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Home >> Mercury >> 2008 >> Milan Base, 3.0 1, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 628 (Supplemental Restraint System) >> Diagnosis And Testing >> Pinpoint Tests - Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS) >> Pinpoint Tests >> Pinpoint Test A: The Air Bag Indicator is Illuminated Continuously/No Communication With the Restraints Control Module (RCM) >> Pinpoint Test A: The Air Bag Indicator Is Illuminated Continuously/No Communication With The Restraints Control Module (RCM)

Pinpoint Test A: The Air Bag Indicator Is Illuminated Continuously/No Communication With The Restraints Control Module (RCM)

WARNING: This page is about a different car, the 2006 Mercury Milan, 2006 Lincoln Zephyr, and 2006 Ford Fusion. 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 side air curtains and side air bags than the 40-pin connector for vehicles without side air curtains 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. A1 CHECK FOR CONTINUOUS OR ON-DEMAND SELF TEST DTCs 
    WARNING: 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.
    WARNING: Never probe the electrical connector on a side air curtain module. Doing so can result in side air curtain deployment.
    WARNING: 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.
    WARNING: Never probe the electrical connector on a side air curtain module. Doing so can result in side air curtain deployment.
    NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.
    • Enter the following diagnostic mode on the scan tool: On-Demand Self Test/Retrieve and Record Continuous Memory DTCs.
    • Enter the following diagnostic mode on the scan tool: View and Record DTC Fault PIDs.
    • Were any continuous or on-demand self test DTCs retrieved? 

    Yes  : If continuous DTCs were retrieved, GO to A2. If on-demand DTCs were retrieved, GO to the SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DIAGNOSTIC TROUBLE CODE (DTC) TABLE  for pinpoint test direction.

    No  : If the RCM does  communicate with the diagnostic tool, GO to A2.

    If the RCM does not  communicate with the diagnostic tool, GO to  A6.

  2. A2 CHECK HS-CAN NETWORK 
    • Enter the following diagnostic mode on the scan tool: Carry Out The Data Link Diagnostics.
    • Did the Data Link Diagnostics test pass? 

    Yes  : GO to A3.

    No  : REFER to MODULE COMMUNICATIONS NETWORK to diagnose the HS-CAN concern. GO to  A6.

  3. A3 CHECK INSTRUMENT CLUSTER MODULE 
    • Enter the following diagnostic mode on the scan tool: Instrument Cluster Module Active Command - Indicator Lamp Control 1.
    • Does the air bag warning indicator turn ON and OFF when using the active command? 

    Yes  : INSTALL and CONFIGURE a new RCM. REFER to RESTRAINTS CONTROL MODULE (RCM) . GO to  A6.

    No  : INSTALL a new instrument cluster module. REFER to INSTRUMENT CLUSTER . GO to  A6.

  4. A4 CHECK CIRCUIT CBP21 (BU/GY) FOR AN OPEN 
    • Deactivate the SRS. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION .
    • Disconnect: RCM C310a and C310b.
    • Measure the voltage between RCM C310a-24, circuit CBP21 (BU/GY), harness side and ground.
      Fig 1: Checking Circuit CBP21 (BU/GY) For Open
      G04683835Courtesy of FORD MOTOR CO.
    • Is the voltage between 8 and 18 volts? 

    Yes  : GO to A5.

    No  : Verify that the smart junction box (SJB) fuse 25 (7.5A) is OK. If OK, REPAIR circuit CBP21 (BU/GY). GO to  A6.

  5. A5 CHECK RCM CASE GROUND 
    • Key in OFF position.
    • Measure the resistance between the RCM case and a good chassis ground.
    • Is the resistance less than 5 ohms? 

    Yes  : REFER to MODULE COMMUNICATIONS NETWORK to diagnose the HS-CAN concern. GO to A6.

    No  : REPAIR RCM case ground as necessary. GO to A6.

  6. A6 CHECK FOR ADDITIONAL DTCs 
    • Refer to the continuous memory DTCs recorded during Step  A1.
    • Were any continuous memory DTCs retrieved during Step   A1 ? 

    Yes  : Do not clear any DTCs until all DTCs have been resolved. GO to the SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DIAGNOSTIC TROUBLE CODE (DTC) TABLE  for pinpoint test direction.

    No  : RECONNECT the system. RETEST the communication to the RCM. 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 OCS module and RCM DTCs.

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