Visual Inspection and Diagnostic Pre-checks

Inspect for a damaged passenger seatbelt buckle or Belt Tension Sensor (BTS).
Inspect for a damaged passenger seat cushion wiring harness.
Inspect for a loose or damaged OCSM or Belt Tension Sensor (BTS) connector.
Inspect for a damaged OCSM.

WARNING: Incorrect repair techniques or actions can cause an accidental SRS deployment. Never compromise or depart from these instructions. Failure to precisely follow all instructions could result in serious personal injury from an accidental deployment.

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

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: Only disconnect or reconnect SRS components when instructed to do so within a pinpoint test step. Failure to follow this instruction may result in incorrect diagnosis of the SRS.

NOTE: Always make sure the correct SRS component is being installed. Parts released for other vehicles may not be compatible even if they appear physically similar. Check the part number listed in the Ford parts catalog to make sure the correct component is being installed. If an incorrect SRS component is installed, DTCs may set.

NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.

Fig 1: Occupant Classification System Module Connector (C3043)

Courtesy of FORD MOTOR CO.

CIRCUIT AND PIN DESCRIPTION

Circuit	Pin
BTS VREF (Belt Tension Switch Voltage Reference) - LR142	5 (YELLOW/BLUE)
BTS SIG (Belt Tension Switch Signal) - VR210	6 (BLUE/BROWN)

Fig 2: Restraint Control Module-A Connector (C310A)

Courtesy of FORD MOTOR CO.

CIRCUIT AND PIN DESCRIPTION

Circuit

AXB1: CHECK FOR DTC U3003:16 AND U3003:17

WARNING: Before beginning any service procedure in this article, refer to Safety Warnings in General Information article. Failure to follow this instruction may result in serious personal injury.

NOTE: Diagnose all network-related (lost communication) DTCs first.

Ignition ON, engine OFF.
Carry out the RCM self-test.
Is DTC U3003:16 or U3003:17 retrieved DTC during the self-test?

Yes	No
REFER to the DTC INDEX .	Go to AXB2.

AXB2: RETRIEVE OCSM DIAGNOSTIC TROUBLE CODES (DTCS)

Review the OCSM Diagnostic Trouble Codes (DTCs) retrieved from the OCSM self-test.
Is DTC B0061:11, B0061:12, B0061:13, B0061:1C or B0061:64 retrieved on-demand during self-test?

Yes	No
This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-demand during the self-test. For DTC B0061:11, Go to AXB3. For DTC B0061:12, Go to AXB6. For DTC B0061:13, Go to AXB8. For DTC B0061:1C, Go to AXB10. For DTC B0061:49, INSTALL a new OCS sensor. REFER to the appropriate procedure in Supplemental Restraint System article. Go to AXB14.	This is an intermittent fault when present as a CMDTC only. Go to AXB13.

AXB3: CHECK THE BELT TENSION SENSOR (BTS)

NOTE: This pinpoint test step attempts to change the fault reported by the OCSM by inducing a different fault condition. If the fault reported changes, this indicates the OCSM is functioning correctly and is not the source of the fault.

Ignition OFF.
Passenger Seatbelt Tension Sensor (BTS) connector disconnected.
Carry out the OCS self-test.
NOTE: DIAGNOSTIC TIP: When viewing Diagnostic Trouble Codes (DTCs) with the Belt Tension Sensor (BTS) disconnected, an open circuit fault is normally retrieved.
Is DTC B0061:11 retrieved on-demand during self-test?

Yes	No
Go to AXB4.	INSTALL a new front passenger safety belt retractor pretensioner. REFER to the appropriate Removal and Installation procedure in Seatbelt Systems article Go to AXB14.

AXB4: CHECK THE BELT TENSION SENSOR (BTS) CIRCUITS FOR A SHORT TO GROUND OR SHORT TOGETHER

Ignition OFF.
OCSM connector disconnected. (C3043)

Measure the resistance between:

(+) Passenger Seatbelt Tension Sensor (BTS) Connector, Harness Side	(-)
BTS SIG	Ground

Measure the resistance between:

(+) Passenger Seatbelt Tension Sensor (BTS) Connector, Harness Side	(-) Passenger Seatbelt Tension Sensor (BTS) Connector, Harness Side
BTS SIG	GND

Is the resistance greater than 10, 000 ohms?

Yes	No
Go to AXB5.	REPAIR the circuit. Go to AXB14.

