Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC B0085 00: LF Side Impact SensorDTC B0085 0F: LF Side Impact Sensor Erratic
DTC B0085 39: LF Side Impact Sensor Internal Electronic Failure
DTC B0085 3A: LF Side Impact Sensor Incorrect Component Installed
DTC B0086 00: RF Side Impact Sensor
DTC B0086 0F: RF Side Impact Sensor Erratic
DTC B0086 39: RF Side Impact Sensor Internal Electronic Failure
DTC B0086 3A: RF Side Impact Sensor Incorrect Component Installed
DTC B0087 00: LR Side Impact Sensor
DTC B0087 0F: LR Side Impact Sensor Erratic
DTC B0087 39: LR Side Impact Sensor Internal Electronic Failure
DTC B0087 3A: LR Side Impact Sensor Incorrect Component Installed
DTC B0088 00: RR Side Impact Sensor
DTC B0088 0F: RR Side Impact Sensor Erratic
DTC B0088 39: RR Side Impact Sensor Internal Electronic Failure
DTC B0088 3A: RR Side Impact Sensor Incorrect Component Installed
Diagnostic Fault Information
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
|---|---|---|---|---|---|
Left Front Side Impact Sensor High Signal | B0085 00 | B0085 0F | B0085 00 | B0085 00 | B0085 0F |
Left Front Side Impact Low Reference | B0085 00 | B0085 0F | B0085 00 | B0085 00 | B0085 0F |
Right Front Side Impact Sensor High Signal | B0086 00 | B0086 0F | B0086 00 | B0086 00 | B0086 0F |
Right Front Side Impact Low Reference | B0086 00 | B0086 0F | B0086 00 | B0086 00 | B0086 0F |
Left Rear Side Impact Sensor High Signal | B0087 00 | B0087 0F | B0087 00 | B0087 00 | B0087 0F |
Left Rear Side Impact Low Reference | B0087 00 | B0087 0F | B0087 00 | B0087 00 | B0087 0F |
Right Rear Side Impact Sensor High Signal | B0088 00 | B0088 0F | B0088 00 | B0088 00 | B0088 0F |
Right Rear Side Impact Low Reference | B0088 00 | B0088 0F | B0088 00 | B0088 00 | B0088 0F |
Circuit/System Description
The inflatable restraint front end sensor utilizes a unidirectional 2-wire circuit. The front end sensor modulates current on the interface to send ID, state of health, and deployment commands to the inflatable restraint sensing and diagnostic module (SDM). The SDM serves as a power source and a ground for the front end sensor. When the ignition is turned ON and input power from the SDM is first detected, the front end sensor responds by performing internal diagnostics and sending an ID to the SDM. The SDM considers the ID to be valid if the response time is less than 5 seconds. The front end sensor continually communicates status messages to the SDM, which determines if a fault is present in the front end sensor circuit. When a fault is detected, the SDM may reset the front end sensor up to 2 times by removing and reapplying power to it. If the fault is still present, the SDM will set a DTC.
Conditions for Running the DTC
Ignition voltage is between 9-16 volts.
Conditions for Setting the DTC
Any of the following conditions exist:
B0085 00, B0086 00, B0087 00, B0088 00
| • | The front end sensor has been shorted to voltage, open, or shorted to ground. |
| • | The front end sensor current has been above 23 mA for greater than 5 milliseconds. |
| • | The SDM has not received a message from the front end sensor for more than 375 milliseconds. |
B0085 0F, B0086 0F, B0087 0F, B0088 0F
The SDM has received erratic messages from the front end sensor.
B0085 39, B0086 39, B0087 39, B0088 39
| • | The SDM has received a Not Ok (NOK) message from the front end sensor. |
| • | The SDM has not received a message. |
| • | The SDM has received invalid serial data from the front end sensor. |
B0085 3A, B0086 3A, B0087 3A, B0088 3A
| • | The SDM has received an ID message from the front end sensor, which does not match the ID stored in the SDM memory. |
| • | The SDM has reset the front end sensor twice without detecting the correct ID message. |
B0085 71, B0086 71, B0087 71, B0088 71
The SDM has received invalid serial data from the front end sensor.
Action Taken When the DTC Sets
| • | The SDM requests the instrument panel cluster (IPC) to illuminate the AIR BAG indicator. |
| • | The SIR system is disabled and no deployments are allowed. |
Conditions for Clearing the DTC
| • | The condition for setting the DTC no longer exists. |
| • | A history DTC will clear once 100 malfunction-free ignition cycles have occurred. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
SIR System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the appropriate impact sensor and the SDM.
- Ignition ON, test for less than 1 volt between the signal circuit terminal B and ground.
- Ignition ON, test for less than 1 volt between the low reference circuit terminal A and ground.
- Test for infinite resistance between the signal circuit terminal B and ground.
- Test for less than 1 ohm between the signal circuit terminal B at the impact sensor and the appropriate SDM harness connector terminal listed below:
- Test for less than 1 ohm between the low reference circuit terminal A at the impact sensor and the appropriate SDM harness connector terminal listed below:
- If all circuits test normal, test or replace the appropriate sensor.
- Reconnect all SIR components. Ignition ON, verify the DTC is not set as current.
Important: Refer to SIR Service Precautions.
When removing connectors, inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector:| • | Side impact sensors |
| • | SDM module |
| • | Side impact sensor wiring harness connectors |
| • | SDM wiring harness connector |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. |
| ⇒ | If greater than the specified range, test the low reference circuit for a short to voltage. |
| ⇒ | If less than the specified value, test the signal circuit for a short to ground. |
| • | Right front side impact sensor - terminal 43. |
| • | Left front side impact sensor - terminal 42. |
| • | Right rear side impact sensor - terminal 45. |
| • | Left rear side impact sensor - terminal 44. |
| ⇒ | If greater than the specified range, test the signal circuit for an open/high resistance. |
| • | Right front side impact sensor - terminal 41. |
| • | Left front side impact sensor - terminal 40. |
| • | Right rear side impact sensor - terminal 47. |
| • | Left rear side impact sensor - terminal 46. |
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. |
| ⇒ | If the DTC resets as current, replace the SDM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for SDM replacement, setup, and programming |
