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

WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Never probe the electrical connectors on safety belt buckle/retractor pretensioners or adaptive load limiting retractors. Failure to follow this instruction may result in the accidental deployment of the safety belt pretensioners or adaptive load limiting retractors, which increases the risk of serious personal injury or death.

WARNING: Never probe the electrical connectors on air bag, Safety Canopy® or side air curtain modules. Failure to follow this instruction may result in the accidental deployment of these modules, 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 will result in false resistance readings. Refer to BATTERY, MOUNTING AND CABLES .

E1 CHECK THE RCM CONNECTION
- Ignition OFF.
- Depower the SRS . Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Disconnect: RCM C310a.
- Disconnect: RCM C310b.
- Inspect the RCM connector for damaged, pushed out or corroded pins.
- Are RCM C310a pin 13 and RCM C310b pins 9 and 10 OK?
- Yes : GO to E2.
- No : REPAIR the RCM connector pins as necessary. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING CLEAR the DTCs. REPEAT the network test with the scan tool.
E2 CHECK THE RCM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Repower the SRS . Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING
- Ignition ON.
- Measure the voltage between the RCM C310a-13, circuit CBP32 (GN/VT), harness side and ground.
  
  Fig 1: Measuring Voltage Between RCM C310a-13, Circuit CBP32 (GN/VT), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to E3.
- No : VERIFY the Smart Junction Box (SJB) fuse 32 (10A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the appropriate SYSTEM WIRING DIAGRAMS article to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the network test with the scan tool.
E3 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 E4.
- No : REPAIR the RCM case ground as necessary. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
E4 CHECK THE HS-CAN CIRCUITS BETWEEN THE RCM AND THE DLC FOR AN OPEN
- Measure the resistance between the RCM C310b-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 C310b-10, Circuit VDB04 (WH/BU), Harness Side And DLC C251-6, Circuit VDB04 (WH/BU)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the RCM C310b-9, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
  
  Fig 3: Measuring Resistance Between RCM C310b-9, Circuit VDB05 (WH), Harness Side 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 E5.
- No : REPAIR the circuit in question. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
E5 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 REMOVAL AND INSTALLATION 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.