Diagnostic Test

ACTIVE DTC
1. Ignition on, engine not running.
2. With a scan tool, read DTCs.
  Is the DTC active at this time?
  
  Yes
  - Go to step 2
  No
  - Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure
BRAKE LAMP SWITCH OPERATION
1. Turn the ignition off.
2. Disconnect the Brake Lamp Switch harness connector.
3. Measure the resistance between the (Z902) Ground circuit terminal and the (B15) Brake Switch Signal circuit terminal in the Brake Lamp Switch.
4. Apply and release the brake pedal while monitoring the ohmmeter.
  Does the resistance change from below 5.0 ohms to an open circuit?
  
  Yes
  - Go To step 3
  No
  - Replace the Brake Lamp Switch.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure
(B15) BRAKE SWITCH SIGNAL CIRCUIT OPEN

Fig 1: Checking Brake Switch Signal Circuit
Courtesy of CHRYSLER LLC
1. Disconnect the PCM harness connectors.
  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 PCM Pinout Box 8815 to perform diagnosis.
2. Measure the resistance of the (B15) Brake Switch Signal circuit from the Brake Lamp Switch harness connector to the appropriate terminal of special tool #8815.
  Is the resistance below 5.0 ohms?
  
  Yes
  - Go To step 4
  No
  - Repair the open in the (B15) Brake Switch Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure
GROUND CIRCUIT OPEN

Fig 2: Checking Ground Circuit
Courtesy of CHRYSLER LLC
1. Measure the resistance between the (Z902) Ground circuit and ground at the Brake Lamp Switch harness connector.
  Is the resistance below 5.0 ohms?
  
  Yes
  - Go To step 5
  No
  - Repair the open in the (Z902) Ground circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure
PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
1. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
  If there are no possible causes remaining, view repair.
  
  Repair
  - Replace and program the Powertrain Control Module in accordance Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure