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

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

W1 RETRIEVE THE RECORDED DTCS FROM BOTH CONTINUOUS AND ON-DEMAND SELF-TESTS - RESTRAINT CONTROL MODULE (RCM)
- Check for recorded restraint control module (RCM) DTCs from the continuous and on-demand self-tests.
- Are any RCM DTCs recorded?
- Yes : If RCM DTC B1869 or B1870 are retrieved, GO to W3.
  For all other RCM DTCs, REFER to SUPPLEMENTAL RESTRAINT SYSTEM .
- No : GO to W2.
W2 CHECK THE RESTRAINT CONTROL MODULE (RCM) OPERATION
NOTE: The resistance during this test should be greater than 10,000 ohms for approximately 4 seconds then switch to less than 5 ohms during bulb prove out.
- Disconnect: Instrument Cluster C220a.
- Key in ON position.
- Measure the resistance between the instrument cluster C220a-22, circuit 31S-JA14 (BK/GN), harness side and ground.
  
  Fig 1: Measuring Resistance Between Instrument Cluster C220A-22, Circuit 31S-Ja14 (BK/GN) And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms during prove out then change to greater than 10,000 ohms?
- Yes : GO to W6.
- No : GO to W3.
W3 CHECK CIRCUIT 31S-JA14 (BK/GN) FOR AN OPEN OR A SHORT TO GROUND
- Key in OFF position.
- Deactivate the air bag system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM .
- Disconnect: Restraint Control Module (RCM) C310a.
- Measure the resistance between the instrument cluster C220a-22, circuit 31S-JA14 (BK/GN), harness side and the RCM C310a-19, circuit 31S-JA14 (BK/GN), harness side; and between the instrument cluster C220a-22, circuit 31S-JA14 (BK/GN), harness side and ground.
  
  Fig 2: Checking Circuit 31S-Ja14 (BK/GN) For Open Or Short To Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms between the instrument cluster and the RCM, and greater than 10,000 ohms between the instrument cluster and ground?
- Yes : GO to W4.
- No : REPAIR the circuit. CONNECT the RCM. ACTIVATE the air bag system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . CLEAR the DTCs. REPEAT the self-test.
W4 CHECK CIRCUIT 31S-JA14 (BK/GN) FOR A SHORT TO VOLTAGE
- Key in ON position.
- Measure the voltage between the instrument cluster C220a-22, circuit 31S-JA14 (BK/GN), harness side and ground.
  
  Fig 3: Measuring Voltage Between Instrument Cluster C220A-22, Circuit 31S-Ja14 (BK/GN) And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage indicated?
- Yes : REPAIR the circuit. CONNECT the RCM. ACTIVATE the air bag system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . CLEAR the DTCs. REPEAT the self-test.
- No : GO to W5.
W5 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 . 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. CLEAR the DTCs. TEST the system for normal operation.
W6 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 in this article. 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. CLEAR the DTCs. REPEAT the self-test.