Failed steering-column locks are a common problem on Fifth-generation Corvettes. In addition to being annoying, this mechanical glitch can, under the right circumstances, prove downright dangerous.
Editor's note: This month's issue was supposed to contain the final installment of our "C5 on a Shoestring" series. Unfortunately, a minor accident sidelined the car shortly before press time, making it impossible to perform any post-modification performance testing. We hope to have that story for you next month, but in the meantime, we've decided to address another topic of importance to C5 owners everywhere.
If you own a C5 Corvette, it's entirely possible that you've found yourself immobilized by a hopelessly locked steering wheel, a "Service Steering Column Lock" message glowing ominously on the instrument panel. The problem lies in the car's electro-mechanical steering lock, which was developed when the ignition switch was moved from the steering column to the dash for the Fifth-generation model. Many C5 owners complained that when starting their C5, the lock wouldn't disengage.
Here's how the system is supposed to work: When the ignition key is removed, the steering wheel is locked by an electrical motor that prevents it from turning. When the vehicle is restarted, the motor unlocks the steering. This arrangement took the place of the old ignition switch/lock assembly, theoretically providing the same theft-deterrent capabilities of the previous design.
Accessing the electro-mechanical lock motor and performing the repair should take less than one hour. Start by removing the driver-side sill plate; it simply snaps out. This makes it easier to get the knee bolster out on some Corvettes.
There are two conditions that can inhibit steering. The first is when the steering fails to unlock when the vehicle is started. The fuel supply should shut off in this case, preventing the vehicle from being driven. But if the voltage to the PCM is interrupted, it's possible that the fuel shut-off may not occur, allowing the car to be driven with the steering locked. The second situation occurs if the lock pin doesn't withdraw fully, allowing contact between the pin and lock plate. For obvious reasons, either one of these conditions could have dire consequences.
On February 10, 2004, Chevrolet issued a recall (No. 04006B) of 127,000 C5s to fix steering-column locks that could fail in the locked mode. Dealers disabled the column locks in automatic cars and installed a column-lock bypass. In manual C5s, the PCM was simply reprogrammed to remove the lock feature. But many Corvette owners with manual transmissions still experienced the problem after the recall was performed.
Nearly two years later, on February 8, 2006, Chevy issued a second recall (No. 04006C). It stated, "Dealers are to remove the column lock plate on U.S. and Canadian vehicles equipped with an automatic transmission and U.S. vehicles equipped with a manual transmission. After the service correction, the steering column will no longer lock when the key is removed." This recall applies to the following models:
Now you can begin to remove the knee bolster. Using a flathead screwdriver, pry out the bottom of the fog lamp/trunk-release switch. Once it pops out, disconnect the wiring harness attached to the switch. Inside this cavity is a screw you'll need to remove.
* '97-'04 Corvettes equipped with a manual transmission
* '97-'00 Corvettes equipped with an automatic transmission
* '01-'04 Corvettes equipped with an automatic transmission (European export vehicles only)
If your Corvette falls into one of these categories, you should have the recall performed as soon as possible.
If your steering wheel is already locked, there are a few tricks you can try to temporarily resolve the problem. First, remove the clamshell around the steering column and tap on the lock motor while turning the ignition key to the run position. Some owners have also had luck getting their steering unlocked by aggressively turning the wheel back and forth, forcing the column to unlock. Others have reported that simply turning on the air-conditioning in hot weather allows the lock to cool and disengage.
If, for whatever reason, you choose not to take your Corvette to the dealer for the repair, you can obtain a steering-lock bypass kit-we chose the Column Lock Simulator Kit (PN 618-144) from Mid America Motorworks-and do the work yourself in about an hour. Consider the job preventive maintenance, as the electro-mechanical lock motor must be free and functioning properly in order for you to install the kit. Remember, with few exceptions, there are two kinds of C5 Corvettes: the ones that have a lock-motor problem and the ones that will.