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Pinpoint Test Z: No Communication With The Restraints Control Module (RCM)

WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION: When installing a new restraints control module (RCM), always make sure the correct RCM is being installed. The RCM 40-pin connector is keyed differently for vehicles with safety canopies and side air bags than the 40-pin connector for vehicles without safety canopies and side air bags. Do not force the 40-pin connector onto the RCM. If the connector is forced onto the RCM, damage to the RCM and/or connector will occur.
NOTE: Most faults are due to connector and/or wiring concerns. Carry out a thorough Inspection and Verification  before proceeding with the Pinpoint Test.
  1. Z1 CHECK THE RCM C2041a PIN 11 FOR DAMAGE 
    WARNING:
    1. Restraint system diagnostic tools are for service only. Tools must be removed prior to operating the vehicle over the road. Failure to remove restraint system diagnostic tools could result in injury and possible violation of vehicle safety standards.
    2. Do not handle, move or change the original horizontal mounting position of the restraints control module (RCM) while the RCM is connected and the ignition switch is ON. Failure to follow these instructions may result in the inadvertent deployment of the safety canopy and risk of personal injury.
    3. Never probe the connectors on the air bag module. Doing so can result in air bag deployment, which can result in personal injury.
    4. The safety belt pretensioner is a pyrotechnic device. Always wear safety glasses when repairing an air bag equipped vehicle and when handling a safety belt buckle pretensioner or safety belt retractor pretensioner. Never probe a pretensioner electrical connector. Doing so could result in pretensioner or air bag deployment and could result in personal injury.
    5. Never probe the electrical connector on a safety canopy module. Doing so can result in safety canopy deployment.
    NOTE:
    1. If a seat equipped with a supplemental restraint system (SRS) component is being serviced, the SRS must be depowered.
    2. After diagnosing or repairing an SRS, the restraint system diagnostic tools must be removed before operating the vehicle over the road  .
    3. The SRS must be fully operational and free of faults before releasing the vehicle to the customer.

    Yes:  GO to  Z2.

    No:  REPAIR RCM C2041a or RCM C2041a pin 11 as necessary. RETEST the communication to the RCM. RECONNECT the system. If previously directed to deactivate the system, REACTIVATE the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION . REPOWER the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING . PROVE OUT the system. CLEAR all DTCs.

  2. Z2 CHECK DLC C251 PIN 7 FOR DAMAGE 
    • Inspect DLC C251 and DLC C251 pin 7 for damage.
      Fig 1: Locating DLC C251 Pin 7 For Damage
      G04622724Courtesy of FORD MOTOR CO.
    • Are DLC C251 and DLC C251 pin 7 OK? 

    Yes:  GO to  Z3.

    No:  REPAIR DLC C251 or DLC C251 pin 7 as necessary. RETEST the communication to the RCM. RECONNECT the system. If previously directed to deactivate the system, REACTIVATE the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION . REPOWER the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING . PROVE OUT the system. CLEAR all DTCs.

  3. Z3 CHECK THE IGNITION CIRCUIT 937 (RD/WH) FOR AN OPEN 
    • Key in OFF position.
    • Deactivate the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION .
    • Key in ON position.
    • Measure the voltage between RCM C2041a-12, circuit 937 (RD/WH), harness side and ground.
      Fig 2: Checking Ignition Circuit 937 (RD/WH) For Open
      G04622725Courtesy of FORD MOTOR CO.
    • Is the voltage greater than 10 volts? 

    Yes:  GO to  Z4.

    No:  VERIFY smart junction box (SJB) fuse 33 (15A) is OK. If OK, REPAIR circuit 937 (RD/WH). RETEST the communication to the RCM. RECONNECT the system. If previously directed to deactivate the system, REACTIVATE the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION . REPOWER the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING . PROVE OUT the system. CLEAR all DTCs.

  4. Z4 CHECK GROUND CIRCUIT 1203 (BK/LB) FOR AN OPEN 
    • Key in OFF position.
    • Measure the resistance between RCM C2041a-16, circuit 1203 (BK/LB), harness side and a sheet metal ground near the RCM.
      Fig 3: Checking Ground Circuit 1203 (BK/LB) For Open
      G04622726Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 

    Yes:  GO to  Z5.

    No:  REPAIR circuit 1203 (BK/LB). RETEST the communication to the RCM. RECONNECT the system. If previously directed to deactivate the system, REACTIVATE the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION . REPOWER the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING . PROVE OUT the system. CLEAR all DTCs.

  5. Z5 CHECK CIRCUIT 70 (LB/WH) FOR AN OPEN 
    • Measure the resistance between RCM C2041a-11, circuit 70 (LB/WH), harness side and DLC C251-7, circuit 70 (LB/WH), harness side.
      Fig 4: Checking Circuit 70 (LB/WH) For Open
      G04622727Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 

    Yes:  GO to  Z6.

    No:  REPAIR circuit 70 (LB/WH). RETEST the communication to the RCM. RECONNECT the system. If previously directed to deactivate the system, REACTIVATE the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION . REPOWER the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING . PROVE OUT the system. CLEAR all DTCs.

  6. Z6 CONFIRM THE RCM FAULT 
    NOTE: Make sure the safety belt pretensioner restraint system diagnostic tools, sensor electrical connector and the RCM electrical connector are connected before carrying out the on-demand self test. If not, erroneous DTCs will be recorded.
    • Key in OFF position.
    • Connect: RCM C2041a and C2041b.
    • Enter the following diagnostic mode on the scan tool: On-Demand Self Test.
    • Did the diagnostic tool communicate with the RCM? 

    Yes:  Fault corrected. RECONNECT the system. If previously directed to deactivate the system, REACTIVATE the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION . REPOWER the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING . PROVE OUT the system. CLEAR all DTCs.

    No:  INSTALL a new RCM. REFER to RESTRAINTS CONTROL MODULE (RCM) . RETEST the communication to the RCM. RECONNECT the system. If previously directed to deactivate the system, REACTIVATE the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION . REPOWER the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING . PROVE OUT the system. CLEAR all DTCs.

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