Pinpoint Test RA: Left Air Curtain (Inline): Notes

Refer to appropriate Supplemental Restraint System in OEM Wiring Diagrams article, for schematic and connector information.

Normal Operation and Fault Conditions 

The RCM continuously monitors the left air curtain circuits for the following faults:

• Resistance out of range
• Unexpected voltage
• Short to ground
• Faulted left air curtain

If a fault is detected, the RCM stores DTC B0021:11, B0021:12, B0021:13, B0021:1A, B1405:11, B1405:12, B1405:13 or B1405:1A in memory and sends a message to the IPC to illuminate the airbag warning indicator.

The RCM analyzes the deployment loop resistance to determine if a fault exists. The value displayed in the PID is the deployment loop resistance measured by the RCM. If the value displayed is lower or higher than the desired range (refer to diagram below in illustration), the RCM can set a DTC. As the deployment loop resistance drifts farther outside the desired range, the chance for a DTC increases. Small variations in resistance can occur due to the effect of road vibrations on terminal fit. Crimps and terminals can be affected by stress and harness movement and can cause an increase in resistance due to wire strain. 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 if the module is reporting an on-demand DTC at the time of diagnosis. Following this direction helps make sure that minor changes in resistance do not create a repeat concern. This test uses process of elimination to diagnose each part of the deployment loop circuit including:

• Wiring
• Connections
• Left air curtain

PPT R RCM DTC FAULT TRIGGER CONDITIONS 

DTC	Description	Fault Trigger Conditions
B0021:11	Left Curtain Deployment Control 1: Circuit Short to Ground	Sets when the RCM senses a short to ground on either left hand side air curtain circuit for more than 6 seconds.
B0021:12	Left Curtain Deployment Control 1: Circuit Short to Battery	Sets when the RCM senses a short to voltage on either left hand side air curtain circuit for more than 6 seconds.
B0021:13	Left Curtain Deployment Control 1: Circuit Open	Sets when the RCM measures more than the desired resistance range between the left hand side air curtain circuits for more than 6 seconds.
B0021:1A	Left Curtain Deployment Control 1: Circuit Resistance Below Threshold	Sets when the RCM measures less than the desired resistance range between the left hand side air curtain circuits for more than 6 seconds.

Possible Causes 

• Wiring, terminals or connectors
• Left air curtain
• RCM