B0061:1C

Diagnostic Routine Z

Diagnostic Overview

B0061:11, B0061:12, B0061:13, B0061:1C, and B0061:49

Refer to Wiring Diagram Set 46 for schematic and connector information Electrical Diagrams.

The BTS (Belt Tension Sensor) operates in conjunction with the OCS (Occupant Classification System). The OCS (Occupant Classification System) interprets a variable voltage signal provided by the BTS (Belt Tension Sensor) to identify the possible presence of a child safety seat in the front passenger seat. The voltage output of the BTS (Belt Tension Sensor) is proportional to the amount of tension applied to the sensor by the belt: no belt tension causes a low voltage (approximately 0.95 volt) to be output, and high belt tension causes a high voltage (approximately 3.8 volts) to be returned to the OCSM (Occupant Classification System Module).

The OCSM (Occupant Classification System Module) monitors the BTS (Belt Tension Sensor) and related circuits for the following faults:

- Resistance out of range

- Unexpected voltage

- Short to ground

- Faulted BTS (Belt Tension Sensor) (part of front passenger safety belt)

If a fault is detected, the OCSM (Occupant Classification System Module) stores DTC (Diagnostic Trouble Code) B0061:11, B0061:12, B0061:13, B0061:1C or B0061:49 in memory and sends a message to the RCM (Restraints Control Module) over the HS-CAN (High Speed Controller Area Network) indicating that an OCS (Occupant Classification System) fault is present. Upon receipt of this message, the RCM (Restraints Control Module) sets DTC (Diagnostic Trouble Code) B00A0:09 and sends a message over the HS-CAN (High Speed Controller Area Network) to the IPC (Instrument Panel Cluster) to illuminate the air bag warning indicator.

DTC Fault Trigger Conditions

Visual Inspection and Diagnostic Pre-checks

- Inspect for a damaged passenger safety belt or BTS (Belt Tension Sensor)

- Inspect for a damaged passenger seat cushion wiring harness

- Inspect for a loose or damaged OCSM (Occupant Classification System Module) or BTS (Belt Tension Sensor) connector

- Inspect for a damaged OCSM (Occupant Classification System Module)

Pinpoint Test

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 air bag, Safety Canopy(R) 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: 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 (Supplemental Restraint System) components when instructed to do so within a pinpoint test step. Failure to follow this instruction may result in incorrect diagnosis of the SRS (Supplemental Restraint System).

NOTE: Always make sure the correct SRS (Supplemental Restraint System) 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 Catalog Advantage or equivalent to make sure the correct component is being installed. If an incorrect SRS (Supplemental Restraint System) component is installed, DTCs (Diagnostic Trouble Codes) may set.

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

1. RETRIEVE OCSM (Occupant Classification System Module) DTCs (Diagnostic Trouble Codes)

1. Ignition ON.

2. Using a scan tool, perform OCSM (Occupant Classification System Module) self-test to retrieve DTCs (Diagnostic Trouble Codes).

Was DTC (Diagnostic Trouble Code) B0061:11, B0061:12, B0061:13, B0061:1C or B0061:49 retrieved on-demand during self-test?

2. CHECK THE BTS (Belt Tension Sensor)

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

1. Ignition OFF.

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.

2. Disconnect Passenger Safety BTS (Belt Tension Sensor) C3238.

3. Using a scan tool, perform OCSM (Occupant Classification System Module) self-test to retrieve DTCs (Diagnostic Trouble Codes).

4. DIAGNOSTIC TIP: When viewing DTCs (Diagnostic Trouble Codes) with the BTS (Belt Tension Sensor) disconnected, an open circuit fault is normally retrieved.

Was DTC (Diagnostic Trouble Code) B0061:11 retrieved on-demand during self-test?

3. CHECK THE BTS (Belt Tension Sensor) CIRCUITS FOR A SHORT TO GROUND

1. Ignition OFF.

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.

2. Disconnect OCSM (Occupant Classification System Module) C3159.

3. Measure:

4. Measure:

Are the resistances greater than 10,000 ohms?

4. CHECK THE BTS (Belt Tension Sensor) VREF CIRCUIT FOR AN OPEN

1. Measure:

Is the resistance less than 0.5 ohm?

5. CHECK THE BTS (Belt Tension Sensor) SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE

1. Ignition OFF.

2. Depower the SRS (Supplemental Restraint System). REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

3. Disconnect Passenger Seat Side Air Bag Module (Inline) C339.

4. Disconnect Passenger Safety BTS (Belt Tension Sensor) C3238.

5. Disconnect OCSM (Occupant Classification System Module) C3159.

6. Repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) at this time. REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

7. Ignition ON.

8. Measure:

Is any voltage present?

6. CHECK THE BTS (Belt Tension Sensor) GROUND CIRCUIT FOR AN OPEN

1. Ignition OFF.

2. Measure:

Is the resistance less than 3 ohms?

