Airbag DM Fault Code 32

Airbag DM Fault Code 32

Drivers airbag circuit high resistance or open circuit.

Normal Operation

The diagnostic module measures the resistance across pins 2-4 and 2-5 every time the ignition is switched on. The resistance should be 1.6 to 1.8Ω. This value is made up of the airbag 1.0Ω and the cable reel cassette windings 0.3-0.4Ω per winding. If the total resistance in the drivers airbag circuit exceeds 4.0Ω, fault code 32 will be declared and the airbag lamp will be illuminated.

Note: The resistance of the airbag simulator is 2.5Ω, therefore expect total resistance readings of 2.8 - 2.9Ω with the simulator fitted.

Caution: The drivers airbag and the cable reel cassette connectors contains shorting bars which short circuit pins 1 and 3 of the connectors when disconnected.

DO NOT REMOVE THE AIRBAG SHORTING BAR UNDER ANY CIRCUMSTANCES.

The harness shorting bars may be temporarily removed during the following resistance checks.

Possible Causes

• Excessive resistance in the cable reel cassette connections.
• Open circuit or high resistance in the cable reel cassette windings.
• Open circuit or high resistance in the wiring harness
• Open circuit or high resistance in the drivers airbag module.
• Defective diagnostic module.

WARNING: Do not attempt a direct resistance check on the airbag module. Accidental deployment can occur due to the induced voltage from the measuring equipment.

Fault Analysis

1. Disarm the airbag system and fit airbag simulators (6.4.21.4).
2. Disconnect the diagnostic module and remove the plastic wedge from connector 2 (black). Measure the resistance between pins 2-4 and 2-5. The resistance should be 2.8 - 2.9Ω.

If the resistance is 2.8 - 2.9Ω, go to step 3.

If the resistance is not in the range 2.8 - 2.9Ω, isolate the continuity problem noting the following:

1. Pin 2-4 is shorted to pin 2-5 by a shorting link when plug 2 of the diagnostic connector is removed. Removal of the plastic wedge from the plug will remove the short circuit.
2. Both halves of the cable reel connector have shorting links which will short pin 1 to pin 3 when the connection is removed. Removal of the plastic wedge from either half will remove the short circuit in that part of the wiring.
3. A shorting link is fitted in the airbag module connector. Do not attempt to remove this shorting link or the plastic wedge. Do not attempt to measure the resistance of the airbag module.
4. Carefully replace all plastic wedges on completion of the circuit checks.

3. The fault is therefore in either the airbag module or in the airbag diagnostic module.

Substitute a known good diagnostic module. If code 32 recurs with the airbag simulator fitted, there is a fault in the wiring.

If the fault code 32 does not recur, rearm the airbags (6.4.21.4) and retest.

If fault code 32 recurs with the airbag module fitted, the airbag module is faulty. Replace the drivers airbag module (4.5.01.3).