B1C12
B1C12-DRIVER ACTIVE HEADREST CONTROL CIRCUIT LOW
For a complete wiring diagram, refer to the Wiring Information.
Special Tools:
Theory of Operation
The Driver 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) monitors the Driver Active Headrest during the start up phase of the ORC module. The Driver Head Restraint communication and on board diagnostics are powered by the ORC signal.
- Set Condition:
This code will set, if the ORC detects low voltage on the (R676) Driver Head Restraint Solenoid Signal circuit or a circuit low message from the Driver Head Restraint sends.
Possible Causes:
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 B1C12-DRIVER ACTIVE HEADREST CONTROL CIRCUIT LOW 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: B1C12-DRIVER ACTIVE HEADREST CONTROL CIRCUIT LOW?
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 Driver Active Head Rest.
3. CHECK THE (R676) ACTIVE HEAD RESTRAINT 1ST ROW DRIVER SIGNAL CIRCUIT HARNESS FOR A SHORT TO GROUND
NOTE: The AHR connectors carry a shorting bar that should set a high code upon disconnecting the AHR harness connectors.
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 Driver Active Headrest connector located in the passenger seat back.
2. Disconnect the Driver Active Headrest harness connector.
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.
Does the scan tool display active B1C13-DRIVER ACTIVE HEADREST CONTROL CIRCUIT HIGH?
Yes
- Turn the ignition off.
- 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.
- Connect the Driver Active Headrest harness connector.
- 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.
- Wait 15 seconds before turning the Ignition On.
- Use the scan tool and erase the ORC stored codes.
- NOTE: This puts the ORC module into a reset diagnostic mode to check for active DTCs.
- Turn the ignition off. Wait 15 seconds before turning the Ignition On.
- Wait one minute and read active codes.
- If the B1C12-Driver Active Headrest Control circuit Low DTC becomes active, replace the Driver Active Headrest.
No
- Go To 4
4. CHECK THE (R676) ACTIVE HEAD RESTRAINT 1ST ROW DRIVER SIGNAL CIRCUIT HARNESS FOR A SHORT TO GROUND IN THE DRIVER ACTIVE HEAD REST SEAT BACK JUMPER HARNESS
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.
NOTE: Inspect for damaged or bent terminals at the inline underseat jumper harness connectors located under the driver seat to the driver active head rest. Disconnect the inline harness connector.
1. Disconnect the ORC harness connector.
2. Connect the SRS Load Tool Adapter 8443-25.
3. Reconnect the inline underseat harness connector.
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.
Does the scan tool display active B1C12-DRIVER ACTIVE HEADREST CONTROL CIRCUIT LOW?
Yes
- Repair the short to ground in the (R676) Active Head Restraint 1st Row Driver Signal circuit between the in-line underseat harness connector and the Driver ACtive Headrest harness connector in the seat back.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Verification Tests
No
- Go To 5
5. CHECK THE (R676) ACTIVE HEAD RESTRAINT 1ST ROW DRIVER SIGNAL CIRCUIT HARNESS FOR SHORT TO GROUND IN THE BODY HARNESS
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 Occupant Restraint Controller Module in the center stack area just below the radio.
2. Disconnect the ORC Module C2 harness connector.
3. Connect the SRS Load Tool Adapter 8443-25.
4. Keep the in-line underseat jumper harness connector disconnected.
5. Measure the resistance between ground and the (R676) Active Head Restraint 1st Row Driver Signal circuit of the appropriate terminal of the SRS Load Tool Adapter 8443-25.
Is the resistance below 5.0 Ohm?
Yes
- Repair the short to ground in the (R676) Active Head Restraint 1st Row Driver Signal circuit located between the inline underseat jumper harness connector (body side) and the ORC.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Verification Tests
No
- Go To 6
6. CHECK THE (Z913) ACTIVE HEAD RESTRAINT 1ST ROW DRIVER GROUND CIRCUIT FOR OPEN
1. Measure the resistance of the Ground circuit between the Active Head Restraint 1st Row Driver connector cavity 1 and ground.
Is the resistance below 5.0 Ohms?
Yes
- Go To 7
No
- Repair the Ground circuit for an open or high resistance.
- Perform the AIRBAG SYSTEM VERIFICATION TEST. Airbag System Verification Test.
7. CHECK THE (R676) DRIVER HEAD RESTRAINT 1ST ROW DRIVER SIGNAL CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (R676) Active Head Restraint 1st Row Driver Signal circuit between the Driver Head Restraint connector cavity 2 and the SRS Load Tool Adapter 8443-25 cavity 32-18.
Is the resistance below 1 Ohm?
Yes
- Go To 8
No
- Repair the (R676) Active Head Restraint 1st Row Driver Signal circuit for an open or high resistance.
- Perform the AIRBAG SYSTEM VERIFICATION TEST. Airbag System Verification Test.
8. CHECK OPERATION OF THE DRIVER ACTIVE HEAD REST
1. Replace the Driver Active Head Rest.
2. Reconnect the vehicle body harness to the Driver 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 B1C12-DRIVER ACTIVE HEADREST CONTROL CIRCUIT LOW 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.