(SIR) - System Wiring Repair Procedures: Overview
9218chevy03
Number: 90-73-10
Section: 10
Date: October 1989
Corporate Bulletin No.: 919005
Subject:
SUPPLEMENTAL INFLATABLE, RESTRAINT (SIR) SYSTEM WIRING REPAIR PROCEDURES
Model and Year:
1990 Y CAR WITH 5.7L (VIN CODE J, 8) ENGINES
TO: ALL CHEVROLET DEALERS
The 1990 model year is the first year select Chevrolet vehicles will be equipped with Supplemental Inflatable Restraint (SIR) Systems. Throughout General Motors four different systems are utilized in total. Each system may appear the same, however, unique design differences require different service procedures for each. Considering these facts, it is extremely important that the correct service manual and service bulletin be used during diagnosis and repair if required.
The following Supplemental Inflatable Restraint (SIR) system wiring repair information applies to CORVETTE ONLY.
Special wiring repair procedures have been developed for use on the Supplemental Inflatable Restraint (SIR) System due to the sensitive nature of the circuitry. These specific procedures and instructions must be followed when working with SIR System wiring and wiring components (such as connectors and terminals). Some system components require replacement, while others may be repaired. Always follow the guidelines given below when working with SIR wiring.
WIRING REPAIR
When repairs to the SIR system wiring are made, always use the Crimp & Seal splices, crimping tools, and repair instructions supplied with Wiring Repair Kit J 38125-A. NO ALTERNATE REPAIR METHODS ARE ALLOWED. If the proper tools and/or components are not available, contact Chevrolet Technical Assistance to arrange for proper service of the SIR system.
When there is a reference made to the "DERM side of the harness" it means that part of a circuit's wiring which runs FROM the DERM TO the connector. When a reference is made to the "vehicle side of the harness" it means; that portion of a circuit's wiring which runs FROM a system in the vehicle TO the connection point with the DERM.
The following items may NOT be serviced; if they are damaged, the entire component, with its associated wiring, must be replaced.
1. DERM-to-SIR Coil wiring harness.
2. DERM-to-I/P Harness wiring harness.
3. DERM-to-Sensor Harness, both left and right sides.
4. DERM-to-Sensor Harness connectors.
5. Forward Discriminating Sensor wiring pigtail and connector, both left and right sides.
6. SIR Coil-to-DERM Connector.
7. SIR Coil-to-Inflator Module Connector.
8. SIR Coil wiring.
The following items may be REPLACED:
1. The DERM-to-SIR Coil Connector half at the base of the steering column. This connector half (with wiring leads) is supplied in Kit J 38125-A, and should be replaced as an assembly. The SIR Coil-to-DERM Connector half, which mates with this connector, cannot be serviced; if it is damaged, the SIR Coil Assembly must be replaced.
2. Damaged terminals in either the DERM side or the vehicle side of the DERM-to-I/P Harness connector. If there is a problem with a terminal in these connectors (natural color; 10-way), back the damaged terminal out of the connector half, cut the wire, and splice in a new terminal-with-lead assembly. Terminal-and-lead assemblies are provided with Kit J 38125-A. Do not replace individual terminals by selecting one from the many terminals provided with J 38125-A; always use the prefabricated terminal-with-lead assemblies.
The following items may be REPAIRED:
1. The VEHICLE side of the I/P Harness wiring that connects to the DERM, but not the DERM-to-I/P Harness wiring. If the vehicle side of the I/P Harness is damaged, the wire should be repaired by splicing in a new section of wire of the same gauge size (.5, .8, 1.0, etc.). If the DERM-to-I/P Hamess wiring is damaged, the DERM must be replaced. No DERM harness wiring can be repaired.