Inflatable Restraint Steering Wheel Module Coil Centering

1999 GMC Forward Control 5.7 R, AutomaticSECTION Inflatable Restraint Steering Wheel Module Coil Centering
WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
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.
  1. Verify the following conditions before centering the SIR coil:
    • The wheels on the vehicle are pointed straight ahead.
    • The block tooth (1) of the steering shaft is in the 12 o'clock position.
    • The ignition switch is in the LOCK position, or J 42640 is installed in the upper tilt head.
    Fig 1: View Of Block Tooth Of Steering Shaft Assembly In 12 O'clock Position
    GM293254Courtesy of GENERAL MOTORS CORP.
  2. Fig 2: Centering SIR Coil (With Centering Window & Spring Service Lock)
    GM603737Courtesy of GENERAL MOTORS CORP.
  3. If the front (5) of the SIR coil has a centering window (4), and the back side (2) has a spring service lock (1), perform the following steps:
    1. Hold the 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, counter clockwise, until the centering window appears yellow and both arrows (3) line up.
    4. Release the 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 the coil onto the steering shaft.
  4. Fig 3: Centering SIR Coil (With Centering Window, Without Spring Service Lock)
    GM594558Courtesy of GENERAL MOTORS CORP.
  5. If the front (4) of the SIR coil has a centering window (3) and the back side (1) does NOT have a spring service lock, perform the following steps:
    1. Hold the coil with the face up.
    2. Rotate the coil hub clockwise until the coil ribbon stops.
    3. Rotate the coil hub slowly, counter clockwise until the centering window appears yellow and both arrows (2) line up. This is center position.
    4. While holding the coil hub in center position, align the SIR coil assembly with the horn tower and slide onto the steering shaft.
  6. Fig 4: Centering SIR Coil (No Centering Window, But Back Side Includes A Spring Service Lock)
    GM603738Courtesy of GENERAL MOTORS CORP.
  7. If the front side (3) of the SIR coil does NOT have a centering window, but the back side (2) has 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 counter clockwise until the coil ribbon stops.
    3. Still pressing the spring service lock, rotate the coil hub in the opposite direction 2.5 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.
  8. Fig 5: Centering SIR Coil (Without Centering Window, Without Spring Service Lock)
    GM603739Courtesy of GENERAL MOTORS CORP.
  9. If the front side (3) of the SIR coil does NOT have a centering window, and the back side (2) does NOT have a spring service lock (1), perform the following steps:
    1. Hold the coil with the face up.
    2. Rotate the coil hub clockwise until the coil ribbon stops.
    3. Rotate the coil hub, slowly, counter clockwise, for 2.5 revolutions. This is center position.
    4. While maintaining the coil hub in center position, align the centered SIR coil with the horn tower and slide onto the steering shaft.
RENDER: 1.0x

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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
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