Pinpoint Test C: The Restraints Control Module (RCM) Does Not Respond To The Scan Tool

WARNING: This page is about a different car, the 2007 Lincoln MKX and 2007 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Never probe the connectors on the air bag module. Doing so can result in air bag deployment, which can result in personal injury.

WARNING: The safety belt pretensioner is a pyrotechnic device. Always wear safety glasses when repairing an air bag equipped vehicle and when handling a safety belt buckle pretensioner or safety belt retractor pretensioner. Never probe a pretensioner electrical connector. Doing so could result in pretensioner or air bag deployment and could result in personal injury.

NOTE: The supplemental restraint system (SRS) must be fully operational and free of faults before releasing the vehicle to the customer.

NOTE: Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the pinpoint test.

C1 CHECK THE RCM CONNECTION
- Key in OFF position.
- Depower the SRS. Refer to SUPPLEMENTAL RESTRAINT SYSTEM .
- Disconnect: RCM C310a
- Disconnect: RCM C310b
- Are RCM C310a pin 12 and RCM C310b pins 17 and 18 OK?
1. YES : Go to C2.
2. NO : REPAIR the RCM connector pins as necessary. REPOWER the SRS. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . CLEAR the DTCs. REPEAT the network test with the scan tool.
C2 CHECK THE RCM VOLTAGE SUPPLY CIRCUIT CBP46 (WH/BU) FOR AN OPEN
- Deactivate the SRS. Refer to SUPPLEMENTAL RESTRAINT SYSTEM .
- Repower the SRS. Refer to SUPPLEMENTAL RESTRAINT SYSTEM .
- Key in ON position.
- Measure the voltage between the RCM C310a-12, circuit CBP46 (WH/BU), harness side and ground.
- Is the voltage greater than 10 volts?
1. YES : Go to C3.
2. NO : VERIFY the smart junction box (SJB) fuse 46 (7.5A) is OK. If OK, REPAIR the circuit. REACTIVATE the SRS. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . CLEAR the DTCs. REPEAT the network test with the scan tool.
C3 CHECK THE RCM CASE GROUND
- Key in OFF position.
- Measure the resistance between the RCM case and a good chassis ground.
- Is the resistance less than 5 ohms?
1. YES : Go to C4.
2. NO : REPAIR the RCM case ground as necessary. REACTIVATE the SRS. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . CLEAR the DTCs. REPEAT the network test with the scan tool.
C4 CHECK THE HS-CAN CIRCUITS BETWEEN THE DATA LINK CONNECTOR (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.
- Measure the resistance between the RCM C310b-17, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
- Are the resistances less than 5 ohms?
1. YES : Go to C5.
2. NO : REPAIR the circuit in question. REACTIVATE the SRS. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . CLEAR the DTCs. REPEAT the network test with the scan tool.
C5 CHECK FOR CORRECT RCM OPERATION
- Disconnect all the RCM connectors.
- Check for:
  - corrosion
  - damaged pins
  - 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?
1. YES : INSTALL a new RCM. REACTIVATE the SRS. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . CLEAR the DTCs. REPEAT the network test with the scan tool.
2. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. REACTIVATE the SRS. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . CLEAR the DTCs. REPEAT the network test with the scan tool.