DTC 43A31 - Electric Detonator 1 Short Circuit

MALFUNCTION
Diagnostic trouble code 43A31: Electric detonator 1, short circuit.

DIAGNOSTIC PROCEDURE
1. Unscrew the steering wheel airbag module and unplug the connector at the rear of the airbag. Plug reference resistor 84 71 153 into the connector.

NOTE: For cars with an airbag on the passenger 5 side: Remove the lower cover and unplug the passenger airbag connector H2-80. Plug reference resistor 84 71 153 via cable 86 11 378 into the connector.

2. Switch ON the ignition and clear the trouble code. Switch the ignition OFF and then ON again. Wait at least 40 seconds with the ignition ON. Check whether the trouble code recurs.
If the trouble code recurs, proceed to step 3. If the trouble code does not recur, the fault is in the steering wheel airbag module, Switch OFF the ignition and carry out a double check by plugging in the airbag. Switch ON the ignition and wait at least 40 seconds with the ignition ON. Check whether the trouble code recurs.
If the trouble code recurs, switch OFF the ignition and change the airbag. Switch ON the ignition and clear the trouble code. Switch the ignition OFF and then ON again. Wait at least 40 seconds with the ignition ON. Check whether the trouble code recurs.
3. Unplug the connector at control module 331 and plug breakout box 86 11 006 into the connector ON the wiring.
4. Unplug connector H2-52 and measure the resistance across pins 17 and 18 ON the breakout box.
If the resistance is low, the fault is in the wiring between connector H2-52 and the connector at the control module. Investigate the cause. Rectify the fault or change the wiring as necessary.
If the resistance is high, proceed to step 7.
If the part number of the control module is 41 76 368, the trouble code might be generated because the plastic pins in the control module connector do not open the short-circuiting contacts when the connector is plugged in.
5. Try fitting a new control module, part No. 44 33 298.
6. Clear the trouble code and wait at least 40 seconds with the ignition ON. Then check whether the trouble code recurs.
If the trouble code does not recur, the fault was in the control module connector.
If the trouble code does recur, proceed to step 7.
7. Change the contact unit, connect the steering wheel airbag and plug in connector H2-52 . Also plug the connector into control module 331.
8. Clear the trouble code and wait at least 40 seconds with the ignition ON. Then check whether the trouble code recurs.
If the trouble code does not recur, the fault was in the contact unit.
If the trouble code does recurs, the fault is in the steering wheel airbag module. Change the airbag module