SIR Side Impact Sensor (SIS) adopts one way 2-lined circuit. The side impact sensor modulates the interface current, sends the ID number, operation status and deployment command to the SIR SDM. The SDM provides the side impact sensor with power and ground. With ignition ON, the side impact sensor detects the power provided by the SDM for the first time, it will conduct internal diagnosis and send ID to the SDM as response. If the responsive time is less than 5 seconds, the SDM will take it as valid number. The side impact sensor sends the status messages continuously to the SDM, which in turn determines if the side impact sensor circuit is in trouble or not. When fault is detected, the SDM will reset the side impact sensor power through disconnecting and reconnecting. If the fault still exists, the SDM will set a DTC.
The diagnostic procedure supports the following DTC:
DTC B0085 Left Front - Driver Side Impact Sensor
The vehicle has DTCs including the DTC symptoms. Refer to DTC Symptom Description for DTC information.
DTC Symptom | DTC Symptom Descriptor |
---|---|
01 | Short to battery |
02 | Short to ground |
04 | Open circuit |
39 | Internal electronic fault |
71 | Invalid serial data received |
0F | Side impact sensor unstable |
3A | Component installed incorrectly |
Ignition 1 voltage is within normal operating range.
All the following conditions last for 2.5 seconds:
• | Side impact sensor is short to voltage. |
• | The SDM fails to receive message from the side impact sensor for more than 375 milliseconds. |
• | Side impact sensor is short to ground. |
• | Side impact sensor current is more than 23 mA for more than 5 milliseconds. |
Side impact sensor circuit is open.
• | The SDM receives NOK message from the side impact sensor. |
• | The SDM fails to receive message. |
The SDM receives invalid serial data from the side impact sensor.
The SDM receives unstable message from the side impact sensor.
• | The SDM receives ID message from side impact sensor, however, the ID does not match the ID information in the SDM memory. |
• | The SDM resets the side impact sensor twice and still fails to detect the correct ID information. |
The SDM commands the AIR BAG indicator ON via GMLAN serial data communications.
• | When conditions for the DTC to set no longer exist, use CLEAR DTC function of the scan tool to clear the DTC. |
• | After 255 consecutive warm-up cycles without failure, the DTC will be cleared. |
The following conditions may cause the fault:
• | Side impact sensor circuit is open |
• | Side impact sensor is short to voltage or to ground. |
• | Side impact sensor has high or low resistance. |
• | The side impact sensor installed in the vehicle is not correct |
• | Side impact sensor internal fault |
Thoroughly inspect the wiring and connectors. Failure to do so may result in error of diagnosis and the trouble may occur again even when you replace the parts. If there is intermittent conditions, refer to Testing for Intermittent Conditions and Poor Connections .
The following numbers are corresponding to the steps in the diagnostic table.
This step tests if the side impact sensor signal circuit and voltage circuit is open or has high resistance.
This step tests the continuity of the side impact sensor signal circuit and voltage circuit.
This step tests if the side impact sensor signal circuit and voltage circuit is short to voltage.
Step | Action | Yes | No |
---|---|---|---|
Schematic for Reference: SIR Schematics Connector End View Reference: SIR Connector End Views | |||
1 | Have you conducted Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Important: J-45289 CANdi Module must be used together with the scan tool.
Does the scan tool indicate DTC B0085 as current trouble code? | Go to Step 3 | Go to Step 13 |
3 |
Is there damage or corrosion in the connectors? | Go to Step 4 | Go to Step 5 |
4 |
Is the trouble corrected? | Go to Step 11 | -- |
5 |
Is there damage or corrosion in the connectors? | Go to Step 6 | Go to Step 7 |
6 |
Is the trouble corrected? | Go to Step 11 | -- |
Do you find and correct the condition? | Go to Step 11 | Go to Step 8 | |
Test the continuity between the SDM connector side impact sensor signal circuit and voltage circuit. Refer to Circuit Testing . Do you find and correct the condition? | Go to Step 11 | Go to Step 9 | |
Do you find and correct the condition? | Go to Step 11 | Go to Step 10 | |
10 |
Have you finished the replacement? | Go to Step 11 | -- |
11 |
Does the DTC set again? | Go to Step 12 | System OK |
12 |
Have you finished the replacement? | Go to Step 13 | -- |
13 |
Does the DTC set again? | Go to Step 2 | System OK |