B0072 MERCURY - Passenger Seatbelt Pretensioner 'A' Deployment Control
B0072 Mercury Possible Causes
- Faulty Passenger Seatbelt Pretensioner
- Passenger Seatbelt Pretensioner harness is open or shorted
- Passenger Seatbelt Pretensioner circuit poor electrical connection
- Faulty Restraints Control Module (RCM)
B0072 Mercury Tech NotesB0072:11 Passenger Seatbelt Pretensioner 'A' Deployment Control: Circuit Short to Ground
B0072:12 Passenger Seatbelt Pretensioner 'A' Deployment Control: Circuit Short to Battery
B0072:13 Passenger Seatbelt Pretensioner 'A' Deployment Control: Circuit Open
B0072:1A Passenger Seatbelt Pretensioner 'A' Deployment Control: Circuit Resistance Below Threshold
B0072 Mercury Possible Symptoms
- Air Bag Warning Light ON
B0072 Mercury MeaningThe Restraints Control Module (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, the RCM can set a Diagnostic Trouble Code (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 the process of elimination to diagnose each part of the deployment loop circuit including:
- Driver seatbelt anchor pretensioner
Precautions for SRS “AIR BAG” and “SEAT BELT PRE-TENSIONER” Service
- Never probe the electrical connectors on air bag, side air curtain modules or seat belts.
- Never disassemble or tamper with safety belt buckle/retractor pretensioners, adaptive load limiting retractors, safety belt inflators, or probe the electrical connectors.
- Do not use electrical test equipment to check SRS circuits unless instructed to in this Service Manual.
- Before servicing the SRS, turn ignition switch OFF, disconnect both battery cables and wait at least 3 minutes. For approximately 3 minutes after the cables are removed, it is still possible for the air bag and seat belt pre-tensioner to deploy. Therefore, do not work on any SRS connectors or wires until at least 3 minutes have passed.