(850-2646) Improved fault diagnosis, airbag
Symptom: B0022 - Driver frontal deployment circuit (stage 1), resistance low.
B0026 - Driver frontal deployment circuit (stage 1), resistance high.
B0042 - Driver frontal deployment circuit (stage 2), resistance low.
B0044 - Driver frontal deployment circuit (stage 2), resistance high.
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TECHNICAL SERVICE BULLETIN
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Bulletin Nbr:
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850-2646
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Date:
...........
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November 2006
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Market:
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all
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Improved fault diagnosis, airbag
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Saab 9-5 M06-
Fault diagnosis methods have been improved for the following diagnostic trouble codes: B0022, B0026, B0042 and B0044. Fault diagnosis will be updated in WIS for edition 2007-1.
In the event of the diagnostic trouble codes below, the following fault diagnosis must be carried out.
Symptom description
B0022 - Driver frontal deployment circuit (stage 1), resistance low.
B0026 - Driver frontal deployment circuit (stage 1), resistance high.
B0042 - Driver frontal deployment circuit (stage 2), resistance low.
B0044 - Driver frontal deployment circuit (stage 2), resistance high.
Not affected
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Action 1, checking the function
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1.
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Turn the ignition key to the OFF position.
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2.
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Unplug the following connectors:
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-
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Control module, Airbag (A)
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-
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Airbag, driver (B) (both connectors must be unplugged)
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3.
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B0022, B0026
: Connect the reference resistance 86 12 095 to the violet connector.
B0042, B0044
: Connect the reference resistance 86 12 095 to the yellow connector.
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4.
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Connect the breakout box/BOB to the wiring harness.
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5.
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B0022, B0026
: Measure the resistance between pin 28 and pin 29 (C).
B0042, B0044
: Measure the resistance between pin 30 and pin 31 (C).
Jiggle the wiring harness at several points and in different directions to detect intermittent open circuits and short circuits.
Also check contacts, connectors and crimps for oxidation, loose pins and pin clamping force.
The value should be 1.5 - 4.5 Ohm.
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6.
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Is the function correct?
NO
, see Action 2.
YES
, see Action 3.
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Action 2, checking the ignition circuit resistance
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1.
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Unplug the connector, contact roller, steering wheel (A).
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2.
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Diagnostic trouble code B0022, B0026
: Measure the resistance between the airbag control module pin 28 and pin 29 (C).
Diagnostic trouble code B0042, B0044
: Measure the resistance between pin 30 and pin 31 (C).
Jiggle the wiring harness at several points and in different directions to detect intermittent open circuits and short circuits. Also check contacts, connectors and crimps for oxidation, loose pins and pin clamping force.
The value should be OL.
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3.
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Is the function correct?
NO
, see Action 4.
YES
, see Action 5.
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Action 3, component replacement
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1.
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Replace the airbag, driver, in accordance with WIS - 9-5 - Body - Airbag - Adjustment/Replacement.
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2.
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Final inspection, see Action 7.
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Action 4, rectifying the cable
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1.
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Rectify the wiring harness between the airbag control module and the contact roller, steering wheel.
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2.
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Final inspection, see Action 7.
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Action 5, checking the ignition circuit resistance
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1.
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Diagnostic trouble code B0022, B0026
: Make a connection between pins 1 and 2 in the female connector (A). Use 86 12 731.
Diagnostic trouble code B0042, B0044
: Make a connection between pins 3 and 4 in the female connector (A). Use 86 12 731.
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2.
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Diagnostic trouble code B0022, B0026
: Measure the resistance between the airbag control module pin 28 and pin 29 (C).
Diagnostic trouble code B0042, B0044
: Measure the resistance between the airbag control module pin 30 and pin 31 (C).
Jiggle the wiring harness at several points and in different directions to detect intermittent open circuits and short circuits. Also check contacts, connectors and crimps for oxidation, loose pins and pin clamping force.
The value should be 0.1 Ohm.
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3.
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Is the function correct?
NO
, see Action 4.
YES
, see Action 6.
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Action 6, component replacement
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1.
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The fault is in the circuit in question.
Check the component in question with regard to open and short circuits to B+ or B- before replacing the wiring, steering wheel or contact roller, steering wheel.
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2.
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Replace the component in question.
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3.
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Final inspection, see Action 7.
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Action 7, final inspection
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1.
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Clear the diagnostic trouble codes in all systems.
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2.
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Turn the ignition key to the OFF position.
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3.
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Turn the ignition key to the ON position.
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4.
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Read the diagnostic trouble codes.
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5.
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Check that no diagnostic trouble codes have recurred.
Is the function correct?
YES
, the action taken was correct.
NO
, see Procedures before replacing the control module, in accordance with WIS - 9-5 - Body - Airbag - Fault diagnosis, general.
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Warranty/Time Information
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