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. Remove the Brake Lamp Switch and disconnect the harness connector.
3. Measure the resistance between the (Z902) Ground circuit terminal and the (B15) Brake Lamp Switch Signal terminal at the Brake Lamp Switch.
4. Apply and release the brake pedal plunger 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 LAMP SWITCH SIGNAL CIRCUIT SHORT TO GROUND

Fig 1: Checking Brake Lamp Switch Signal Circuit
Courtesy of CHRYSLER LLC
1. Disconnect the PCM harness connectors.
2. Measure the resistance between ground and the (B15) Brake Lamp Switch Signal circuit in the Brake Lamp Switch harness connector.
  Is the resistance below 100 ohms?
  
  Yes
  - Repair the short to ground in the (B15) Brake Lamp Switch Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure
  No
  - Go To step 4
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 with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure