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Home >> Jeep >> 2006 >> Commander Base, 4.7 N, 4WD >> Repair and Diagnosis >> Restraints >> Restraints Control Systems >> DTCS B1BBC To B2210 >> Diagnosis And Testing >> B2101-Ignition Run/Start Input Circuit Low >> Diagnostic Test
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Diagnostic Test

  1. 1) VERIFY THAT DTC B2101-IGNITION RUN/START INPUT CIRCUIT LOW IS ACTIVE IN THE ORC. 
    NOTE: Ensure the battery is fully charged.

    Turn the ignition on.

    With the scan tool, read Occupant Restraint Controller (ORC) DTCs.

    Does the scan tool display active: B2101-IGNITION RUN/START INPUT CIRCUIT LOW? 

    Yes 

    1. Go To  3).

    No 

    1. Go To  2).
  2. 2) CHECK FOR ACTIVE DTC B2101-IGNITION RUN/START INPUT CIRCUIT LOW IN OCM. 

    With the scan tool, read Occupant Classification Module (OCM) DTCs.

    Does the scan tool display active: B2101-IGNITION RUN/START INPUT CIRCUIT LOW? 

    Yes 

    1. Go To  6).

    No 

    1. Go To  11).
  3. 3) INSPECT AIRBAG RUN-START FUSE (IPM 29) 

    Turn the ignition off.

    Remove the Airbag Run-Start Fuse 29 from the IPM and inspect the fuse.

    NOTE: Check connectors - Clean and repair as necessary.

    Is the Run/Start fuse open? 

    Yes 

    1. Go To  4).

    No 

    1. Go To  8).
  4. 4) CHECK (F20) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT RESISTANCE 
    Fig 1: Checking Fused Ignition Switch Output (RUN-START) Circuit
    GC0027692Courtesy of DAIMLERCHRYSLER CORP.

    Measure the resistance of the (F20) Fused Ignition Switch Output (Run-Start) circuit between ground and the Airbag Run-Start fuse terminal (output side).

    Is the resistance below 100.0 ohms? 

    Yes 

    1. Go To  5).

    No 

    1. Using the wiring diagram/schematic as a guide, inspect the related wiring and connectors. Look for chafed, pierced, pinched, or partially broken wires and broken, bent, pushed out, spread, corroded, or contaminated terminals.
    2. Replace Airbag Run-Start Fuse.
    3. Perform *ORC VERIFICATION TEST - VER 1 .
  5. 5) CHECK (F20) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT RESISTANCE WITH ORC CONNECTORS DISCONNECTED 
    Fig 2: Checking Fused Ignition Switch Output (RUN-START) Circuit
    GC0027693Courtesy of DAIMLERCHRYSLER CORP.
    WARNING: If the Occupant Restraint Controller is dropped at any time, it must be replaced. Failure to take the proper precautions can result in accidental airbag deployment and personal injury or death.
    WARNING: To avoid personal injury or death, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

    Disconnect the both ORC connectors.

    NOTE: Check connectors - Clean and repair as necessary.

    Connect the Load Tool ORC 8443-24 Adaptor to the ORC C2 connector.

    Measure the resistance of the (F20) Fused Ignition Switch Output (Run-Start) circuit between 8443-24 adaptor and ground).

    Is the resistance below 100.0 ohms? 

    Yes 

    1. Repair the (F20) Fused Ignition Switch Output (Run-Start) circuit for a short to ground.
    2. Replace the Airbag Run-Start Fuse.
    3. Perform *ORC VERIFICATION TEST - VER 1 .

    No 

    1. Replace the ORC in accordance with the Service Information.
    2. Replace the Airbag Run-Start Fuse.
    3. Perform *ORC VERIFICATION TEST - VER 1 .
  6. 6) INSPECT AIRBAG RUN-START FUSE (JB 19) 
    Fig 3: Checking JB Fuse No. 19
    GC0027694Courtesy of DAIMLERCHRYSLER CORP.

    Turn the ignition off.

    Remove the Airbag Run-Start Fuse 19 from the Junction Block and inspect the fuse.

    NOTE: Check connectors - Clean and repair as necessary.

    Is the Run/Start fuse open? 

    Yes 

    1. Go To  7).

    No 

    1. Go To  10).
  7. 7) CHECK (F200) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT RESISTANCE WITH OCM C1 CONNECTOR DISCONNECTED 
    Fig 4: Checking Fused Ignition Switch Output (RUN-START) Circuit
    GC0027695Courtesy of DAIMLERCHRYSLER CORP.
    WARNING: If the Occupant Classification Module is dropped at any time, it must be replaced. Failure to take the proper precautions can result in accidental airbag deployment and personal injury or death.

    Disconnect the OCM C1 connector.

