B1C1A

B1C1A-PASSENGER ACTIVE HEADREST CONTROL CIRCUIT OPEN

For a complete wiring diagram, refer to the Wiring Information.

Special Tools:

Theory of Operation

The Passenger Active Headrest signal circuit is driven by a solenoid that also uses a diode in parallel. The single electrical component of the AHR (Active Headrest) unit is the latch-release solenoid. The solenoid is connected by a 2 way pigtail wire and harness connector. The pigtail wire and 2 way connector are routed through the center of one of the headrest support posts and down through the guide sleeve to the interior of the seat back, where it connects to the seat wire harness. The solenoid is grounded at an independent dedicated ground. The AHR components itself cannot be repaired. If damaged or ineffective, the AHR (Active Headrest) must be replaced as a new assembly. If upon inspection the AHR has deployed it can be reset following the proper reset method. Also if the already deployed Driver or Passenger AHR are latched in the locked position please see the scan tool miscellaneous functions to set the latch in the unlock or deployed position. Please be very observant and careful, the scan tool should never be used to actually deploy a known good non-deployed Driver or Passenger AHR.

- When Monitored:

The Occupant Restraint Controller (ORC) continuously communicates with the Passenger Head Restraint over the Passenger Head Restraint Solenoid Signal circuit. The Passenger Head Restraint communication and on board diagnostics are powered by the ORC signal.

- Set Condition:

This code will set, if the ORC detects an Open circuit on the (R677) Passenger Head Restraint Solenoid Signal circuit.

Possible Causes:

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview

1. VERIFY ACTIVE DTC

NOTE: Make sure the battery is fully charged.

1. Turn the ignition on.
2. With the scan tool, read the ORC DTCs

Does the scan tool display active B1C1A-PASSENGER ACTIVE HEAD RESTRAINT CONTROL CIRCUIT OPEN DTC?

Yes

- Go To 2

No

- Perform the AIRBAG SYSTEM INTERMITTENT TEST. Initial Inspection and Diagnostic Overview.

2. CHECK FOR A SHORTED OR OPEN ACTIVE HEAD REST CIRCUIT IN PASSENGER ACTIVE HEAD REST

WARNING: Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

1. Access the Passenger Active Head Rest harness connector located in the passenger seatback jumper harness.
2. Disconnect the Passenger Active Headrest harness connectors.

NOTE: Check the connectors - Clean and repair as necessary.

NOTE: Please use the Active Head Rest Load Tool 10253 in testing the present status of the AHR signal circuit.

3. Connect the 10253 AHR Load Tool to the passenger AHR seatback jumper harness connector going into the seatback and under the seat.

WARNING: Turn the ignition on, then reconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

4. With the scan tool, read the active ORC DTCs.

Does the scan tool display: B1C1A-PASSENGER ACTIVE HEADREST CONTROL CIRCUIT OPEN DTC?

Yes

- Go To 3

No

- WARNING: Turn the ignition off disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
- Replace the Passenger Active Head Rest.

3. CHECK THE (R677) ACTIVE HEAD RESTRAINT 1ST ROW PASSENGER SIGNAL CIRCUIT FOR A SHORT TO GROUND

1. Measure the resistance of the (R677) Passenger Head Restraint 1st Row Signal circuit between the Active Head Restraint 1st Row Passenger harness connector and the appropriate terminal of the SRS Load Tool Adapter 8443-25.

Is the resistance below 1 Ohm?

Yes

- Go To 5

No

- Repair the (R677) Passenger Head Restraint Solenoid Signal circuit for an open or high resistance.
- Perform the AIRBAG SYSTEM VERIFICATION TEST. Airbag System Verification Test.

5. CHECK THE PASSENGER ACTIVE HEAD REST (Z914) GROUND CIRCUIT FOR AN OPEN

WARNING: Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

1. Measure the resistance between ground and the (Z919) Active Head Restraint 1st Row Passenger Ground circuit at the Active Head Restraint 1st Row Passenger connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 6

No

- Repair the Ground circuit for a open or high resistance.
- Perform the AIRBAG SYSTEM VERIFICATION TEST. Airbag System Verification Test.

6. CHECK OPERATION OF THE PASSENGER ACTIVE HEAD RESTRAINT

1. Replace the Passenger Active Head Restraint.
2. Reconnect the vehicle body harness to the Passenger Head Restraint connector.
3. Remove any special tools or jumper wires and reconnect all previously disconnected components - except the Battery.

WARNING: Turn the ignition on, then reconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

4. Connect the scan tool to the Data Link Connector - use the most current software available.
5. Use the scan tool and erase the ORC stored codes.
6. Turn the Ignition Off and wait 15 seconds before turning the Ignition On.
7. Wait one minute and read active codes and if there are none present read the stored codes.

Does the scan tool display active B1C1A-PASSENGER ACTIVE HEADREST CONTROL CIRCUIT OPEN DTC?

Yes

- WARNING: Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
- WARNING: If the Occupant Restraint Controller (ORC) is dropped at any time, it must be replaced. Failure to follow these instructions may result in possible serious or fatal injury.

- Replace the ORC.
- Perform the AIRBAG SYSTEM VERIFICATION TEST. Airbag System Verification Test.

No

- Repair is complete.
- Perform the AIRBAG SYSTEM VERIFICATION TEST. Airbag System Verification Test.