INTERMITTENT NO START CAUSED BY ANTI-THEFT SYSTEM

INTERMITTENT NO-START CONDITION CAUSED BY THE VEHICLE ANTI-THEFT SYS. (VATS/PASS KEY) Revised for new parts and additional troubleshooting information.

VEHICLES AFFECTED: 1986-88 Y AND 1988 PONTIAC F-GTA ONLY (DIAGNOSTICS)

Some 1986-88 Corvettes and/or 1988 Pontiac Firebird GTAs have been returned because of an intermittent no-start condition. In some cases the vehicle may start after waiting for approximately 4 minutes.

This condition could be caused by a damaged ignition lock cylinder or damaged resistor pellet inside the ignition key. This causes the VATS/Pass Key module to sense an intermittent resistance value or open circuit at the pellet, which then shuts the system down for approximately 4 minutes. (Refer to the 1988 Corvette Shop Manual pages 8A-133-8 through 8A-133-14 or the 1988 Pontiac Firebird Shop Manual pages 8A -133-0 through 8A-133-6 for a more detailed description of the system)

If a vehicle is returned to the dealership with an intermittent no start condition caused by the VATS/Pass Key system, the following items can be checked in addition to the diagnostics in the service manual.

1). The braided ground strap connected between the left hand rear of the engine (G104) and the frame next to the battery (G101) should be fastened tightly. Lack of a good ground for the VATS/Pass Key system could cause an intermittent no start.

2). The resistor pellet in the ignition key should be visually checked to see if there is any foreign material (plastic flash, dirt, etc.) covering either side of the metal contact.

3). The metal contacts inside the ignition lock cylinder (located in the steering column) should be clean and parallel to each other. If these contacts are bent or damaged, they will not make a good contact with the pellet in the key resulting in a no-start condition.

If the contacts are damaged, replace the ignition lock cylinder with a new replacement lock cylinder, P/N 26009609, which is available from GM PARTS

NOTICE: WHEN A LOCK CYLINDER IS REPLACED THERE IS NO NEED TO ALSO REPLACE THE VATS/PASS KEY MODULE.

4). If a vehicle has a history of intermittent no starts and repeated diagnosis can not repair the vehicle, the ignition lock cylinder should be replaced with a new lock cylinder, P/N 26009609.

Parts are currently available from GM PARTS.

New keys (3) of the proper code should be ordered when replacing the lock cylinder. Check the old key to obtain the proper code, using the (J35628) VATS/Pass Key Interrogator.

Use applicable labor code.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.