SAAB WIS ONLINE

B1333

B1333

Airbag driver, resistance too low

The reference resistor is available in two versions. A newer, part no. 86 12 095 , and an older, part no. 84 71 153 . The new type has closer tolerance limits and should be used for more reliable diagnosis. The illustrations in the following chapter show the older type of reference resistor.


















Diagnostic procedure


1. Connect the diagnostic tool. Note the diagnostic trouble code and type of fault.


P=permanent fault, I=intermittent fault.

If the fault is permanent:

Go to point 3.

If the fault is intermittent:

Go to point 2.

2. The fault is intermittent. Try to provoke the fault at each test section in the continued fault diagnosis.

Move the connectors and cables and turn the steering wheel while testing.

Important

If no fault can be shown while testing, the contact roller should be changed. The contact roller is the most common cause for intermittent faults.


Go to point 3.

3. Turn off the ignition and remove the negative cable from the battery. Undo the bolts securing the steering wheel airbag. Unplug the connector from the back of the airbag and connect the reference resistor 84 71 153 to the connector.


On cars with airbag on passenger side;

3.a. Remove the glove-box and unplug the connector on the back of the passenger airbag.

3.b. Connect the Reference resistor 84 71 153 to the connector.

Go to point 4.

4. Refit the negative cable to the battery and turn on the ignition. Clear the fault codes. Turn off the ignition and turn it on again, wait for at least 10 seconds with the ignition on.


Check to see if the diagnostic trouble code returns.

If the diagnostic trouble code returns:

Go to point 6.

If the diagnostic trouble code does not return:

The fault lies in the airbag. Carry out an extra check as described in point 5.

5. Turn off the ignition and remove the negative cable on the battery. Remove the reference resistor from the airbag connector and connect the airbag.


Refit the negative cable on the battery and turn on the ignition. Wait for at least 10 seconds with the ignition on.

Check to see if the diagnostic trouble code returns.

If the diagnostic trouble code returns:

Turn off the ignition and remove the negative cable on the battery. Change the steering wheel airbag. Then go to point 8.

If the diagnostic trouble code does not return:

Turn off the ignition and remove the negative cable on the battery. Unplug the connector from the airbag and refit the reference resistor. Refit the negative cable on the battery and then go on to point 6.

6. Turn off the ignition. Unplug the connector from the SRS control module and connect a BOB to the wiring harness. Unplug connector H2-52. Connect an ohmmeter between connections 10 and 11 on BOB. The ohmmeter should indicate infinite resistance.


If the value is OK:

Go to point 7.

If the value differs:

There is short-circuiting in the wiring harness between connector H2-52 and the connector to the SRS control module. Locate the cause and change the wiring harness. Then go to point 8.


7. Change the contact roller. Fit a reference resistor to the connector for the steering wheel airbag. Put the connector H2-52 together and put the connector back on the SRS control module.


Switch on the ignition and clear the diagnostic trouble code. Switch the ignition off and on again, wait for at least 10 seconds and then check to see whether the diagnostic trouble code returns.

If the diagnostic trouble code returns:

Go to section: Procedure for replacing the control module .

If the diagnostic trouble code does not return:

The fault was in the contact roller. Go on to point 8.

8. Turn off the ignition and remove the negative cable on the battery. Remove the reference resistor and plug in all the connectors to their original components. Reconnect the negative cable on the battery and turn on the ignition.


Clear the diagnostic trouble code. Turn off the ignition and turn it on again. Wait for at least 10 seconds.

Check to see if the diagnostic trouble code returns.

If the diagnostic trouble code returns:

Go to section: Procedure for replacing the control module .

If the diagnostic trouble code does not return:

Restore the car.