Pinpoint Test D : The OCSM (Occupant Classification System Module) Does Not Respond To The Diagnostic Scan Tool

WARNING: This page is about a different car, the 2018 Ford Fiesta. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings.

NOTE: The Supplemental Restraint System (SRS) must be fully operational and free of faults before releasing the vehicle to the customer.

D1 CHECK THE OCSM (OCCUPANT CLASSIFICATION SYSTEM MODULE) VOLTAGE SUPPLY CIRCUITS FOR AN OPEN

Ignition ON.

Disconnect OCSM C3159.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3159-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes

GO to D2

No	VERIFY the CJB fuse 4 (7.5A) is OK. If OK, REPAIR the circuit in question. If not OK, REFER to OEM Electrical Wiring Diagram Introduction to identify the possible causes of the circuit short.

D2 CHECK THE OCSM (OCCUPANT CLASSIFICATION SYSTEM MODULE) GROUND CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect negative battery cable.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3159-4	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance less than 3 ohms?

Yes

GO to D3

No	REPAIR the circuit. CONNECT negative battery cable.

D3 CHECK THE HS-CAN (HIGH-SPEED CONTROLLER AREA NETWORK) CIRCUITS BETWEEN THE OCSM (OCCUPANT CLASSIFICATION SYSTEM MODULE) AND THE DLC (DATA LINK CONNECTOR) FOR AN OPEN

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3159-2	Courtesy of FORD MOTOR COMPANY	C251-6
C3159-3	Courtesy of FORD MOTOR COMPANY	C251-14

Are the resistances less than 3 ohms?

Yes	CONNECT negative battery cable. GO to D4

No	REPAIR the circuit in question. CONNECT negative battery cable.

D4 CHECK FOR CORRECT OCSM (OCCUPANT CLASSIFICATION SYSTEM MODULE) OPERATION

Ignition OFF.

Disconnect and inspect the OCSM connector.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

Reconnect the OCSM connector. Make sure it seats and latches correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new OCSM. REFER to: Occupant Classification System (OCS) Sensor .

No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.