SERVICE ENGINE SOON LIGHT PROCEDURE/DIAG. REPLACE TPS

SUBJECT: SERVICE ENGINE SOON LIGHT (CODE 22) PROCEDURE/DIAGNOSTICS REPLACE TPS

MODELS/YEARS: 1991 CUSTOM CRUISER, BRAVADA, AND SILHOUETTE

This bulletin pertains to the 5.0L (VIN E) engine for The Custom Cruiser, 4.3L (VIN Z) engine for the Bravada, and 3.1L (VIN D) engine for the Silhouette.

CONDITION: Some owners of the above vehicles may comment on a Service Engine Soon Light, Code 22, Throttle Position Sensor low. Additional comments may include poor idle quality. These conditions may be more prevalent after initial startup.

CAUSE: The above concerns may result from an intermittent electrical contact inside the Throttle Position Sensor (TPS).

CORRECTION: If any of the subject conditions are found, complete the following procedure:

1. Perform the normal diagnostics per Section 6E of the service manual.

2. Check TPS/ECM connectors per the article in May 1988 Service Guild on Page 73.

3. If no problems are found using the normal 6E2 diagnostics or the Service Guild article mentioned above, replace the TPS with a NEW TPS kit, P/N 17112679, currently available from GMSPO, per the procedure in Section 6E2 of the service manual. The new TPS will have a yellow dot at the connector area for easier identification. The kit contains a sensor, a gasket and two screws with thread lock.

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.