DTC 21 - Electric Detonator 1 Short to Ground

MALFUNCTION
DTC 21 L: Electric detonator 1, shorting to ground

DIAGNOSTIC PROCEDURE
1. Unscrew the steering wheel center pad (airbag module) and unplug the connector at the rear of the airbag.
2. Plug reference resistor 84 71 153 into the connector.
3. Clear the trouble code and wait at least 40 seconds with the ignition switched ON. Check whether the trouble code persists. If it persists - proceed to step 4.
4. If the trouble code has been cleared, the fault could be in the airbag. Check this by removing the reference resistor and plugging in the airbag. Switch ON the ignition and wait at least 40 seconds.
If the trouble code is generated afresh, the fault is in the steering wheel center pad (airbag module). Change the airbag module. Unplug connector 59 and plug test cable 84 71 146 into the connector. (The reference resistor should be plugged in.)
5. Use an ohmmeter to measure the resistance across one pin and ground and across the other pin and ground. Turn the steering wheel from full lock to full lock a few times during each measurement.
If all readings are higher than 5,700 ohms - proceed to step 9.
If any reading is 5,700 ohms or lower - proceed to step 6.
6. Unplug connector 335 and plug the test cable into the connector.
7. Use an ohmmeter to measure the resistance across one pin and ground and across the other pin and ground. Turn the steering wheel from full lock to full lock a few times during each measurement.
If both resistance readings are higher than 5,700 ohms, the fault could be in the wiring between connectors 59 and 335.
8. Investigate the cause. Rectify the fault or change the wiring as necessary.
If any reading is 5,700 ohms or lower, the fault is in the contact unit. Change the contact unit.
9. The fault could be in the wiring between connector 59 and the control module. Investigate the cause. Rectify the fault or change the control module as necessary. Before changing the control module, Programming and Relearning