B0021

DTC B0021

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B0021 01
- Right Front Side Deployment Loop Short to Battery

DTC B0021 02
- Right Front Side Deployment Loop Short to Ground

DTC B0021 04
- Right Front Side Deployment Loop Open Circuit

DTC B0021 0D
- Right Front Side Deployment Loop Resistance Above Threshold

DTC B0021 0E
- Right Front Side Deployment Loop Resistance Below Threshold

Diagnostic Fault Information






Circuit/System Description

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.

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

B0021 01

The RF side impact module high and/or low circuit is short to voltage for 120 milliseconds.

B0021 02

The RF side impact module high and/or low circuit is short to ground for 120 milliseconds.

B0021 04

The RF side impact module high and/or low circuit is open for 120 milliseconds.

B0021 0D

The RF side impact module deployment loop resistance is greater than 3.9 ohms for 120 milliseconds.

B0021 0E

The RF side impact module deployment loop resistance is less than 1.1 ohms for 120 milliseconds.

Action Taken When the DTC Sets

* The SDM commands the AIR BAG indicator ON.
* The SDM will store a DTC, however if an event occurs system will still attempt deployments.

Conditions for Clearing the DTC

* The DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 50 ignition cycles.

Special Tools

* J 38715-A Driver and Passenger SIR Load Tool
* J-38715-30A SIR Load Tool Adapter

Circuit/System Testing

Important: Refer to SIR Service Precautions.

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 front end sensor.

* The SDM module

* The front end sensor wiring harness connector.

* The SDM wiring harness connector.

1. Ignition OFF, disconnect the harness connector at the RF inflatable restraint side impact module.
2. With the J-38715-30A SIR load tool adapter, connect J 38715-A in place of the RF inflatable restraint side impact module.
3. Ignition ON, with a scan tool, verify the appropriate DTC is set as current.

• If DTC is not set or is set as history, replace the RF inflatable restraint side impact module.

4. Ignition OFF, disconnect J 38715-A and the J-38715-30A SIR load tool adapter.
5. Disconnect the harness connector at the SDM.
6. Ignition ON, test for less than 1 volt between the RF inflatable restraint side impact module low control circuit terminal A and ground.

• If not within the specified range, test the circuit for a short to voltage.

7. Ignition OFF, test for infinite resistance between the RF inflatable restraint side impact module high control circuit terminal B and ground.

• If not within the specified range, test the circuit for a short to ground.

8. Test for less then 1 ohm between the RF inflatable restraint side impact module high control circuit terminal B and the SDM terminal 21.

• If not within the specified range, test the circuit for an open/high resistance.

9. Test for less then 1 ohm between the RF inflatable restraint side impact module low control circuit terminal A and the SDM terminal 20.

• If not within the specified range, test the circuit for an open/high resistance

10. If all circuits test normal, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Driver and Passenger Seat Side Inflatable Restraint Module Replacement
* Inflatable Restraint Side Impact Module Wiring Harness Replacement
* SIR/SRS Wiring Repairs