Pinpoint Test N: The Air Bag Warning Indicator Is Never On

WARNING: This page is about a different car, the 2005 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.

N1 CHECK THE AIR BAG WARNING INDICATOR OPERATION
- Key in OFF position.
- Deactivate the air bag system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM .
- Disconnect: RCM C310a.
- Key in ON position.
- Does the air bag indicator lamp illuminate?
- Yes : GO to N3.
- No : GO to N2.
N2 CHECK CIRCUIT 1632 (TN/LB) FOR A SHORT TO GROUND
- Key in OFF position.
- Disconnect: Instrument Cluster C220a.
- Measure the resistance between the instrument cluster C220a-4, circuit 1632 (TN/LB), harness side and ground.
  
  Fig 1: Measuring Resistance Between Instrument Cluster C220a-4, Circuit 1632 (TN/LB), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?
- Yes : REPAIR the circuit. ACTIVATE the air bag system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . TEST the system for normal operation.
- No : GO to N4.
N3 CHECK FOR CORRECT RCM OPERATION
- Disconnect all the RCM connectors.
- Check for:
  - Corrosion
  - Pushed-out pins
- Connect all the RCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes : INSTALL a new RCM. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . ACTIVATE the air bag system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . TEST the system for normal operation.
- No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ACTIVATE the air bag system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM .
N4 CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION
- Disconnect all the instrument cluster connectors.
- Check for:
  - Corrosion
  - Pushed-out pins
- Connect all the instrument cluster connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes : INSTALL a new instrument cluster. REFER to INSTRUMENT CLUSTER . ACTIVATE the air bag system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM SRS DEACTIVATION AND REACTIVATION . TEST the system for normal operation.
- No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ACTIVATE the air bag system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM SRS DEACTIVATION AND REACTIVATION .