Pinpoint Test F: The OCSM 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.

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

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 .

F1 CHECK THE OCSM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Ignition OFF.
- Depower the SRS . Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING
- Disconnect: OCSM C3159.
- Deactivate the SRS . Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION .
- Repower the SRS . Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING
- Ignition ON.
- Measure the voltage between the OCSM C3159-1, circuit CBP46 (WH/BU), harness side and ground.
  
  Fig 1: Measuring Voltage Between OCSM C3159-1, Circuit CBP46 (WH/BU) And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to F2.
- 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 (SRS) DEACTIVATION AND REACTIVATION . CLEAR the DTCs. REPEAT the network test with the scan tool.
F2 CHECK THE OCSM GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the OCSM C3159-14, circuit GD127 (BK/BU), harness side and ground.
  
  Fig 2: Measuring Resistance Between OCSM C3159-14, Circuit GD127 (BK/BU) And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to F3.
- No : REPAIR the circuit. REACTIVATE the SRS . CONNECT the negative battery cable. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION . CLEAR the DTCs. REPEAT the network test with the scan tool.
F3 CHECK THE HS-CAN CIRCUITS BETWEEN THE OCSM AND THE DLC FOR AN OPEN
- Measure the resistance between the OCSM C3159-18, circuit VDB04 (WH/BU), harness side and the Data Link Connector (DLC) C251-6, circuit VDB04 (WH/BU), harness side.
  
  Fig 3: Measuring Resistance Between OCSM C3159-18 Circuit VDB04 (WH/BU) And Data Link Connector C251-6, Circuit VDB04 (WH/BU)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the OCSM C3159-9, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
  
  Fig 4: Measuring Resistance Between OCSM C3159-9, 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 F4.
- No : REPAIR the circuit. REACTIVATE the SRS . CONNECT the negative battery cable. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION . CLEAR the DTCs. REPEAT the network test with the scan tool.
F4 CHECK FOR CORRECT OCSM OPERATION

Disconnect the OCSM connector.
Check for:
- corrosion
- damaged pins
- pushed-out pins
Connect the OCSM connector and make sure it seats correctly.
Verify the concern is still present.
Is the concern still present?

Yes : INSTALL a new OCSM. REFER to REMOVAL AND INSTALLATION REACTIVATE the SRS . 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. REACTIVATE the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION . CLEAR the DTCs. REPEAT the network test with the scan tool.