B1C19

Symptoms

• The security system malfunction lamp (SRS/Airbag) is on on the instrument panel.
• No headrest activation during system testing
• Clicking or grinding noises in the passenger headrest area
• Visible signs of corrosion or damage to the wires at the headrest
• Power failure in the passenger seat power supply system

Causes

• Short circuit in the headrest control circuit harness
• Damaged or burnt out active head restraint solenoid connector
• Malfunction of the system control solenoid valve (solenoid)
• Corrosion of contacts in the electrical control circuit
• Voltage surge in the on-board network or generator malfunction
• Incorrect installation or reconnection of wiring harness after repair
• Malfunction of the airbag control unit (ECU/PCM)
• Damage to the insulation of the headrest control circuit wires
• Moisture or humidity getting into electrical connectors

How to Fix

1. Connect the OBD-II diagnostic scanner and check for code B1C19, check for additional error codes
2. Visually inspect the active passenger head restraint control circuit harness and connectors for damage, corrosion, or looseness.
3. Check the voltage in the control circuit using a multimeter - it should be within 4.5-5.5V (depending on the model)
4. Disconnect the active head restraint solenoid connector and check for continuity, corrosion or oxidation.
5. Measure the solenoid resistance (usually 30-70 ohms depending on the car model)
6. If the solenoid is faulty, replace the active head restraint solenoid valve with a new original element.
7. Check and, if necessary, reconnect the wiring harness, clean the oxidized contacts with contact cleaner
8. Clear the error code using a scanner and perform a test drive to check that the code does not reappear
9. Check the functionality of the active head restraint system through diagnostics (if provided by the scanner functions)

Related codes

FAQ