Inflatable Restraint Steering Wheel Module Coil Centering

Fig 1: View Of Block Tooth Of Steering Shaft Assembly In 12 O'clock Position

Courtesy of GENERAL MOTORS CORP.

NOTE: The new SIR coil assembly will be centered. Improper alignment of the SIR coil assembly may damage the unit, causing an inflatable restraint malfunction.

IMPORTANT: If double wire harness strap is installed onto the wire harness assembly and column, you must reuse the holder for the wire straps during installation.
Remove the wire harness strap(s) where necessary.

Verify the following conditions before centering the SIR coil:
- The wheels on the vehicle are straight ahead.
- The block tooth (1) of the steering shaft assembly is in the 12 o'clock position.
- The ignition switch is in the LOCK position.

Fig 2: Centering SIR Coil (With Centering Window & Spring Service Lock)

Courtesy of GENERAL MOTORS CORP.

If the front (5) of the SIR coil has a centering window (4), and the back side (2) includes a spring service lock (1), perform the following steps:
1. Hold the SIR coil with the face up.
2. While depressing the spring service lock, rotate the coil hub clockwise until the coil ribbon stops.
3. Rotate the coil hub slowly, counterclockwise, until the centering window appears yellow and both arrows (3) line up.
4. Release spring service lock between the locking tab. The SIR coil is now centered.
5. Align the centered SIR coil with the horn tower and slide onto the steering shaft assembly.

Fig 3: Centering SIR Coil (With Centering Window, Without Spring Service Lock)

Courtesy of GENERAL MOTORS CORP.

If the front (4) of the SIR coil has a centering window (3), and the back side (1) includes NO spring service lock, perform the following steps:
1. Hold the SIR coil with the face up.
2. Rotate the coil hub clockwise until the coil ribbon stops.
3. Rotate the coil hub slowly, counterclockwise until the centering window appears yellow and both arrows (2) line up. This is the CENTER position.
4. While holding the coil hub in the CENTER position, align the SIR coil with the horn tower and slide onto the steering shaft assembly.

Fig 4: Centering SIR Coil (No Centering Window, But Back Side Includes A Spring Service Lock)

Courtesy of GENERAL MOTORS CORP.

If the front side (3) of the SIR coil has NO centering window, but the back side (2) includes a spring service lock (1), perform the following steps:
1. Hold the SIR coil with the back side up.
2. While depressing the spring service lock, rotate the coil hub in the direction of the arrow (4) until the coil ribbon stops.
3. Still pressing the spring service lock, rotate the coil hub in the opposite direction 21/2 revolutions.
4. Release the spring service lock between locking tabs. The SIR coil is now centered.
5. Align the centered SIR coil with the horn tower and slide onto the steering shaft assembly.

Fig 5: Centering SIR Coil (Without Centering Window, Without Spring Service Lock)

Courtesy of GENERAL MOTORS CORP.

If the front side (2) of the SIR coil has NO centering window, and the back side (1) includes NO spring service lock, perform the following steps:
1. Hold the SIR coil with the face up.
2. Rotate the coil hub in the direction of the arrow until the coil ribbon stops.
3. Rotate the coil hub, slowly, counterclockwise, for 21/2 revolutions. This is the CENTER position.
4. While maintaining the coil hub in the CENTER position, align the centered SIR coil with the horn tower and slide onto the steering shaft assembly.
If double wire harness strap is installed onto the wire harness assembly and column, you must route the wires up against the steering column. One wire harness strap will surround one lead from the coil to the steering column. The other wire harness strap will surround all leads to the steering column.