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

WARNING: This page is about a different car, the 2006 Mercury Milan, 2006 Lincoln Zephyr, and 2006 Ford Fusion. 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.

D1 CHECK THE RCM C310b FOR DAMAGE
NOTE: The high speed CAN diagnostics requires depowering of the supplemental restraint system (SRS) when disconnecting the restraint control module (RCM) C310b. When key ON occurs to carry out the data link diagnostic test, diagnostic trouble codes (DTCs) may be stored in both the RCM and the occupant classification sensor. These DTCs should be cleared when network diagnostics are completed.
- Key in OFF position.
- Depower the supplemental restraint system (SRS). Refer to SUPPLEMENTAL RESTRAINT SYSTEM .
- Disconnect: RCM C310b.
- Inspect the RCM C310b for damage.
- Is the RCM C310b OK?
Yes : GO to D2.

No : REPAIR the RCM C310b as necessary. CONNECT the RCM C310b. REPOWER the SRS. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . CARRY OUT the data link diagnostics test.
D2 CHECK THE HIGH SPEED CAN CIRCUITS BETWEEN THE DLC AND THE RCM FOR AN OPEN
- Measure the resistance between the RCM C310b-18, circuit VDB04 (WH/BU), harness side and the DLC C251-6, circuit VDB04 (WH/BU), harness side.
  
  Fig 1: Checking High Speed CAN Circuits Between DLC And RCM For Open (1 Of 2)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the RCM C310b-17, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
  
  Fig 2: Checking High Speed CAN Circuits Between DLC And RCM For Open (2 Of 2)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
Yes : GO to D3.

No : REPAIR the circuit. CONNECT the RCM C310b. REPOWER the SRS. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . CARRY OUT the data link diagnostics test.
D3 CHECK FOR CORRECT RCM OPERATION
- Disconnect all the RCM connectors.
- Check for:
  - Corrosion
  - Pushed-out pins
- Connect all the RCM module connectors and make sure they seat correctly.
- Repower the SRS. Refer to SUPPLEMENTAL RESTRAINT SYSTEM .
- 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 DTCs. REPEAT the self-test. CARRY OUT the data link diagnostics test.

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. CARRY OUT the data link diagnostics test.