Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
Side Impact Module - RF High Circuit | B0021 02 | B0021 0D | B0021 04 | B0021 01 | B0021 0E |
Side Impact Module - RF Low Circuit | B0021 02 | B0021 0D | B0021 04 | B0021 01 | B0021 0E |
During a side or frontal crash of sufficient force, the inflatable restraint sensing and diagnostic module (SDM) will allow current to flow through the deployment loop in order to deploy the side impact module - RF. The SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage.
A shorting bar used within the side impact module - RF connector which will short together both side impact module - RF high and low circuits when the connector is disconnected. This will help to prevent unwanted deployment of the inflator module during servicing.
Ignition voltage is between 9-16 volts.
The side impact module - RF high and/or low circuit is short to voltage for 120 milliseconds.
The side impact module - RF high and/or low circuit is short to ground for 120 milliseconds.
The side impact module - RF high and/or low circuit is open for 120 milliseconds.
The side impact module - RF deployment loop resistance is more than 3.9 ohms for 120 milliseconds.
The side impact module - RF deployment loop resistance is less than 1.1 ohms for 120 milliseconds.
• | The SDM commands the AIR BAG indicator ON via serial data communications. |
• | The SIR system is disabled and no deployments are allowed. |
• | The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used. |
• | A history DTC will clear once 255 malfunction-free ignition cycles have occurred. |
• | J 38715-A SIR Driver/Passenger Load Tool |
• | EL 38715-150 SIR Load Tool Adapter |
• | J 38715-30A SIR Load Tool Adapter |
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 side impact module - RF • The side impact module wiring harness • The SDM module • The side impact module - RF wiring harness connector • The side impact module wiring harness connector • The SDM wiring harness connector
⇒ | If DTC B0021 is current, turn OFF the ignition and remove the SDM connector. Refer to SDM replacement in Repair Instructions for connector location. |
⇒ | Test and repair both side impact module - RF high and low circuits for a short to voltage, short to ground, or open/low resistance. If all circuits test normal, replace the SDM. |
⇒ | If DTC B0021 is current, replace the side impact module - RF wiring harness. |
Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for SDM replacement, setup, and programming |