Diagnostic Instructions
DTC Descriptors
DTC B1635: Left Rear Side Impact Sensor (SIS) Performance
Circuit/System Description
The inflatable restraint front end sensor utilizes a bidirectional 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 for 2 seconds:
B1635
| • | The side impact sensor circuit is shorted. |
| • | The side impact sensor circuit is open. |
| • | Left front side impact sensor malfunction. |
| • | Left rear side impact sensor malfunction. |
Action Taken When the DTC Sets
| • | The SDM commands the AIR BAG indicator ON. |
| • | 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
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.
Circuit/System Testing
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:
| • | The front end sensor wiring harness connector |
| • | The SDM wiring harness connector |
- Ignition OFF, disconnect the harness connector at the right rear side impact sensor and the right front side impact sensor.
- Ignition ON, test for less than 1 volt between the signal circuit terminal 1 and ground.
| ⇒ | If greater than the specified range, repair the circuit for a short to voltage. |
- Ignition ON, test for less than 1 volt between the low reference circuit terminal 2 and ground.
| ⇒ | If greater than the specified range, repair the circuit for a short to voltage. |
- Test for infinite resistance between the signal circuit terminal 1 and ground.
| ⇒ | If less than infinite resistance, repair the circuit for a short to ground. |
- Test for less than 1 ohm between left front side impact sensor terminal 1 and left rear side impact sensor connector terminal 2.
| ⇒ | If greater than the specified range, repair the circuit for an open/high resistance. |
- Test for less then 1 ohm between left front side impact sensor terminal 2 and left rear side impact sensor connector terminal 1.
| ⇒ | If greater than the specified range, repair the circuit for an open/high resistance. |
- If all circuits test normal, replace the rear sensor.
- Rconnect all SIR components. Ignition ON, with a scan tool clear and check for DTC B1635.
| ⇒ | If the DTC returns and is current, replace the front side impact sensor. |
- Reconnect all SIR components. Ignition ON, with a scan tool clear and check for DTC B1635.
| ⇒ | If the DTC returns and is current, replace the SDM. |
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
