Brakes - ABS Code 9 Misdiagnosis
89chevy07Subject: REAR WHEEL ANTI-LOCK (RWAL) CODE 9 MISDIAGNOSIS
Model and Year: 1988-89 C, K TRUCKS 1989 S/T, M TRUCKS
Number: 89-113-5
Section: 5
Date: MARCH, 1989
TO: ALL CHEVROLET DEALERS
The instrument panel brake warning light (I.P.) will only come on when an abnormal condition exists within the RWAL system. The ECU module will only store one condition (or code) at a time. The vehicle should be test driven after the initial condition has been resolved to determine if any other conditions (codes) exist.
It should be noted that if the I.P. brake warning light is not on, it can be induced to come on by grounding diagnostic terminal "H" to "A" for more than 20 seconds. When this occurs, a Code 9 will be set.
This is a peculiarity with the RWAL system, and should not be interpreted as a faulty condition. Technicians who have accidentally induced a Code 9 in this manner should simply clear the code prior to returning the vehicle to the customer.