Pinpoint Test - DTC: C. Diagnosis and Verification

B0004:11, B0004:12, B0004:13 and B0004:1A

For circuit and connector information, refer to Wiring Diagrams Cell 46.

Normal Operation and Fault Symptoms

The RCM continuously monitors the driver lower airbag circuits for the following faults:

• Resistance Out of Range
• Unexpected Voltage
• Short to Ground
• Driver Lower Airbag Fault

When a fault is detected, the RCM stores DTC B0004:11, B0004:12, B0004:13 or B0004:1A in memory and sends a message to the IPC to illuminate the airbag indicator.

The RCM analyzes the deployment loop resistance to determine if a malfunction is present. The value displayed in the PID is the deployment loop resistance measured by the RCM. If the displayed value is below or above the desired range (see the chart below), the RCM may set a DTC. As the deployment loop resistance drifts further outside the desired range, the likelihood of a DTC setting increases. Small resistance fluctuations may occur due to the effect of road vibrations on the final seat belt connection. Crimps and terminals may be affected by stress and movement of the seat belt and may cause an increase in resistance due to wire tension. These variables may result in an intermittent fault. For this reason, the test requires the PID value to be within the desired range before the malfunction is considered repaired, regardless of whether the module reports the DTC on demand at the time of diagnosis. Following this direction helps ensure that minor resistance changes do not cause repeated concern. This test uses a process of elimination to diagnose each part of the deployment loop circuit, including:

• Wiring
• Connections
• Driver Knee Airbag
• RCM

DTC Fault Trigger Conditions

Possible Causes

• Wiring, Terminals or Connectors
• Driver Knee Airbag
• RCM

Visual Inspection and Preliminary Diagnosis

• Inspect the wiring harness for damage.
• Inspect the connectors for loose or damaged terminals.