B0090-49

B0090-49-LEFT FRONTAL RESTRAINTS SENSOR - INTERNAL ELECTRONIC FAILURE

Special Tools:










For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The left front impact sensor is located in the engine compartment. Impact Sensors perform their own self test using power supplied by the Occupant Restraint Controller (ORC) then communicate this status back to the module. The repair of this fault centers on verifying the integrity of the sensor's internal circuitry and software validity.

- When Monitored:
The impact sensors perform a self test for internal circuitry at power up during the initialization process and continuously through the ignition cycle every 10 ms.

- Set Condition:
This DTC sets when the ORC receives notification of a self test failure within the impact sensor. Once set, this DTC is locked for the entire ignition cycle. The DTC has to qualify again to reset on the next ignition cycle.





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

1.

NOTE: The use of a approved special tool or Digital Multimeter such as a Fluke Meter that will not apply more than 20 milliamperes to a circuit are the only measurement tools to be used.

NOTE: Probing of the circuit cavities at the ORC Module C1-A, C1-B, or C2-A body harness connectors is only to be done with a approved test lead from the Dedicated Test Leads kit 10159, test lead 10159-6. Or a comparable test lead to prevent vehicle wiring harness connector damage during diagnostic procedures. (10159)
VERIFY THAT DTC B0090-49-LEFT FRONTAL RESTRAINTS SENSOR - INTERNAL ELECTRONIC FAILURE IS ACTIVE

NOTE: Make sure the battery is fully charged.

1. Turn the ignition on.
2. With the scan tool, read ORC DTCs.

Does the scan tool display active: B0090-49-LEFT FRONTAL RESTRAINTS SENSOR - INTERNAL ELECTRONIC FAILURE?

Yes

- Go To 2

No

- Perform the RESTRAINTS SYSTEM INTERMITTENT TEST. Restraints System Intermittent Condition Test.

2. CHECK THE (R79, R81) FRONT LEFT IMPACT SENSOR SIGNAL AND GROUND CIRCUITS FOR A SHORT TO VOLTAGE





WARNING: Turn the ignition off, disconnect the battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

1. Disconnect the Front Left Impact Sensor harness connector.
2. Disconnect the ORC harness connector.If the vehicle is equipped with the standard key ignition, follow this ignition on warning.

WARNING: Turn the ignition on, then reconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
If the vehicle is equipped with the keyless ignition, follow this ignition on warning.

WARNING: Disconnect the 12-volt battery wait two minutes before proceeding, remove the ORC fuses, connect the 12-volt battery, wait two minutes before proceeding. Cycle the ignition to the On position, then reconnect the ORC fuses. Wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

3. Measure the voltage of the (R79) Front Left Impact Sensor Signal circuit and (R81) Sensor Ground circuit at the Front Left Impact Sensor connector and ground.

Is there any voltage present?

Yes

- Repair the (R79, R81) Front Left Impact Sensor circuits for a short to voltage.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.

No

- Go To 3

3. CHECK THE (R79) FRONT LEFT IMPACT SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND





WARNING: Turn the ignition off, disconnect the battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

1. Measure the resistance of the (R79) Front Left Impact Sensor Signal circuit between the Front Left Impact Sensor connector and ground.

Is the resistance below 100K Ohms?

Yes

- Repair the (R79) Front Left Impact Sensor Signal circuit for a short to ground.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.

No

- Go To 4

4. CHECK THE (R79, R81) FRONT LEFT IMPACT SENSOR CIRCUITS FOR A SHORT TOGETHER




1. Measure the resistance between the (R79) Front Left Impact Sensor Signal and (R81) Sensor Ground circuits at the Front Left Impact Sensor harness connector.

Is the resistance below 100K Ohms?

Yes

- Repair the (R79, R81) Front Left Impact Sensor circuits shorted together.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.

No

- Go To 5

5. CHECK THE (R81) FRONT LEFT IMPACT SENSOR GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE





WARNING: Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

1. Disconnect the ORC Module body harness connector.
2. Connect the test leads to the DVOM.
3. Measure the resistance of the (R81) Front Left Impact Sensor Ground circuit between the Front Left Impact Sensor connector terminal 2 and the ORC Module body harness connector terminal C1-B 87.

Is the resistance below 1 Ohm?

Yes

- Go To 6

No

- Repair the (R81) Front Left Impact Sensor Ground circuit for an open or high resistance.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.

6. CHECK THE (R79) FRONT LEFT IMPACT SENSOR CIRCUIT FOR AN OPEN OR HIGH RESISTANCE




1. Measure the resistance of the (R79) Front Left Impact Sensor Signal circuit between the Front Left Impact Sensor connector terminal 1 and the ORC Module body harness connector terminal C1-B 88.

Is the resistance below 1 Ohm?

Yes

- Go To 7

No

- Repair the (R79) Front Left Impact Sensor Signal circuit for an open or high resistance.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.

7. CHECK OPERATION OF THE FRONT LEFT IMPACT SENSOR
1. Replace the Front Left Impact Sensor. Impact Sensor - Removal
2. Reconnect the vehicle body harness to the impact sensor.
3. Remove any special tools or jumper wires and reconnect all previously disconnected components - except the Battery.If the vehicle is equipped with the standard key ignition, follow this ignition on warning.

WARNING: Turn the ignition on, then reconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
If the vehicle is equipped with the keyless ignition, follow this ignition on warning.

WARNING: Disconnect the 12-volt battery wait two minutes before proceeding, remove the ORC fuses, connect the 12-volt battery, wait two minutes before proceeding. Cycle the ignition to the On position, then reconnect the ORC fuses. Wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

4. Connect the scan tool to the Data Link Connector - use the most current software available.
5. Use the scan tool and erase the stored codes in all airbag system modules.
6. Turn the Ignition Off, and wait 15 seconds before turning the Ignition On.
7. Wait one minute, and read active codes and if there are none present read the stored codes.

Did the active Front Left Impact Sensor DTC return?

Yes

- Go To 8

No

- Repair is complete.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.

8. REPLACE THE OCCUPANT RESTRAINT CONTROLLER

WARNING: Turn the ignition off, disconnect the battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

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. Failure to follow these instructions may result in possible serious or fatal injury.

Repair

- Replace the Occupant Restraint Controller. Occupant Restraint Controller - Removal.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.