TPS - MIL ON/Code 22 Set/Driveability Concerns

91chevy23

Number: 91-357A-6E

Section: 6E

Date: Oct. 1991

Corporate Bulletin No.: 136514R

ASE NO.: A8


Subject: SERVICE ENGINE SOON LIGHT (CODE 22)


Model and Year: 1991 CAPRICE AND CAMARO
1991 ALL TRUCKS WITH 2.8L/4.3L, 5.0L/5.7L
AND 7.4L TBI ENGINES ONLY
1991 LUMINA (APV) WITH 3.1L TBI ENGINE ONLY


THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-157A-6E, DATED SEPTEMBER 1991. THE BULLETIN NUMBER HAS BEEN CORRECTED. ALL COPIES OF 91-157A-6E SHOULD BE DISCARDED.

PLANT VIN BREAKPOINT

SHREVEPORT 1GCCS14ZLM8177329

MORAINE 1GNCS13ZLM2211006

PONTIAC 1GCCT14Z5M0149156

This bulletin pertains to the 5.0L and 5.7L engine for passenger cars and 2.8L, 4.3L/3.1L, 5.0L/5.7L and 7.4L engines for light duty trucks TBI only.

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 no upshift to 4th gear, no TCC, harsh transmission shifts, or 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 Dealer Service Bulletin No. 91-106-6E, dated November 1990.

3. If no problems are found using the normal 6E diagnostics or the bulletin, replace the TPS with a new TPS kit, P/N 17112679 per the procedure in Section 6E of the Service Manual. The new TPS will have a yellow dot at the connector area for easier identification.

Part is currently available from GMSPO.

Note: The lack of 4th gear, no TCC and harsh transmission shift concerns are only associated on truck applications with the HYDRA-MATIC 4L80-E (4 speed automatic) electronic transmission.

Use applicable labor times.