    Measure the resistance of the (F200) Fused Ignition Switch Output (Run-Start) circuit between ground and the Occupant Classification Module C1 connector.

    Is the resistance below 100.0 ohms? 

    Yes 

    1. Repair the (F200) Fused Ignition Switch Output (Run-Start) circuit for a short to ground.
    2. Replace the Airbag Run-Start Fuse.
    3. Perform *OCS VERIFICATION TEST - VER 1 .

    No 

    1. Replace the OCM in accordance with the Service Information.
    2. Replace the Airbag Run-Start Fuse.
    3. Perform *OCS VERIFICATION TEST - VER 1 .
  8. 8) CHECK (F944) IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT FOR AN OPEN 
    Fig 5: Checking Ignition Switch Output (RUN-START) Circuit
    GC0027696Courtesy of DAIMLERCHRYSLER CORP.

    Turn the ignition on.

    Measure the voltage of the (F944) Ignition Switch Output (Run-Start) circuit at the Airbag Run-Start fuse terminal (supply side).

    Is the voltage above 6.0 volts? 

    Yes 

    1. Go To  9).

    No 

    1. Repair the open (F944) Ignition Switch Output (Run-Start) circuit.
    2. Perform *ORC VERIFICATION TEST - VER 1 .
  9. 9) CHECK (F20) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT FOR AN OPEN 
    Fig 6: Checking Fused Ignition Switch Output (RUN-START) Circuit
    GC0027697Courtesy of DAIMLERCHRYSLER CORP.
    WARNING: To avoid personal injury or death, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

    Reinstall the Airbag Run-Start Fuse.

    Disconnect the both ORC connectors.

    NOTE: Check connectors - Clean and repair as necessary.

    Install the Airbag Load tool ORC 8443-24 adaptor to the ORC C2 connector.

    WARNING: To avoid personal injury or death, turn the ignition on, then reconnect the battery.

    Measure the voltage of the (F20) Fused Ignition Switch Output (Run-Start) Circuit between the 8443-24 connector and ground.

    Is the voltage above 6.0 volts? 

    Yes 

    1. Replace the ORC in accordance with the Service Information.
    2. Perform *ORC VERIFICATION TEST - VER 1 .

    No 

    1. Repair the open (F20) Fused Ignition Switch Output (Run-Start) circuit.
    2. Perform *ORC VERIFICATION TEST - VER 1 .
  10. 10) CHECK (F200) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT FOR AN OPEN 
    Fig 7: Checking Fused Ignition Switch Output (RUN-START) Circuit
    GC0027698Courtesy of DAIMLERCHRYSLER CORP.
    WARNING: To avoid personal injury or death, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

    Reinstall the JB 19 Airbag Run-Start Fuse.

    Disconnect both Occupant Classification Module (OCM) connectors.

    NOTE: Check connectors - Clean and repair as necessary.
    WARNING: To avoid personal injury or death, turn the ignition on, then reconnect the battery.

    Measure the voltage of the (F200) Fused Ignition Switch Output (Run-Start) Circuit between the OCM connector and ground.

    Is the voltage above 6.0 volts? 

    Yes 

    1. Replace the Occupant Classification Module (OCM) in accordance with the Service Information.
    2. Perform *OCS VERIFICATION TEST - VER 1 .

    No 

    1. Repair the open (F200) Fused Ignition Switch Output (Run-Start) circuit between the OCM and the splice.
    2. Perform *OCS VERIFICATION TEST - VER 1 .
  11. 11) TEST FOR INTERMITTENT CONDITION 

    With the scan tool, record and erase all DTCs from all Airbag modules.

    If any ACTIVE codes are present they must be resolved before diagnosing any stored codes.

    WARNING: To avoid personal injury or death, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

    Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.

    Look for chafed, pierced, pinched, or partially broken wires and broken, bent, pushed out, spread, corroded, or contaminated terminals.

    The following additional checks may assist you in identifying a possible intermittent problem.

    Reconnect any disconnected components and harness connector.

    WARNING: To avoid personal injury or death, turn the ignition on, then reconnect the battery.

    With the scan tool, monitor active codes as you work through the following steps.

    WARNING: To avoid personal injury or death, maintain a safe distance from all airbags while performing the following steps.

    Wiggle the wiring harness and connectors of the related airbag circuit or component.

    If codes are related to the Driver Airbag circuits, rotate the steering wheel from stop to stop.

    If only stored codes return, continue the test until the problem area has been isolated.

    In the previous steps you have attempted to recreate the conditions responsible for setting the active DTC in question.

    Does the scan tool display any ACTIVE DTCs? 

    Yes 

    1. Select appropriate symptom from DIAGNOSTIC CODE INDEX .

    No  

    1. No problem found at this time. Perform *OCS VERIFICATION TEST - VER 1 . Erase all codes before returning vehicle to customer.
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