U0173
U0173-LOST COMMUNICATION W/LEFT SIDE SATELLITE ACCELERATION SENSOR 2
For a complete wiring diagram refer to the Wiring Information. Electrical Diagrams
Theory of Operation
The impact sensors perform their own self-test using power supplied by the Occupant Restraint Controller (ORC) then communicates this status back to the ORC with periodic updates. The repair of this fault condition involves verifying the integrity of the wiring between the ORC and the sensor.
- When Monitored:
The Occupant Restraint Controller (ORC) continuously communicates with the Left Side Impact Sensor 2 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 2 do not establish and maintain valid data communications.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Restraints System Pre-Diagnostic Procedure.
1. VERIFY THAT DTC U0173-LOST COMMUNICATION W/LEFT SIDE SATELLITE ACCELERATION SENSOR 2 IS ACTIVE
NOTE: Ensure the battery is fully charged.
1. Turn the ignition on.
2. With the scan tool, read ORC DTCs.
Does the scan tool display active: U0173-LOST COMMUNICATION W/LEFT SIDE SATELLITE ACCELERATION SENSOR 1?
Yes
- Go To 2
No
- Perform the RESTRAINTS SYSTEM INTERMITTENT TEST.. Restraints System Intermittent Condition Test
2. CHECK THE (R17, R19) LEFT SIDE IMPACT SENSOR 2 SIGNAL AND GROUND 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 2 connector.
2. Disconnect the ORC C1 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.
3. Measure the voltage of the (R17) Left Side Impact Sensor 2 Signal circuit and (R19) Sensor Ground circuit at the Left Side Impact Sensor 2 connector and ground.
Is there any voltage present?
Yes
- Repair the (R17, R19) Left Side Impact Sensor 2 circuits for a short to battery.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.
No
- Go To 3
3. CHECK THE (R17) LEFT SIDE IMPACT SENSOR 2 SIGNAL CIRCUIT FOR A SHORT TO GROUND
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. Measure the resistance of the (R17) Left Side Impact Sensor 2 Signal circuit between the Left Side Impact Sensor 2 connector and ground.
Is the resistance below 100K Ohms?
Yes
- Repair the (R17) Left Side Impact Sensor 2 Signal circuit for a short to ground.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.
No
- Go To 4
4. CHECK THE (R17, R19) LEFT SIDE IMPACT SENSOR 2 CIRCUITS FOR A SHORT TOGETHER
1. Measure the resistance between the (R17) Left Side Impact Sensor 2 Signal and (R19) Sensor Ground circuits at the Left Side Impact Sensor 2 connector.
Is the resistance below 100K Ohms?
Yes
- Repair the (R17, R19) Left Side Impact Sensor 2 circuits shorted together.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.
No
- Go To 5
5. CHECK THE (R19) LEFT SIDE IMPACT SENSOR 2 GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Connect the SRS Load Tool Kit 8443 to the ORC C1 connector.
2. Measure the resistance of the (R19) Left Side Impact Sensor 2 Ground circuit between the Left Side Impact Sensor 2 connector and the SRS Load Tool Kit 8443.
Is the resistance below 1 ohm?
Yes
- Go To 6
No
- Repair the (R19) Left Side Impact Sensor 2 Ground circuit for an open or high resistance.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.
6. CHECK THE (R17) LEFT SIDE IMPACT SENSOR 2 CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (R17) Left Side Impact Sensor 2 Signal circuit between the Left Side Impact Sensor 2 connector and the SRS Load Tool Kit 8443.
Is the resistance below 1 ohm?
Yes
- Go To 7
No
- Repair the (R17) Left Side Impact Sensor 2 Signal circuit for an open or high resistance.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.
7. CHECK OPERATION OF THE LEFT SIDE IMPACT SENSOR 2
1. Replace the Left Side Impact Sensor 2.
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 2 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 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 Occupant Restraint Controller (ORC) is dropped at any time, it must be replaced. Failure to follow these instructions may result in possible serious or fatal injury.
If there are no possible causes remaining, view repair.
Repair
- Replace the Occupant Restraint Controller.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.