B1C12
B1C12 - Driver Active Headrest Control Circuit Low
For a complete wiring diagram, refer to.
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 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 Passenger Active Headrest during the start up phase of the ORC module. The Passenger Active Headrest communication and on board diagnostics are powered by the ORC signal.
• Set Condition: This DTC will set, if the ORC detects low voltage on the Active Head Restraint 1st Row Passenger Signal circuit (R677).
Always perform the Pre - Diagnostic Troubleshooting procedure before proceeding.
Test Step 1 - Check For Active DTC
• Ensure the battery is fully charged.
• Turn the ignition ON.
• With the scan tool, read all active ORC DTCs.
Is the DTC active?
Yes
• Go to Test Step 2 => [ Test Step 2 - Check
for a Shorted Active Head Rest Circuit in Driver Active Head Rest ]
No
• Perform the Restraints System Intermittent Test. Refer to => Non - DTC Based Diagnostics. ORC Restraints System Intermittent Test
Test Step 2 - Check for a Shorted Active Head Rest Circuit in Driver Active Head Rest
• Please use the Active Head Rest Load Tool 10253 in testing the present status of the AHR signal circuit.
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.
• Access the Driver Active Head Rest harness connector located in the driver seatback jumper harness.
• Disconnect the Driver Active Headrest harness connectors.
• Check the connectors - Clean and repair as necessary.
• Please use the Active Head Rest Load Tool 10253 in testing the present status of the AHR signal circuit.
• Connect the AHR Load Tool to the driver AHR seatback jumper harness connector going into the seatback and under the seat.
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.
• With the scan tool, read the active ORC DTCs.
Is the DTC active?
Yes
• Go to Test Step 3 => [ Test Step 3 - Check
the Active Head Restraint 1st Row Driver Signal Circuit (R676) for
a Short to Ground ]
No
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.
Test Step 3 - Check the Active Head Restraint 1st Row Driver Signal Circuit (R676) for a Short to Ground
• The AHR connectors carry a shorting bar that should set a high code upon disconnecting the AHR connectors.
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.
• Access the Driver Active Headrest connector located in the driver seat back.
• Disconnect the Driver Active Headrest harness connector.
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.
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.
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.
• 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 Test Step 4 => [ Test Step 4 - Check
the Active Head Restraint 1st Row Driver Signal Circuit (R676) for
a Short to Ground in the Driver Active Head Rest Seat Back Jumper
Harness ]
Test Step 4 - Check the Active Head Restraint 1st Row Driver Signal Circuit (R676) for a Short to Ground in the Driver Active Head Rest Seat Back Jumper Harness
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.
• Inspect for damaged or bent terminals at the C313 underseat jumper harness connector. Reconnect the C313 connector.
• Reconnect the C313 underseat harness connector.
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
• Go to Test Step 5 => [ Test Step 5 - Check
the Active Head Restraint 1st Row Driver Signal Circuit (R676) Harness
for a Short to Ground in the Body Harness ]
No
• Repair the short to ground in the Active Head Restraint 1st Row Driver Signal circuit (R676) between the C313 underseat harness connector and the Driver Active Headrest harness connector in the seat back.
• Perform the Restraints System Intermittent Test. Refer to => Non - DTC Based Diagnostics. ORC Restraints System Intermittent Test
Test Step 5 - Check the Active Head Restraint 1st Row Driver Signal Circuit (R676) Harness for a Short to Ground in the Body Harness
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.
• Access the Occupant Restraint Controller Module in the center stack area just below the radio.
• Disconnect the ORC Module C2 harness connector.
• Connect the SRS Load Tool Adapter 8443-28.
• Keep the C313 underseat jumper harness connector disconnected.
• 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 8443-28.
Is the resistance below 5.0 Ohms?
Yes
• Repair the short to ground in the Active Head Restraint 1st Row Driver Signal circuit (R676) located between the C313 underseat jumper harness connector and the ORC.
• Perform the Restraints System Intermittent Test. Refer to => Non - DTC Based Diagnostics. ORC Restraints System Intermittent Test
No
• Go to Test Step 6 => [ Test Step 6 - Check
the Operation of the Driver Active Headrest ]
Test Step 6 - Check the Operation of the Driver Active Headrest
• Reconnect any previously disconnected harness connectors.
• Remove any special tools or jumper wires and reconnect all previously disconnected components - except the Battery.
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.
• Connect the scan tool to the Data Link Connector - use the most current software available.
• Use the scan tool and erase the ORC stored codes.
• Turn the Ignition Off and wait 15 seconds before turning the Ignition On.
• Wait one minute and read active codes and if there are none present read the stored codes.
Is the DTC active?
Yes
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.
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 Restraints System Intermittent Test. Refer to => Non - DTC Based Diagnostics. ORC Restraints System Intermittent Test
No
• Repair complete. Verify reconnecting of all components and inlines.
• Perform the Restraints System Intermittent Test. Refer to => Non - DTC Based Diagnostics. ORC Restraints System Intermittent Test