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Diagnostic Test

  1. 1) DTC IS ACTIVE 

    Turn the ignition on.

    With the scan tool, monitor the Brake Signal 1 and Brake Signal 2 states while pressing and releasing the brake pedal several times.

    Do the Brake Signal states change appropriately as the pedal is pressed and released? 

    Yes 

    1. Refer to *CHECKING FOR AN INTERMITTENT DTC .

    No 

    1. Go to  2).
  2. 2) (B29) BRAKE SIGNAL 1 CIRCUIT 
    Fig 1: Checking The Brake Signal 1 Circuit At The Appropriate Terminal Of Special Tool #8815 While Pressing And Releasing The Brake Pedal Several Times Using A 12 Volt Test Light Connected To 12 Volts
    GC0061115Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the Powertrain Control Module (PCM) connector.

    CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

    Using a 12 volt test light connected to 12 volts, check the (B29) Brake Signal 1 circuit at the appropriate terminal of special tool #8815 while pressing and releasing the brake pedal several times.

    Does the test light change from illuminated to not illuminated as the brake pedal is pressed and released? 

    Yes 

    1. Go to  3).

    No 

    1. Go to  4).
  3. 3) (B16) BRAKE SIGNAL 2 CIRCUIT 
    Fig 2: Checking The Brake Signal 2 Circuit At The Appropriate Terminal Of Special Tool #8815 While Pressing And Releasing The Brake Pedal Several Times Using A 12 Volt Test Light Connected To Ground
    GC0061116Courtesy of CHRYSLER LLC

    Turn the ignition on.

    CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

    Using a 12 volt test light connected to ground, check the (B16) Brake Signal 2 circuit at the appropriate terminal of special tool #8815 while pressing and releasing the brake pedal several times.

    Does the test light change from illuminated to not illuminated as the brake pedal is pressed and released? 

    Yes 

    1. Go to  11).

    No 

    1. Go to  7).
  4. 4) (Z429) GROUND CIRCUIT OPEN OR HIGH RESISTANCE 
    Fig 3: Checking The Ground Circuit In The Stop Lamp Switch Harness Connector Using A 12 Volt Test Light Connected To 12 Volts
    GC0049624Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the Stop Lamp Switch connector.

    Using a 12 volt test light connected to 12 volts, check the (Z429) Ground circuit in the Stop Lamp Switch harness connector.

    NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

    Is the test light illuminated and bright? 

    Yes 

    1. Go to  5).

    No 

    1. Repair the (Z429) Ground circuit for an open circuit or high resistance.
    2. Perform PCM VERIFICATION TEST .
  5. 5) (B29) BRAKE SIGNAL 1 CIRCUIT SHORTED TO GROUND 
    Fig 4: Measuring The Resistance Between Ground And The Brake Signal 1 Circuit In The Stop Lamp Switch Harness Connector
    GC0049625Courtesy of CHRYSLER LLC

    Measure the resistance between ground and the (B29) Brake Signal 1 circuit in the Stop Lamp Switch harness connector.

    Is the resistance above 100 ohms? 

    Yes 

    1. Go to  6).

    No 

    1. Repair the (B29) Brake Signal 1 circuit for a short to ground.
    2. Perform PCM VERIFICATION TEST .
  6. 6) (B29) BRAKE SIGNAL 1 CIRCUIT OPEN OR HIGH RESISTANCE 
    Fig 5: Measuring The Resistance Of The Brake Signal 1 Circuit Between The Stop Lamp Switch Harness Connector And The Appropriate Terminal Of Special Tool #8815
    GC0049626Courtesy of CHRYSLER LLC
    CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

    Measure the resistance of the (B29) Brake Signal 1 circuit between the Stop Lamp Switch harness connector and the appropriate terminal of special tool #8815.

    Is the resistance below 5.0 ohms? 

    Yes 

    1. Go to  10).

    No 

    1. Repair the (B29) Brake Signal 1 circuit for an open circuit or high resistance.
    2. Perform PCM VERIFICATION TEST .
  7. 7) (F20) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT OPEN OR HIGH RESISTANCE 
    Fig 6: Checking The Fused Ignition Switch Output Circuit In The Stop Lamp Switch Harness Connector Using A 12 Volt Test Light Connected To Ground
    GC0049627Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the Stop Lamp Switch connector.

    Turn the ignition on.

    Using a 12 volt test light connected to ground, check the (F20) Fused Ignition Switch Output (Run-Start) circuit in the Stop Lamp Switch harness connector.

    NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

    Is the test light illuminated and bright? 

    Yes 

    1. Go to  8).

    No 

    1. Repair the (F20) Fused Ignition Switch Output (Run-Start) circuit for an open circuit or high resistance.
    2. Perform PCM VERIFICATION TEST .
  8. 8) (B16) BRAKE SIGNAL 2 CIRCUIT SHORTED TO VOLTAGE 
    Fig 7: Measuring The Voltage Of The Brake Signal 2 Circuit In The Stop Lamp Switch Harness Connector
    GC0049628Courtesy of CHRYSLER LLC

    Measure the voltage of the (B16) Brake Signal 2 circuit in the Stop Lamp Switch harness connector.

    Is there any voltage present? 

    Yes 

    1. Repair the (B16) Brake Signal 2 circuit for a short to voltage.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Go to  9).
  9. 9) (B16) BRAKE SIGNAL 2 CIRCUIT OPEN OR HIGH RESISTANCE 
    Fig 8: Measuring The Resistance Of The Brake Signal 2 Circuit Between The Stop Lamp Switch Harness Connector And The Appropriate Terminal Of Special Tool #8815
    GC0049629Courtesy of CHRYSLER LLC

    Turn the ignition off.

    CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

    Measure the resistance of the (B16) Brake Signal 2 circuit between the Stop Lamp Switch harness connector and the appropriate terminal of special tool #8815.

    Is the resistance below 5.0 ohms? 

    Yes 

    1. Go to  10).

    No 

    1. Repair the (B16) Brake Signal 2 circuit for an open circuit or high resistance.
    2. Perform PCM VERIFICATION TEST .
  10. 10) STOP LAMP SWITCH 

    Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Stop Lamp Switch and the Powertrain Control Module (PCM).

    Look for any chafed, pierced, pinched, or partially broken wires.

    Look for broken, bent, pushed out or corroded terminals.

    Refer to any Technical Service Bulletins that may apply.

    Were any problems found? 

    Yes 

    1. Repair as necessary.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Replace the Stop Lamp Switch in accordance with the Service Information.
    2. Perform PCM VERIFICATION TEST .
  11. 11) POWERTRAIN CONTROL MODULE (PCM) 

    Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Stop Lamp Switch and the Powertrain Control Module (PCM).

    Look for any chafed, pierced, pinched, or partially broken wires.

    Look for broken, bent, pushed out or corroded terminals.

    Refer to any Technical Service Bulletins that may apply.

    Were any problems found? 

    Yes 

    1. Repair as necessary.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
    2. Perform PCM VERIFICATION TEST .
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