Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using the diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC B1620 : Electronic Control Unit PerformanceCircuit/System Description
When the ignition switch is turned to ON, the sensing and diagnostic module (SDM) will perform turn-on test to diag-nose critical malfunctions within SDM itself.
Conditions for Running the DTC
Ignition voltage is between 9-16 volts.
Conditions for Setting the DTC
The SDM does not implement diagnostic operation. In case of above, the wiring harness of SDM should be checked before replacing the SDM.
Action Taken When the DTC Sets
| • | The SDM commands ON the AIR BAG warning lamp via serial data communications. |
| • | The SDM disables all deployments. |
Conditions for Clearing the DTC
The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
Reference Information
Electrical Information Reference
Circuit/System Testing
- Ignition ON, use the scan tool to request SIR DTCs. Verify that DTC B1620 is set as current.
- Ignition ON, use the scan tool to clear the DTCs.
Important: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.
• The I/P module • The SDM module • The I/P wiring harness connector • The SDM wiring harness connector
| ⇒ | If DTC B1620 was 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
