SAAB WIS ONLINE

DTC 56 ABNORMAL G SENSOR HIGH µ OUTPUT

DTC 56 ABNORMAL G SENSOR HIGH µ OUTPUT

DIAGNOSIS:

Faulty G sensor output voltage

TROUBLE SYMPTOM:

ABS does not operate.

WIRING DIAGRAM:


CHECK OUTPUT OF G SENSOR USING Vehicle Diagnostic Interface.

Select “Current data display & Save” on the Vehicle Diagnostic Interface.

Read G sensor output on the Vehicle Diagnostic Interface display.

Is the voltage −1.25 — 1.25 m/s when G sensor is in horizontal position?

Yes


No


CHECK POOR CONTACT IN CONNECTORS.

Turn the ignition switch to OFF.

Is there poor contact in connector between ABSCM&H/U and G sensor?

Yes

Repair the connector.


No


CHECK ABSCM&H/U.

Connect all connectors.

Erase the memory.

Perform the inspection mode.

Read out the DTC.

Is the same DTC as in current diagnosis still being output?

Yes

Replace the ABSCM&H/U.


No


CHECK ANY OTHER DTC APPEARANCE.

Are other DTCs being output?

Yes

Proceed with the diagnosis corresponding to DTC.


No

A temporary poor contact.


CHECK OPEN CIRCUIT IN G SENSOR OUTPUT HARNESS AND GROUND HARNESS.

Turn the ignition switch to OFF.

Disconnect the connector from ABSCM& H/U.

Measure the resistance between ABSCM&H/U connector terminals.

Connector & terminal

(B301) No. 10 — No. 21:

Is the resistance 5.0 — 5.6 kΩ?

Yes


No

Repair the harness/connector between G sensor and ABSCM&H/U.


CHECK GROUND SHORT OF HARNESS.

Measure the resistance between ABSCM&H/U connector and chassis ground.

Connector & terminal

(B301) No. 10 — Chassis ground:

Is the resistance more than 1 MΩ?

Yes


No

• Repair the harness between G sensor and ABSCM&H/U.

• Replace the ABSCM&H/U.


CHECK G SENSOR.

Remove the console box.

Remove the G sensor from vehicle.

Connect the connector to G sensor.

Connect the connector to ABSCM&H/U.

Turn the ignition switch to ON.

Measure the voltage between G sensor connector terminals.

Connector & terminal

(B292) No. 2 (+) — No. 3 (−):

Is the voltage 2.1 — 2.5 V when G sensor is in horizontal position?

Yes


No

Replace the G sensor.


CHECK G SENSOR.

Measure the voltage between G sensor connector terminals.

Connector & terminal

(B292) No. 2 (+) — No. 3 (−):

Is the voltage 3.7 — 4.1 V when G sensor is inclined forwards to 90°?

Yes


No

Replace the G sensor.


CHECK G SENSOR.

Measure the voltage between G sensor connector terminals.

Connector & terminal

(B292) No. 2 (+) — No. 3 (−):

Is the voltage 0.5 — 0.9 V when G sensor is inclined backwards to 90°?

Yes


No

Replace the G sensor.


CHECK ABSCM&H/U.

Turn the ignition switch to OFF.

Connect all connectors.

Erase the memory.

Perform the inspection mode.

Read out the DTC.

Is the same DTC as in current diagnosis still being output?

Yes

Replace the ABSCM&H/U.


No


CHECK ANY OTHER DTC APPEARANCE.

Are other DTCs being output?

Yes

Proceed with the diagnosis corresponding to DTC.


No

A temporary poor contact.