Pinpoint Test D: The RCM Does Not Respond To The Scan Tool

WARNING: This page is about a different car, the 2013 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Never disassemble or tamper with seat belt deployable components, including pretensioners, load limiters and inflators. Never back probe deployable device electrical connectors. Tampering or back probing may cause an accidental deployment and result in personal injury or death.

WARNING: Never probe the electrical connectors on airbag, Safety Canopy or side air curtain assemblies. Failure to follow this instruction may result in the accidental deployment of these assemblies, which increases the risk of serious personal injury or death.

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.

NOTE: Failure to disconnect the battery when instructed results in false resistance readings. Refer to BATTERY, MOUNTING AND CABLES .

D1 CHECK THE RCM CONNECTION
- Ignition OFF.
- Depower the SRS. Refer to SUPPLEMENTAL RESTRAINT SYSTEM .
- Disconnect: RCM C2041A.
- Disconnect: RCM C2041B.
- Inspect the RCM connector for damaged, pushed out or corroded pins.
- Are RCM C2041A pin 13 and RCM C2041B pins 9 and 10 OK?
- Yes : GO to D2.
- 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.
D2 CHECK THE RCM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Repower the SRS. Refer to SUPPLEMENTAL RESTRAINT SYSTEM .
- Ignition ON.
- Measure the voltage between the RCM C2041A-13, circuit CBP31 (BU/OG), harness side and ground.
  
  Fig 1: Measuring Voltage Between RCM C2041A-13, Circuit CBP31 (BU/OG) And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to D3.
- No : VERIFY the Smart Junction Box (SJB) fuse 31 (10A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the SYSTEM WIRING DIAGRAMS to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the network test with the scan tool.
D3 CHECK THE RCM CASE GROUND
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the RCM case and a good chassis ground.
- Is the resistance less than 5 ohms?
- Yes : GO to D4.
- No : REPAIR the RCM case ground as necessary. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
D4 CHECK THE HS-CAN CIRCUITS BETWEEN THE RCM AND THE DLC FOR AN OPEN
- Measure the resistance between the RCM C2041B-10, circuit VDB04 (WH/BU), harness side and the Data Link Connector (DLC) C251-6, circuit VDB04 (WH/BU), harness side.
  
  Fig 2: Measuring Resistance Between RCM C2041B-10, Circuit VDB04 (WH/BU) And Data Link Connector (DLC) C251-6, Circuit VDB04 (WH/BU)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the RCM C2041B-9, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
  
  Fig 3: Measuring Resistance Between RCM C2041B-9, Circuit VDB05 (WH) And DLC C251-14, Circuit VDB05 (WH)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes : CONNECT the negative battery cable. GO to D5.
- No : REPAIR the circuit in question. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
D5 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?
- Yes : INSTALL a new RCM. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . CLEAR the DTCs. REPEAT the network test with the scan tool.
- 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 network test with the scan tool.