U0172

U0172-LOST COMMUNICATION W/LEFT SIDE SATELLITE ACCELERATION SENSOR 1





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

- When Monitored:
The Occupant Restraint Controller (ORC) continuously communicates with the Left Side Impact Sensor 1 over the sensor signal circuit. The sensor communication and on board diagnostics are powered by the ORC signal.

- Set Condition:
This code will set, if the ORC and the Left Side Impact Sensor 1 do not establish and maintain valid data communications.





1. VERIFY THAT DTC U0172-LOST COMMUNICATION W/LEFT SIDE SATELLITE ACCELERATION SENSOR 1 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: U0172-LOST COMMUNICATION W/LEFT SIDE SATELLITE ACCELERATION SENSOR 1?

Yes

- Go To 2

No

- Perform the AIRBAG SYSTEM INTERMITTENT TEST. Airbag System Verification Test.

2. CHECK THE (R13) AND (R15) LEFT SIDE IMPACT SENSOR 1 CIRCUITS FOR A SHORT TO BATTERY





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 Left Side Impact Sensor 1 connector.
2. Disconnect the ORC connectors.
3. Connect the SRS Load Tool Adaptor 8443-25 to the ORC C2 connector.

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.

4. Measure the voltage of the (R13) Left Side Impact Sensor 1 Signal circuit cavity 4 and (R15) Sensor 1 Ground circuit cavity 3 between the Left Side Impact Sensor 1 connector and ground.

Is there any voltage present?

Yes

- Repair the (R13) and (R15) Left Side Impact Sensor 1 circuits for a short to battery.
- Perform the AIRBAG SYSTEM VERIFICATION TEST. Airbag System Verification Test.

No

- Go To 3

3. CHECK THE (R13) AND (R15) LEFT SIDE IMPACT SENSOR 1 CIRCUITS FOR A SHORT TO GROUND





WARNING: Turn the ignition on, then reconnect 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 (R13) Left Side Impact Sensor 1 Signal circuit cavity 4 between the Left Side Impact Sensor 1 connector and ground.
2. Measure the resistance of the (R15) Left Side Impact Sensor 1 Ground circuit cavity 3 between the Left Side Impact Sensor 1 connector and ground.

Is the resistance below 100K Ohms on either circuit?

Yes

- Repair the (R13) and (R15) Left Side Impact Sensor 1 Signal and Ground circuit for a short to ground.
- Perform the AIRBAG SYSTEM VERIFICATION TEST.Airbag System Verification Test.

No

- Go To 4

4. CHECK THE (R13) AND (R15) LEFT SIDE IMPACT SENSOR 1 CIRCUITS FOR A SHORT TOGETHER




1. Measure the resistance between the (R13) Left Side Impact Sensor 1 Signal cavity 4 and (R15) Sensor 1 Ground circuit cavity 3 at the Left Side Impact Sensor 1 connector.

Is the resistance below 100K Ohms?

Yes

- Repair the (R13) and (R15) Left Side Impact Sensor 1 circuits shorted together.
- Perform the AIRBAG SYSTEM VERIFICATION TEST. Airbag System Verification Test.

No

- Go To 5

5. CHECK THE (R15) LEFT SIDE IMPACT SENSOR 1 GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE




1. Measure the resistance of the (R15) Left Side Impact Sensor 1 Ground circuit between the Left Side Impact Sensor 1 connector cavity 3 and the SRS Load Tool Adaptor 8443-25 cavity 32-31.

Is the resistance below 1 Ohm?

Yes

- Go To 6

No

- Repair the (R15) Left Side Impact Sensor 1 Ground circuit for an open or high resistance.
- Perform the AIRBAG SYSTEM VERIFICATION TEST. Airbag System Verification Test.

6. CHECK THE (R13) LEFT SIDE IMPACT SENSOR 1 CIRCUIT FOR AN OPEN OR HIGH RESISTANCE




1. Measure the resistance of the (R13) Left Side Impact Sensor 1 Signal circuit between the Left Side Impact Sensor 1 connector cavity 4 and the SRS Load Tool Adaptor 8443-25 cavity 32-32.

Is the resistance below 1 Ohm?

Yes

- Go To 7

No

- Repair the (R13) Left Side Impact Sensor 1 Signal circuit for an open or high resistance.
- Perform the AIRBAG SYSTEM VERIFICATION TEST. Airbag System Verification Test.

7. CHECK OPERATION OF THE LEFT SIDE IMPACT SENSOR 1
1. Replace the Left Side Impact Sensor 1.
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.

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.

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 Left Side Impact Sensor 1 DTC return?

Yes

- Go To 8

No

- Repair is complete.
- Perform the AIRBAG SYSTEM VERIFICATION TEST. Airbag System Verification Test.

8. REPLACE THE OCCUPANT RESTRAINT CONTROLLER

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.

WARNING: If the airbag control module 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.

If there are no possible causes remaining, view repair.

Repair

- Replace the Occupant Restraint Controller.
- Perform the AIRBAG SYSTEM VERIFICATION TEST. Airbag System Verification Test.