Engine Controls - SES Light Code 32, EGR System
89chevy31Subject: SERVICE ENGINE SOON LIGHT - CODE 32 STORED
Model and Year: 1988-89 M VAN WITH 4.3L (VIN Z) ENGINE
Number: 89-187-6E
Section: 6E
Date: JUNE 1989
TO: ALL CHEVROLET DEALERS
Some 1988 and 1989 model year M-vans equipped with the 4.3L engine (VIN Code Z) may experience a Code 32 - EGR System malfunction. The customer may not experience a change in performance or driveability with a Code 32 set.
If normal diagnostics do not reveal the cause for Code 32, the following steps should be taken to correct the condition:
1. Check the TCC ([1][2]Torque Converter Clutch) engagement solenoid for a short-circuit, and correct if the condition is found. Refer to the "Fuel and Emission Service Manual Supplement" in the Transmission Controls section for details on TCC diagnostics.
2. If the TCC circuit is operating properly, replace the exhaust oxygen sensor (P/N 25105901). The sensor is currently available from GMSPO.
3. Confirm closed-loop operation of the engine. It is recommended that the following conditions be satisfied during confirmation to determine if the repairs made were effective. These conditions establish the requirements for running a Code 32 test:
* Road Load at normal operating temperature
* Constant Throttle Position -
TPS voltage = 1.3 V (minimum = 1.1 V, maximum = 1.5 V)
* Vehicle Speed = 45 mph
(minimum = 35 mph, maximum = 55 mph)
* Length of test drive - at least 2 to 3 miles
Use applicable labor operation and time per the Labor time Guide.