Pinpoint Test - DTC: R. Diagnosis and Testing

B1407:11, B1407:12, B1407:13 and B1407:1A

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

Normal Operation and Fault Symptoms

The RCM continuously monitors the passenger side airbag circuits for the following faults:

• Resistance Out of Range
• Unexpected Voltage
• Short to Ground
• Faulty passenger side airbag

When a fault is detected, the RCM stores DTC B1407:11, B1407:12, B1407:13 or B1407:1A in memory and sends a message to the IPC to turn on the airbag indicator.

The RCM analyzes the deployment loop resistance to determine if a fault 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 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 terminal connections. Crimps and terminals may be affected by seat belt stress and movement and may cause an increase in resistance due to wire tension. These variables can result in an intermittent fault. For this reason, the test requires the PID value to be within the desired range before the fault 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 repeat concerns. This test uses a process of elimination to diagnose each part of the deployment loop circuit, including:

• Wiring
• Connections
• Passenger Side Airbag
• RCM

DTC Fault Trigger Conditions

Possible Causes

• Wiring, Terminals or Connectors
• Passenger Side Airbag
• RCM

Visual Inspection and Preliminary Diagnosis

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