
vehicle is started and 04006C was already completed.
Due to the multiple publications, various release dates of each and changes in the service procedures, some
questions may arise as to whether or not a document was completed properly. In particular, 04006C allowed the
removal of the lock plate from U.S. vehicles equipped with manual transmissions. Prior to the release of version
C, lock plate removal was not allowed, due to federal requirements in place at that time.
It is OK to have a manual equipped U.S. vehicle that has the lock plate in place, if it was serviced under a previous
release of 04006. The presence of the lock plate in no way indicates incorrect procedures were performed. The
customer and the dealer have the option of installing the cam orientation plate in place of the lock plate, but this
is not a warranty repair, nor will it correct a "Service Column Lock" or "Pull Key, Wait 10 Seconds" message.

Updated Diagnostic Aid The following information has been complied over the years through the Technical Assistance Center (TAC) and it
has been presented here to assist the eld with diagnosing this system on US vehicles only. While this section
has many tips for diagnosing the Service Column Lock message, it was written to cover a concern of that message
being displayed immediately following 01044, 04006, or 05081 only. If a dealer is experiencing a Service Column
Lock message and did not just complete one of those documents, then the diagnostic charts published in SI
should be referenced. Low voltage is still a large contributor to these DIC messages, especially since this message
is often seen as cars are brought out of seasonal storage, which is the most opportune time to experience low
system voltages. Therefore, technicians should:
1. Ensure the latest revision of recall 04006 has been performed. This action instructs the dealership to remove
the lock plate. Special Policy Bulletin 05081 expired on Feb 28, 2008 and is no longer in e ect. Try to rotate the
steering wheel with the ignition o ; if the steering wheel will not move or appears locked, the column lock plate
most likely has not been removed and recall 04006 should be completed. Since the recall has been closed, the
repair will require claim pre-authorization.
Important: The remainder of this PI is written and should only be used for the condition and the models
described above, in which a "Service Column Lock" message appears immediately following, or very shortly after
completion of the campaign/special policy mentioned. Most vehicles seeking service today will likely have already
had the applicable campaign/special policy completed months, or even years prior. Therefore, the PI information
contained here would not apply.
Note: Published Service Information should be followed for conditions not speci cally described above in this PI.
2. Con rm the battery can pass a battery load test and also make sure that it is fully charged. Once those have
been done, disconnect and reconnect the battery to see if the concern is resolved.
3. Inspect Grounds G201 and G202 at the Driver and Passenger side 'A' pillars.
4. If a concern with the grounds is not found, remove the column lock relay and jumper harness that was installed
as part of the campaign. Install a new relay and jumper (part number 19244028). As of November 2009, the relay
in this harness is new, and it was designed to cancel out electrical interference that has been suspected of
causing false messages. This harness is designed to electrically duplicate the lock/unlock signal from the column
lock motor.
NOTE: It is important to make sure the column lock plate is removed before installing this new relay.
5. If the concern is not resolved with the new harness, then inspect the 4 digit date code that is located on the
bottom of the electronic column lock (ECL) motor. The rst character of the date code is the month, second two
numbers are the day, and the fourth digit is the year. (Example: 8041 = August 4th, 2001. If a letter is used for the
rst character, this is to indicate the months of October, November, or December. Example N041 = November
4th, 2001)
* If the date code of the ECL motor is before January 01, 2003, replace the electronic column lock motor and
reinstall the original connector, without the relay or jumper harness installed. (Note: Do not remove the Cam
Orientation Plate)

* If the date code of the motor is after January 01, 2003, only the new jumper harness will be required. If the
concern is still occurring after following all information above, then follow published diagnostics. (Note: Do not
remove the Cam Orientation Plate)
* If the concern is resolved, the harness and relay should be replaced with the latest part number available, as
improvements have been made in the later parts. If it returns after the harness and relay were replaced with new
parts, they can be entirely removed, and left o the vehicle permanently, as their presence was not required to
meet Federal Motor Vehicle Safety Standards (FMVSS) requirements.
Important Note: There have been a few questions regarding which decade (1990's, 2000's, 2010's) that the ECL
motor was produced in. A review of the parts history has proven that the date code on current / new CCA parts,
are all within the 2010's. The age of a part should never be assumed based on the appearance or condition of the
packaging it is in.
Note: DO NOT advise a dealer to request RFI through Partech for a di erent date code or vendor stamping!
To decipher the decade on the ECL motor that is currently in the vehicle, you will need the date code and the part
number that is stamped on it. Use the following chart to determine the date code of the old/original ECL motor.
6. If the concern is still occurring with the harness and relay removed, the dealer should begin to follow SI
diagnostics for the condition the vehicle is exhibiting, i.e. Column Won't Lock OR Column Won't Unlock. Keep in
mind that if 04006C was performed, the steering wheel will not lock on U.S. vehicles. The (Electronic Column
Lock) ECL actuator should still be moving to a locked and an unlocked position, appropriately, regardless of
whether or not the relay and harness are in the vehicle.
Note: The harness and relay installed during 04006 or 05081 supplies a locked and unlocked signal to the BCM; it
does NOT actually inhibit actuator operation.

If a dealership technician is directed to regular service information for diagnosing this system, It is suggested that
the technician rst check the operation of the column lock motor, using the Tech 2 Special Function command to
see if the motor will operate. If it does not, a common reason for this is because the OEM column lock relay (NOT
the additional relay that was added as part of the recall) is simply no longer operational. These were mechanical
relays and they may be as many as 25+ years old at this time. The contacts may have been worn out. Being
certain to select the correct relay, as there are several of them in a line, place your ngers on the relay, located
under the glovebox, and rotate the ignition switch on and o . Attempt to feel the operation of this relay when it
clicks. If it is not working, continue with diagnosis. As always, feel free to call TAC for assistance once the
applicable measurements have been recorded.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is
resolved without completing every step, the remaining steps do not need to be performed.

Version History
Version
Modi ed

1
10/05/2023 - Created on.

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