7. CHECK THE BTS (Belt Tension Sensor)

NOTE: This pinpoint test step will attempt to change the fault reported by the OCSM (Occupant Classification System Module) by inducing a different fault condition. If the fault reported changes, this indicates the OCSM (Occupant Classification System Module) is functioning correctly and is not the source of the fault.

1. Ignition OFF.

2. Depower the SRS (Supplemental Restraint System). REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

3. Disconnect Passenger Seat Side Air Bag Module (Inline) C339.

4. Disconnect Passenger Safety BTS (Belt Tension Sensor) C3238.

5. Connect a fused jumper wire:

6. Repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) at this time. REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

7. Ignition ON.

8. Using a scan tool, perform OCSM (Occupant Classification System Module) self-test to retrieve DTCs (Diagnostic Trouble Codes).

9. DIAGNOSTIC TIP: When viewing DTCs (Diagnostic Trouble Codes) with the BTS (Belt Tension Sensor) circuits shorted together, a short to ground fault is normally retrieved.

Did the on-demand DTC (Diagnostic Trouble Code) change from B0061:13 to B0061:11?

8. CHECK THE BTS (Belt Tension Sensor) SIGNAL CIRCUIT FOR AN OPEN

1. Ignition OFF.

2. Disconnect OCSM (Occupant Classification System Module) C3159.

3. Measure:

Is the resistance less than 0.5 ohm?

9. CHECK THE BTS (Belt Tension Sensor) SIGNAL CIRCUIT FOR A SHORT TO THE BTS (Belt Tension Sensor) VREF CIRCUIT

1. Ignition OFF.

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.

2. Disconnect OCSM (Occupant Classification System Module) C3159.

3. Disconnect Passenger Safety BTS (Belt Tension Sensor) C3238.

4. Measure:

Is the resistance greater than 10,000 ohms?

10. CHECK BTS (Belt Tension Sensor) VOLTAGE OUTPUT

1. Ignition OFF.

2. Depower the SRS (Supplemental Restraint System). REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

3. Connect OCSM (Occupant Classification System Module) C3159.

4. Disconnect Passenger Seat Side Air Bag Module (Inline) C339.

5. Connect fused jumper wires:

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?

11. CONFIRM THE OCSM (Occupant Classification System Module) FAULT

NOTE: Make sure all OCS (Occupant Classification System) system components, SRS (Supplemental Restraint System) electrical connectors and the RCM (Restraints Control Module) electrical connectors are connected before carrying out the self-test. If not, DTCs (Diagnostic Trouble Codes) will be recorded.

1. Ignition OFF.

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.

2. Prior to reconnecting any previously disconnected SRS (Supplemental Restraint System) 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 Wiring Diagram Set 5 for schematic and connector information Electrical Diagrams.

3. Connect OCSM (Occupant Classification System Module) C3159 (if previously disconnected).

4. Connect Passenger Safety BTS (Belt Tension Sensor) C3238 (if previously disconnected).

5. If previously directed to depower the SRS (Supplemental Restraint System), repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) at this time. REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

6. Ignition ON.

7. Using a scan tool, perform OCSM (Occupant Classification System Module) self-test to retrieve DTCs (Diagnostic Trouble Codes).

Was the original DTC (Diagnostic Trouble Code) retrieved on-demand during self-test?

12. CHECK FOR AN INTERMITTENT FAULT

1. Ignition OFF.

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.

2. Disconnect Passenger Safety BTS (Belt Tension Sensor) C3238:

- 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 Wiring Diagram Set 5 for schematic and connector information Electrical Diagrams.

3. Connect Passenger Safety BTS (Belt Tension Sensor) C3238.

4. Ignition ON.

5. Using a scan tool, perform OCSM (Occupant Classification System Module) self-test to retrieve DTCs (Diagnostic Trouble Codes).

Was DTC (Diagnostic Trouble Code) B0061:11, B0061:12, B0061:13, B0061:1A or B0061:1C retrieved on-demand during self-test?

13. CHECK FOR ADDITIONAL SRS (Supplemental Restraint System) DTCs (Diagnostic Trouble Codes)

1. Ignition OFF.

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.

2. Reconnect all SRS (Supplemental Restraint System) components (if previously disconnected).

3. If previously directed to depower the SRS (Supplemental Restraint System), repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) at this time. REFER to Supplemental Restraint System (SRS) Depowering and Repowering - with Intelligent Access (IA) or REFER to Supplemental Restraint System (SRS) Depowering and Repowering - without Intelligent Access (IA) .

4. Ignition ON.

5. Using a scan tool, perform Restraints self-test to retrieve DTCs (Diagnostic Trouble Codes).

NOTE: When selecting Restraints from the Self Test menu, DTCs (Diagnostic Trouble Codes) are retrieved from the RCM (Restraints Control Module) and OCSM (Occupant Classification System Module).

Are any RCM (Restraints Control Module) and/or OCSM (Occupant Classification System Module) DTCs (Diagnostic Trouble Codes) retrieved?