LEMON Manuals: Even more car manuals for everyone
Home >> Jeep >> 2014 >> Wrangler Sahara, Standard Trans >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> 3.6L - DTCS P0461 To P0652 >> Diagnosis And Testing >> P0571-Brake Switch 1 Performance >> Diagnostic Test

Diagnostic Test

  1. CHECK THE BRAKE SWITCH 1 STATUS 
    1. Turn the ignition on.
    2. While observing the BRAKE SWITCH 1 status on the scan tool display, press and release the brake pedal several times.

      Does the scan tool display BRAKE SWITCH 1: PRESSED and NOT PRESSED for the appropriate pedal position?

      Yes 

      • Go To  2

      No 

      • Go To  8
  2. CHECK THE BRAKE SWITCH 2 STATUS 
    1. While observing the BRAKE SWITCH 2 status on the scan tool display, press and release the brake pedal several times.

      Does the scan tool display BRAKE SWITCH 2: PRESSED and NOT PRESSED for the appropriate pedal position?

      Yes 

      • Go To  3

      No 

      • Go To  4
  3. INTERMITTENT CONDITION 
    NOTE:

    The conditions that set the DTC are not present at this time. The following list may help in identifying the intermittent condition.

    1. With the engine running at normal operating temperature, monitor the scan tool parameters related to the DTC while wiggling the wiring harness. Look for parameter values to change and/or a DTC to set.
    2. Review the DTC When Monitored and Set Conditions. If possible, try to duplicate the conditions under which the DTC was set.
    3. Perform any Technical Service Bulletins (TSB) that may apply.
    4. Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.
    5. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.

      Were any of the above conditions present?

      Yes 

      No 

      • Test Complete.
  4. CHECK THE (F941) IGNITION SWITCH START/RUN CIRCUIT FOR AN OPEN 
    1. Turn the ignition off.
    2. Disconnect the Brake Lamp Switch harness connector.
    3. Turn the ignition on.
    4. Using a 12-volt test light connected to ground, probe the (F941) Ignition Switch Start/Run circuit at the Brake Lamp Switch harness connector.
      NOTE:

      The test light should be illuminated and bright.

      Is the test light illuminated and bright?

      Yes 

      • Go To  5

      No 

      • Repair the (F941) Ignition Switch Start/Run circuit for an open.
      • Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  5. CHECK THE (B16) BRAKE SWITCH 2 SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE 
    1. Measure the voltage on the (B16) Brake Switch Signal 2 circuit at the Stop Lamp Switch harness connector.

      Is there any voltage present?

      Yes 

      • Repair the (B16) Brake Switch 2 Signal circuit for a short to voltage.
      • Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  6
  6. CHECK THE (B16) BRAKE SWITCH 2 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Turn the ignition off.
    2. Disconnect the PCM C1 harness 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 the GPEC Diagnostic Adaptor to perform the diagnosis.

    3. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
    4. Measure the resistance of the (B16) Brake Switch 2 Signal circuit between the Brake Lamp Switch harness connector and the GPEC Adaptor.

      Is the resistance below 2.0 Ohms?

      Yes 

      • Go To  7

      No 

      • Repair the (B16) Brake Switch 2 Signal circuit for an open or high resistance.
      • Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  7. CHECK THE BRAKE LAMP SWITCH 
    1. Measure the resistance between terminal 3 and terminal 4 at the Stop Lamp Switch harness connector with the brake pedal NOT depressed.

      Is the resistance below 2.0 Ohms?

      Yes 

      • Replace and program the Powertrain Control Module in accordance with the service information.
      • Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Replace the Brake Lamp Switch in accordance with the service information.
      • Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  8. CHECK THE (Z908) GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Turn the ignition off.
    2. Disconnect the Brake Lamp Switch harness connector.
    3. Measure the resistance between ground and the (Z908) Ground circuit at the Brake Lamp Switch harness connector.

      Is the resistance below 5.0 Ohms?

      Yes 

      • Go To  9

      No 

      • Repair the (Z908) Ground circuit for an open or high resistance.
      • Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  9. CHECK THE (B15) BRAKE SWITCH 1 SIGNAL CIRCUIT VOLTAGE 
    1. Turn the ignition on.
    2. Measure the voltage on the (B15) Brake Switch Signal 1 circuit at the Brake Lamp Switch harness connector.

      Is the voltage reading approximately 12.0 volts?

      Yes 

      • Replace the Brake Lamp Switch in accordance with the service information.
      • Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  10
  10. CHECK THE (B15) BRAKE SWITCH 1 SIGNAL CIRCUIT FOR A SHORT TO GROUND 
    1. Turn the ignition off.
    2. Disconnect the PCM C1 harness connector.
    3. Measure the resistance between ground and the (B15) Brake Switch 1 Signal circuit at the Brake Lamp Switch harness connector.

      Is the resistance above 10k Ohms?

      Yes 

      • Go To  11

      No 

      • Repair the (B15) Brake Switch 1 Signal circuit for a short to ground.
      • Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  11. CHECK THE (B15) BRAKE SWITCH 1 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    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 the GPEC Diagnostic Adaptor to perform the diagnosis.

    1. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
    2. Measure the resistance of the (B15) Brake Switch 1 Signal circuit between the Brake Lamp Switch harness connector and the GPEC Adaptor.

      Is the resistance below 5.0 Ohms?

      Yes 

      • Replace the Powertrain Control Module in accordance with the service information.
      • Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Repair the (B15) Brake Switch 1 Signal circuit for an open or high resistance.
      • Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
scientia non olet · About LEMON Manuals