AXB5: CHECK THE BELT TENSION SENSOR (BTS) VREF CIRCUIT FOR AN OPEN

Measure the resistance between:

(+) OCSM (C3043) Connector, Harness Side	(-) Passenger Seatbelt Tension Sensor (BTS) Connector, Harness Side
BTS VREF - LR142 (YELLOW/BLUE) - Pin 5	BTS VREF

Is the resistance less than 0.5 ohm?

Yes	No
Go to AXB12.	REPAIR the circuit. Go to AXB14.

AXB6: CHECK THE BELT TENSION SENSOR (BTS) SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE

Ignition OFF.
Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering in Supplemental Restraint System article.
Passenger Side Airbag Assembly connector disconnected.
Passenger Seatbelt Tension Sensor (BTS) connector disconnected.
OCSM connector disconnected. (C3043)
Repower the SRS. Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Repowering in Supplemental Restraint System article.
Ignition ON, engine OFF.

Measure the voltage between:

(+) OCSM (C3043) Connector, Harness Side	(-)
BTS SIG - VR210 (BLUE/BROWN) - Pin 6	Ground

Is any voltage present?

Yes	No
REPAIR the circuit. Go to AXB14.	Go to AXB7.

AXB7: CHECK THE BELT TENSION SENSOR (BTS) GROUND CIRCUIT FOR AN OPEN

Ignition OFF.
Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering in Supplemental Restraint System article.

Measure the resistance between:

(+) Passenger Seatbelt Tension Sensor (BTS) Connector, Harness Side	(-)
GND	Ground

Is the resistance less than 3 ohms?

Yes	No
Go to AXB12.	REPAIR the circuit. Go to AXB14.

AXB8: CHECK THE BELT TENSION SENSOR (BTS)

Ignition OFF.
Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering in Supplemental Restraint System article.
Passenger Side Airbag Assembly connector disconnected.
Passenger Seatbelt Tension Sensor (BTS) connector disconnected.

Connect a 5 amp fused jumper wire between the following:

Point A Passenger Seatbelt Tension Sensor (BTS) Connector, Harness Side	Point B Passenger Seatbelt Tension Sensor (BTS) Connector, Harness Side
BTS SIG	GND

Repower the SRS. Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Repowering in Supplemental Restraint System article.
Ignition ON, engine OFF.
Carry out the OCS self-test.
NOTE: DIAGNOSTIC TIP: When viewing DTCs with the Belt Tension Sensor (BTS) circuits shorted together, a short to ground fault is normally retrieved.
Does the on-demand DTC change from B0061:13 to B0061:11?

Yes	No
REMOVE the fused jumper wire. INSTALL a new front passenger seatbelt retractor pretensioner assembly. REFER to the appropriate procedure in Seatbelt Systems article Go to AXB14.	Go to AXB9.

AXB9: CHECK THE BELT TENSION SENSOR (BTS) SIGNAL CIRCUIT FOR AN OPEN

Ignition OFF.
OCSM connector disconnected. (C3043)

Measure the resistance between:

(+) Passenger Seatbelt Tension Sensor (BTS) Connector, Harness Side	(-) OCSM (C3043) Connector, Harness Side
BTS SIG	BTS SIG - VR210 - Pin 6

Is the resistance less than 0.5 ohm?

Yes	No
Go to AXB12.	REPAIR the circuit. Go to AXB14.

AXB10: CHECK THE BELT TENSION SENSOR (BTS) SIGNAL CIRCUIT FOR A SHORT TO THE BELT TENSION SENSOR (BTS) VREF CIRCUIT

WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.

Ignition OFF.
OCSM connector disconnected. (C3043)
Passenger Seatbelt Tension Sensor (BTS) connector disconnected.

Measure the resistance between:

(+) Passenger Seatbelt Tension Sensor (BTS) Connector, Harness Side	(-) Passenger Seatbelt Tension Sensor (BTS) Connector, Harness Side
BTS SIG	BTS VREF

Is the resistance greater than 10, 000 ohms?

Yes	No
Go to AXB11.	REPAIR the circuits. Go to AXB14.

AXB11: CHECK BELT TENSION SENSOR (BTS) VOLTAGE OUTPUT

Ignition OFF.
Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering in Supplemental Restraint System article.
OCSM connector connected. (C3043)
Passenger Side Airbag Assembly connector disconnected.

Connect a 5 amp fused jumper wire between the following:

Point A Passenger Seatbelt Tension Sensor (BTS) Connector, Harness Side	Point B Passenger Seatbelt Tension Sensor (BTS) Connector, Component Side
GND	GND
BTS VREF	BTS VREF

Repower the SRS. Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Repowering in Supplemental Restraint System article.
Ignition ON, engine OFF.

