Airbag DM Fault Code 41

Airbag DM Fault Code 41

Right hand crash sensor feed or return open circuit.

Normal Operation

The diagnostic module constantly measures the voltage at pins 1-2 and 1-11. The voltage should be 10±1 volt. The two wires are connected together within the right hand crash sensor. If the voltage at 1-2 falls below that at 1-11, an open circuit has occurred. Fault code 41 will be declared and the airbag lamp will be illuminated.

Possible Causes

• Open circuit in the wires from diagnostic module pins 1-2 or 1-11 to the right hand crash sensor.
• An open circuit within the right hand crash sensor across pins 1 and 2 of the sensor connector.

Fault Analysis

1. Disarm the airbag system and fit airbag simulators (6.4.21.4).
2. Disconnect the diagnostic module and check continuity between pins 1-2 and 1-11.
   If the resistance is significantly greater than 0Ω, go to step 3.

If the circuit resistance is 0Ω, the fault is intermittent. Manipulate the harness, particularly in the area of the sensor connector and the crash sensor harness to bulkhead harness connector, to identify the location of the open circuit. Service the circuit as necessary.

3. Check the right hand crash sensor connector for security and service the connector if necessary.
   If the connector is secure, disconnect and check continuity from pin 1 to pin 2 of the sensor.
   If the resistance is high or an open circuit is detected, replace the crash sensor.
   If the sensor continuity is good (0Ω), service the crash sensor loom or bulkhead harness as necessary to remove the high resistance or open circuit.
4. With the airbag simulators in circuit and all connectors in place, clear the code 41. Switch off and then on again to check that the airbag warning lamp comes on at 'ignition on' and extinguishes after approximately six seconds.
5. Switch off and rearm the airbags (6.4.21.4)

Airbag DM Fault Code 42

Left hand crash sensor feed or return open circuit.

Normal Operation

The diagnostic module constantly measures the voltage at pins 1-6 and 1-12. The voltage should be 10±1 volt. The two wires are connected together within the left hand crash sensor. If the voltage at 1-6 falls below that at 1-12, an open circuit has occurred. Fault code 42 will be declared and the airbag lamp will be illuminated.

Possible Causes

• Open circuit in the wires from diagnostic module pins 1-6 or 1-12 to the left hand crash sensor.
• An open circuit within the left hand crash sensor across pins 1 and 2 of the sensor connector.

Fault Analysis

1. Disarm the airbag system and fit airbag simulators (6.4.21.4).
2. Disconnect the diagnostic module and check continuity between pins 1-6 and 1-12.
   If the resistance is significantly greater than 0Ω, go to step 3.

If the circuit resistance is 0Ω, the fault is intermittent. Manipulate the harness, particularly in the area of the sensor connector and the crash sensor harness to bulkhead harness connector, to identify the location of the open circuit. Service the circuit as necessary.

3. Check the left hand crash sensor connector for security and service the connector if necessary.
   If the connector is secure, disconnect and check continuity from pin 1 to pin 2 of the sensor.
   If the resistance is high or an open circuit is detected, replace the crash sensor.
   If the sensor continuity is good (0Ω), service the crash sensor harness or bulkhead harness as necessary to remove the high resistance or open circuit.
4. With the airbag simulators in circuit and all connectors in place, clear the code 42. Switch off and then on again to check that the airbag warning lamp comes on at 'ignition on' and extinguishes after approximately six seconds.
5. Switch off and rearm the airbags (6.4.21.4).