Pinpoint Test B: The Restraint Control Module (RCM) Does Not Respond To The Diagnostic Tool

WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector.

B1 CHECK THE ISO 9141 COMMUNICATION NETWORK CIRCUIT BETWEEN THE RCM AND THE DLC FOR AN OPEN
- Key in OFF position.
- Depower the supplemental restraint system (SRS). Refer to SUPPLEMENTAL RESTRAINT SYSTEM .
- Disconnect: RCM C2041a.
- Measure the resistance between the RCM C2041a-11, circuit 70 (LB/WH), harness side and the DLC C251-7, circuit 70 (LB/WH), harness side.
  
  Fig 1: Checking ISO 9141 Communication Network Circuit Between RCM And DLC For An Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes : GO to B2.

No : REPAIR the circuit. CONNECT the RCM C2041a. REPOWER the SRS. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . CARRY OUT the diagnostic tool data link test.
B2 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 . CLEAR the diagnostic trouble codes (DTCs). REPEAT the self-test. CARRY OUT the diagnostic tool data link test.

No : REPOWER the SRS. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . 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. CARRY OUT the diagnostic tool data link test.