U0170 Lost Communication W/UP Front Left Satellite Acceleration Sensor

Wiring U0170 code

U0170 code - 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 sensors internal circuitry and software validity.

When monitored this DTC the Occupant Restraint Controller (ORC) continuously communicates with the front left impact sensor over the sensor signal circuit. The sensor communication and on board diagnostics are powered by the ORC signal. Set condition this DTC this code will set, if the ORC and the front left impact sensor do not establish and maintain valid data communication.

Possible causes U0170 code:

- Signal circuit shorted to battery

- Signal circuit shorted to ground

- Front left impact sensor circuits shorted together

- Front left impact sensor ground circuit open

- Front left impact sensor signal circuit open

- Occupant Restraint Controller (ORC)

Diagnostic test U0170 code

Step 1. Verify that DTC U0170

Turn the ignition off disconnect the 12volt battery and wait two minutes before proceeding. Using the wiring diagram/schematic as a guide check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension. If after the harness inspection it appears the impact sensor connector is only seated halfway. Reseat the harness connector into the impact sensor and lock the tab.

Turn the ignition on, then reconnect the 12volt battery and wait two minutes before proceeding. Make sure the battery is fully charged.

Does the scan tool display active U0170?

Yes, go to step 2.

No, go to step 9.

Step 2. Check the (R79) and (R81) front left impact sensor signal and ground circuits for a short to battery

Turn the ignition off, disconnect the 12volt battery and wait two minutes before proceeding.

Disconnect the front left impact sensor harness connector. Disconnect the ORC harness connectors. Connect the SRS load tool adaptor 8443-32-L to the ORC harness connectors. The IP harness is always connected to the right side of the adaptor 8443-32-L

Turn the ignition on the front left impact sensor signal circuit and the front left impact sensor ground circuit at the front left impact sensor harness connector.

Is there any voltage present?

Yes, turn the ignition off, disconnect battery and wait two minutes before proceeding. Repair the (R79) and (R81) front left impact sensor circuits for a short to battery. Perform the Airbag system verification.

No, go to step 3.

Step 3. Check the (R79) and (R81) front left impact sensor circuits for a short to ground

Turn the ignition off, disconnect the 12 volt battery and wait two minutes before proceeding. Measure the resistance between ground and the (R79) front left impact sensor signal circuit and (R81) front left impact sensor ground circuit at the front left impact sensor harness connector.

Is the resistance below 100k Ohms?

Yes, repair the (R79) and (R81) front left impact sensor circuits for a short to ground

No, go to step 4.

Step 4. Check the (R79) and (R81) front left impact sensor circuits for a short together

Measure the resistance between the (R79) front left impact sensor signal circuit and the (R81) front left impact sensor ground circuit at the front left impact sensor harness connector.

Is the resistance below 100k Ohms?

Yes, repair the (R79) and (R81) front left impact sensor circuits shorted together.

No, go to step 5.

Step 5. Check the (R81) front left impact sensor ground circuit for an open or high resistance

Measure the resistance of the (R81) front left impact sensor ground circuit between the front left impact sensor harness connector and the SRS load tool adaptor 8443-32-L

Is the resistance below 1 Ohms?

Yes, go to step 6.

No, repair the (R81) front left impact sensor 1 ground circuit for an open or high resistance.

Step 6. Check the (R79) front left impact sensor circuit for an open or high tesistance

Measure the resistance of the (R79) front left impact sensor signal circuit between the front left impact sensor harness connector and the SRS load tool adaptor 8443-32-L

Is the resistance below 1 Ohms?

Yes, go to step 7.

No, repair the front left impact sensor signal circuit for an open or high resistance.

Step 7. Check operation of the front left impact sensor

Replace the front left impact sensor. Reconnect the vehicle body harness to the impact sensor. Remove any special tools or jumper wires and reconnect all previously disconnected components - except the battery.

Turn the ignition on, then reconnect the 12 volt battery and wait two minutes before proceeding.

Connect the scan tool to the data link connector-use the most current software available. Use the scan tool and erase the stored codes in all airbag system modules. Turn the ignition off, and wait 15 seconds before turning the ignition on. 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 step 8

No, repair is complete.

Step 8. Replace the Occupant Restraint Controller

Turn the ignition off, disconnect the 12volt battery and wait two minutes before proceeding. Disconnect the SRS load tool adaptor.

Repair, if the Occupant Restraint Controller (ORC) is dropped at any time, it must be replaced.

Replace the ORC/SRS module, perform the Airbag system verification.

Step 9. Test for an intermittent condition