Volt

DTC B0085 or B0088

The impact sensors are equipped on vehicles to supplement the supplemental inflatable restraint (SIR) system performance. The impact sensors are electronic and are not part of the deployment loops, but instead provide inputs to the sensing and diagnostic module (SDM). The impact sensors can assist in determining the severity of some frontal and side collisions. The SDM uses the input from the impact sensors to assist in determining the severity of a collision further supporting air bag deployment. If the SDM determines a deployment is warranted, the SDM will cause current to flow through the deployment loops deploying the air bags.

Ignition voltage is between 9-16 V.

Any of the following conditions exist for 10 seconds:

B0085 02, B0088 02

B0085 05, B0088 05

B0085 39, B0088 39

B0085 3A, B0088 3A

B0085 71, B0088 71

The SDM has received invalid serial data from the sensor.

The SDM requests the instrument panel cluster to illuminate the AIR BAG indicator.

Schematic Reference

SIR Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

SIR System Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Note: Refer to SIR Service Precautions

Note: The connector and connector position assurance (CPA) may seat independently of each other. Both the connector and CPA should seat with an audible and/or tactile click. The CPA isolates the shorting-bars within the connector allowing the deployment circuit to operate properly. Replace any CPA that is damaged or missing.

1. Verify that DTC B0085 or B0088 symptom byte 39 or 71 is not set as current.

⇒	If DTC B0085 or B0088 symptom byte 39 or 71 is set as current

Replace the sensor listed below:

•	B0085 - B63LF side impact sensor-left front

•	B0088 - B63RR side impact sensor-right rear

⇓	If DTC B0085 or B0088 symptom byte 39 or 71 is not set as current

2. Verify that DTC B0085 or B0088 symptom byte 3A is not set as current.

⇒	If DTC B0085 or B0088 symptom byte 3A is set as current

Replace the incorrect B63 side impact sensor

⇓	If DTC B0085 or B0088 symptom byte 3A is not set as current

3. Verify that DTC B0085 or B0088 symptom byte 02 or 05 is set as current.

⇒	If only DTC B0085 symptom byte 02 or 05 is set as current

Refer to Circuit/System Testing - Only DTC B0085 or B0088 is set.

⇒	If only DTC B0088 symptom byte 02 or 05 is set as current

Refer to Circuit/System Testing - Only DTC B0085 or B0088 is set.

⇒	If both DTC B0085 or B0088 symptom byte 02 or 05 is set as current

Refer to Circuit/System Testing - Both DTC B0085 and B0088 are set.

⇓	If DTC B0085 or B0088 symptom byte 02 or 05 is not set as current

4. All OK.

Note: The signal circuit is shared at the K36 SDM between the B63LF side impact sensor left front and the B63RR side impact sensor right rear (DTC B0085 and DTC B0088). Therefore a short to ground or short to voltage in either of these signal circuits can set a DTC for both circuits, and an open in either circuit should only set its corresponding DTC.

Only DTC B0085 or B0088 is set

1. Vehicle OFF, disconnect the harness connector at the appropriate B63 side impact sensor. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 Ω between the low reference circuit terminal 2 and ground.

⇒	If 10 Ω or greater

2.1.	Disconnect the X2 harness connector at the K36 SDM.

2.2.	Test for less than 2 Ω in the low reference circuit end to end.

⇒	If 2 Ω or greater, repair the open/high resistance in the circuit.

⇒	If less than 2 Ω, replace the K36 SDM.

⇓	If less than 10 Ω

3. Disconnect the X2 harness connector at the K36 SDM.
4. Test for less than 2 Ω between the signal circuit terminal 1 at the B63 side impact sensor and the K36 SDM terminal listed below:

•	Left front signal terminal 19 X2

•	Right rear signal terminal 30 X2

⇒	If 2 Ω or greater

Repair the open/high resistance in the circuit.

⇓	If less than 2 Ω

5. Verify that the K36 SDM calibrations match the VIN data, software part number, and calibration part number.

⇒	If the K36 SDM calibrations do not match the VIN data

Program the K36 SDM, refer to Inflatable Restraint Sensing and Diagnostic Module Programming and Setup .

⇓	If the K36 SDM calibrations match the VIN data

6. Replace the B63 side impact sensor.
7. Verify the DTC does not set.

⇒	If the DTC sets

Replace the K36 SDM.

⇓	If the DTC does not set

8. All OK

Both DTC B0085 and B0088 are set

1. Vehicle OFF. Disconnect the X2 harness connector at the K36 SDM. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 1 V between the signal circuit terminals listed below and ground:

•	Left front signal circuit - terminal 19 X2

•	Right rear signal circuit - terminal 30 X2

⇒	If 1 V or greater

2.1.	Disconnect the harness connector at the B63 side impact sensor that failed the test.

2.2.	Test for less than 1 V between signal circuit and ground.

⇒	If 1 V or greater, repair the short to voltage in the circuit.

⇒	If less than 1 V, replace the B63 side impact sensor.

⇓	If less than 1 V

3. Test for greater than 50k Ω between each signal circuit listed below and ground:

•	Left front signal circuit - terminal 19 X2

•	Right rear signal circuit - terminal 30 X2

⇒	If 50k Ω or less

3.1.	Disconnect the harness connector at the B63 side impact sensor that failed the test.

3.2.	Test for infinite resistance between the signal circuit and ground.

⇒	If less than infinite resistance, repair the short to ground on the circuit.

⇒	If infinite resistance, replace the B63 side impact sensor.

⇓	If greater than 50k Ω

4. Verify that the K36 SDM calibrations match the VIN data, software part number, and calibration part number.

⇒	If the K36 SDM calibrations do not match the VIN data

Program the K36 SDM, refer to Inflatable Restraint Sensing and Diagnostic Module Programming and Setup .

⇓	If the K36 SDM calibrations match the VIN data

5. Replace the K36 SDM.

Perform the Diagnostic Repair Verification after completing the repair.