No Left Front Impact Sensor Communication

NO LEFT FRONT IMPACT SENSOR COMMUNICATION





For a complete wiring diagram Consult Diagrams/Electrical.

Theory of Operation

The Occupant Restraint Controller (ORC) supplies power to and communicates continuously with each impact sensor via each sensor's signal circuit. The power supply also enables each sensor's self-diagnostic capabilities. When powered up, the ORC establishes communication with each sensor by sending and receiving acknowledgement messages. The repair of this fault condition centers on confirming wiring, sensor, and module condition.

- When Monitored:
The Occupant Restraint Controller (ORC) supplies power to and communicates continuously with each impact sensor via each sensor's signal circuit.

- Set Condition:
The ORC will set this DTC if the ORC is unable to either establish or maintain communication with the Left Front Impact Sensor.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Restraints System Pre-Diagnostic Procedure

Diagnostic Test

1. DETERMINE ACTIVE OR STORED DTC
NOTE: Ensure that the battery is fully charged.

Turn the ignition on.
With the scan tool, read the active ORC DTC.
Does the scan tool display an active: NO LEFT FRONT IMPACT SENSOR COMMUNICATION DTC?

Yes

- Go To2

No

- Perform *RESTRAINTS SYSTEM INTERMITTENT TEST. Restraints System Intermittent Test.

2. CHECK THE LEFT FRONT IMPACT SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE




WARNING: To avoid serious or fatal injury, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

Disconnect the ORC connectors.
Disconnect the Left Front Impact Sensor connector.

NOTE: Check connectors - Clean and repair as necessary.

WARNING: To avoid serious or fatal injury, turn the ignition on, then reconnect the battery.

Measure the voltage of the Left Front Impact Sensor Signal circuit between the Left Front Impact Sensor connector and ground.
Is there any voltage present?

Yes

- Repair or replace the Left Front Impact Sensor Signal circuit for a short to voltage.
- Perform *RESTRAINTS SYSTEM VERIFICATION TEST. Verification Tests

No

- Go To 3

3. CHECK THE LEFT FRONT IMPACT SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND




WARNING: To avoid serious or fatal injury, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

Measure the resistance of the Left Front Impact Sensor Signal circuit between ground and the Left Front Impact Sensor connector cavity 2.
Is the resistance below 100k ohms?

Yes

- Repair or replace the Left Front Impact Sensor Signal circuit for a short to ground.
- Perform *RESTRAINTS SYSTEM VERIFICATION TEST. Verification Tests

No

- Go To 4

4. CHECK THE LEFT FRONT IMPACT SENSOR SIGNAL CIRCUIT FOR A SHORT TO THE LEFT FRONT IMPACT SENSOR GROUND CIRCUIT




Measure the resistance between the Left Front Impact Sensor Signal circuit and the Left Front Impact Sensor Ground circuit at the Left Front Impact Sensor connector.
Is the resistance below 100k ohms?

Yes

- Repair or replace the Left Front Impact Sensor Signal circuit for a short to the Left Front Impact Sensor Ground circuit.
- Perform *RESTRAINTS SYSTEM VERIFICATION TEST. Verification Tests

No

- Go To 5

5. CHECK THE LEFT FRONT IMPACT SENSOR SIGNAL CIRCUIT FOR AN OPEN




Connect the appropriate Load Tool 8443-25 Adaptor to the ORC connectors.
Measure the resistance of the Left Front Impact Sensor Signal circuit between the Left Front Impact Sensor connector cavity 2 and the Load Tool 8443-25 Adaptor cavity C1 (24)-10.
Is the resistance below 1.0 ohm?

Yes

- Go To 6

No

- Repair or replace the Left Front Impact Sensor Signal circuit for an open or high resistance.
- Perform *RESTRAINTS SYSTEM VERIFICATION TEST. Verification Tests

6. CHECK THE LEFT FRONT IMPACT SENSOR GROUND CIRCUIT FOR AN OPEN




Measure the resistance of the Left Front Impact Sensor Ground circuit between the Left Front Impact Sensor connector cavity 1 and the Load Tool 8443-25 Adaptor cavity C1 (24)-9.
Is the resistance below 1.0 ohm?

Yes

- Go To 7

No

- Repair or replace the Left Front Impact Sensor Ground circuit for an open or high resistance.
- Perform *RESTRAINTS SYSTEM VERIFICATION TEST. Verification Tests

7. REPLACE THE LEFT FRONT IMPACT SENSOR AND THEN CHECK FOR ACTIVE DTC
Replace the Left Front Impact Sensor.
Remove any special tools or jumper wires and reconnect all previously disconnected components - except the Battery.

WARNING: To avoid serious or fatal injury, turn the ignition on, then reconnect the battery.

With the scan tool, erase all DTC in all Restraint System Modules.
Turn the Ignition off, wait 15 seconds, then turn the Ignition on.
Wait one minute before proceeding.
With the scan tool, read active ORC DTC.
Does the scan tool display: NO LEFT FRONT IMPACT SENSOR COMMUNICATION?

Yes

WARNING: If the Occupant Restraint Controller (ORC) is dropped at any time, it must be replaced. Failure to take the proper precautions could result in accidental airbag deployment and serious or fatal injury.

WARNING: To avoid serious or fatal injury, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

- Replace the ORC.
- Perform *RESTRAINTS SYSTEM VERIFICATION TEST. Verification Tests

No

- Perform *RESTRAINTS SYSTEM VERIFICATION TEST. Verification Tests