B2862

Side Airbag, Driver





Fault symptoms
Airbag warning lamp on.

Conditions
The following conditions are applicable to the respective diagnostic trouble codes:

B2861
- The voltage applied to control module pin 2 is lower than 1.5 V for 1.25 s.

B2862
- The voltage applied to control module pin 1 is higher than 3.5 V for 1.25 s.

B2863
- The resistance measured by the control module is higher than 3.90 ohms for 10 s.
- The resistance measured by the control module is higher than 225 ohms for 160 ms.
- Fault diagnosis will not be carried out if diagnostic trouble code B2861 or B2862 has been generated.

B2864
- The resistance measured by the control module is lower than 1.50 ohms for 20 s.
- Fault diagnosis will not be carried out if diagnostic trouble code B2861 or B2862 has been generated.

Action

1. Check the wiring harness between the control module and the driver's side airbag




- Turn the ignition switch to the OFF position.
- Check the wiring's 29-pin connector for an open circuit and/or pin slide-out and rectify it as necessary.




- Connect the reference resistor 86 12 335 to the 29-pin female connector.




- Undo the connector: Control Module Airbag: (331)
- Check pins 10 and 11 for an open circuit and/or pin slide-out and rectify them as necessary.
- Connect a break-out box (BOB) to the mains.
- Select the trouble code that has been generated

B2863,B2864
- Go to step 2.
B2861,B2862
- Go to step 3.

2. Check the wiring harness between the control module and the driver's side airbag
- Take a resistance reading




- Red feed cable: Control module Airbag: 10
- Black feed cable: Control module Airbag: 11
- The value should be 2 - 4 ohms

Test results OK?

YES
- Change: Side airbag, driver
- Go to step 5.
NO
- Repair or replace the wiring.
- Go to step 5.

3. Check the wiring harness between the control module and the driver's side airbag
- Take a resistance reading




- Red feed cable: Control module Airbag: 10




- Black test lead: Car battery: B-.
- The resistance should be infinite (O.L.).

Test results OK?

YES
- Go to step4.
NO
- Repair or replace the wiring.
- Go to step5.

4. Check the wiring harness between the control module and the driver's side airbag
- Take a resistance reading




- Red feed cable: Control module Airbag: 11




- Black test lead: Car battery: B-.
- The resistance should be infinite (O.L.).

Test results OK?

YES
- Change: Side airbag, driver
- Go to step 5.
NO
- Repair or replace the wiring.
- Go to step 5.

5. Final check




- Clear the diagnostic trouble codes in all systems.
- Perform a driving cycle:
- Drive the car with varying engine loads and at varying engine speeds for five minutes.
- Evaluate the driving cycle:




- Check that the diagnostic trouble code has not recurred.

Test results OK?

YES
- The steps taken to rectify the fault were correct.
NO
- See Before Changing A Control Module.