Measure the voltage between:

(+) Passenger Seatbelt Tension Sensor (BTS) Connector, Component Side	(-)
BTS SIG	Ground

Does the voltage vary from approximately 0.95 volt with no tension applied to the sensor to approximately 3.8 volts with full tension applied to the sensor?

Yes	No
REMOVE the fused jumper wires. Go to AXB12.	REMOVE the fused jumper wires and INSTALL a new front passenger seatbelt retractor pretensioner assembly. REFER to: REFER Go to AXB14.

AXB12: CONFIRM THE OCSM FAULT

NOTE: Make sure all OCS components, SRS electrical connectors and the RCM electrical connectors are connected before carrying out the self-test. If not, Diagnostic Trouble Codes (DTCs) will be recorded.

Ignition OFF.
Prior to reconnecting any previously disconnected SRS component:
- inspect connector(s) (including any inline connectors) for pushed-out, loose or spread terminals and loose or frayed wire connections at terminals.
- inspect wire harness for any damage, pinched, cut or pierced wires.
- repair any concerns found. Refer to Connector Repair Procedures article, for schematic and connector information.
OCSM connector connected. (C3043)
Passenger Seatbelt Tension Sensor (BTS) connector connected. (if previously disconnected).
If previously directed to disconnect Passenger Side Airbag, depower the SRS. REFER to: Supplemental Restraint System article
Passenger Side Airbag Assembly connector connected. (if previously disconnected)
If previously directed to depower the SRS, repower the SRS. Do not prove out the SRS at this time. REFER to: Supplemental Restraint System article
Ignition ON, engine OFF.
Carry out the OCS self-test.
Is the original DTC retrieved on-demand during self-test?

Yes	No
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 OCS sensor. REFER to the appropriate procedure in Supplemental Restraint System article. Go to AXB14.	In the process of diagnosing the fault, the fault condition has become intermittent. Do not install any new SRS components at this time. SRS components should only be installed when directed to do so in the pinpoint test. Go to AXB13.

AXB13: CHECK FOR AN INTERMITTENT FAULT

Ignition OFF.
Passenger Seatbelt Tension Sensor (BTS) connector disconnected.
- inspect connector(s) (including any inline connectors) for loose or spread terminals and loose or frayed wire connections at terminals.
- inspect wire harness for any damage, pinched, cut or pierced wires.
- repair any concerns found. Refer to Connector Repair Procedures article, for schematic and connector information.
Passenger Seatbelt Tension Sensor (BTS) connector connected.
Ignition ON, engine OFF.
Carry out the OCS self-test.
Is DTCB0061:11, B0061:12, B0061:13, B0061:1C or B0061:49 retrieved on-demand during self-test?

Yes	No
The fault condition is now present. This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-demand during the self-test. For DTC B0061:11, Go to AXB3. For DTC B0061:12, Go to AXB6. For DTC B0061:13, Go to AXB8. For DTC B0061:1C, Go to AXB10.	CHECK for causes of the intermittent fault. ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition frequently. ACTIVATE other system in the same wire harness. Do not install any new SRS components at this time. Only install SRS components when directed to do so in the pinpoint test. REPAIR any intermittent concerns found. Go to AXB14.

AXB14: CHECK FOR ADDITIONAL SRS DIAGNOSTIC TROUBLE CODES (DTCS)

Ignition OFF.
If previously directed to disconnect Passenger Side Airbag (Inline) C339, depower the SRS. REFER to: Supplemental Restraint System article
Reconnect all SRS components (if previously disconnected).
If previously directed to depower the SRS, repower the SRS. Do not prove out the SRS at this time. REFER to: Supplemental Restraint System article
Ignition ON, engine OFF.
Carry out the RCM self-test.
If equipped with an OCSM, carry out the OCSM self-test.
Carry out the OCS self-test.
If equipped with an BECMB, carry out the BECMB self-test.
Carry out the BECMB self-test.
Are any RCM, OCSM and/or BECM-B Diagnostic Trouble Codes (DTCs) retrieved on-demand during self-test?

Yes	No
Do not clear any Diagnostic Trouble Codes (DTCs) until all Diagnostic Trouble Codes (DTCs) have been resolved. REFER to the appropriate procedure in Supplemental Restraint System article.	The repair is complete. RETURN the vehicle to the customer.