SES LIGHT - FALSE CODE 45 (DIAGNOSE/REPLACE PROM)

SUBJECT: "SERVICE ENGINE SOON" LIGHT FALSE CODE 45 (DIAGNOSE/REPLACE PROM)

VEHICLES AFFECTED: 1992 "B" MODEL WITH 4.3L ENGINE (VIN Z - PRO LB4)

CONDITION:

Some owners of 1992 model year B with 4.3L (RPO LB4) engines may comment on a service engine soon light - Code 45 - oxygen sensor (02) rich. The vehicle does not exhibit any driveability symptoms.

CAUSE:

The original calibration sets a false code 45.

CORRECTION:

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

2. If no problems are found using these diagnostic procedures replace the PROM (Programmable read only memory) with the following GMSPO part.

P/N Broadcast Code Scanner I.D. 16191686 BFKF 1711

For vehicles repaired under warranty use:

Labour Time: 0.5 Hr

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