1990 Corvette: Service Bulletin: Inflatable Restraint Indicator Lamp Stays On

Subject: INFLATABLE RESTRAINT INDICATOR LAMP STAYS ON
Model and Year: 1990 Y CAR
Source: Chevrolet Service Bulletin
Bulletin Number: 90-98-0A - (01/03/1990)

CONDITION: The "INFL REST" indicator lamp may stay lit after the 5 second (ignition on) bulb check. This condition may occur right after the vehicle has been worked on for other reasons, such as cluster or steering column repairs.

CAUSE: If the ignition is turned on while any component of the SIR (Supplemental Inflatable Restraint) system is disconnected, or the cluster fuse feeding the indicator lamp circuit is blown, a malfunction code will be stored in the DERM (Diagnostic Energy Reserve Module).

Components that will set codes if disconnected with the ignition on are:

- Driver Information Center (DIC) (Code 42 - Indicator Lamp; Open Circuit)

- Steering column SIR connector (Code 35 - Inflator Squib; Open Circuit)

- Front crash sensors (LH & RH) (Codes 15 or 25 - Front Sensor; Open Circuit)

CORRECTION: Clear malfunction codes from the DERM using the following procedure:

1. Turn ignition "OFF". 2. Ground ALDL terminal ’K". 3. Turn ignition "ON". 4. Wait for fault codes to begin flashing (approx. 5 seconds). When the codes begin flashing, unground ALDL terminal "K" for 3 seconds +/- 1/2 second. 5. After ungrounding ALDL terminal "K" as described in step 4 above, ground it again for 3 seconds +/- 1/2 second.

6. Unground ALDL terminal "K, and wait 10 seconds. Before turning ignition off, verify that Code 12 is the only code being flashed. If not, codes have not been properly cleared. Begin clearing procedure again starting with Step 1.

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.