Diagnostic Test

ACTIVE DTC
NOTE: Make sure the Stop Lamp Switch is properly adjusted before continuing.

NOTE: Make sure the Stop Lamp Switch is properly wired, such as (B15) Brake Switch No. 1 and (B16) Brake Switch No. 2 Signal circuit are not switched at the harness connector.
1. Ignition on, engine not running.
2. With a scan tool, select View DTCs.
3. Press and release the Brake Pedal.
  Is the DTC Active at this time?
  
  Yes
  - Go to step 2
  No
  - Refer to the INTERMITTENT CONDITION Diagnostic Procedure. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(B15) BRAKE SWITCH NO. 1 SIGNAL SHORTED TO GROUND

Fig 1: Checking Brake Switch Signal
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the Stop Lamp Switch harness connector.
3. Disconnect the C3 PCM harness connector.
4. Measure the resistance between ground and the (B15) Brake Switch No. 1 Signal circuit in the Stop Lamp Switch harness connector.
  Is the resistance below 100 ohms?
  
  Yes
  - Repair the short to ground in the (B15) Brake Switch No. 1 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 3
(B16) BRAKE SWITCH NO. 2 SIGNAL CIRCUIT OPEN

Fig 2: Checking Brake Switch Signal
Courtesy of CHRYSLER LLC
1. Disconnect the C3 PCM harness connector.
2. Measure the resistance of the (B16) Brake Switch No. 2 Signal circuit from the Stop 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 (B16) Brake Switch No. 2 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(B16) BRAKE SWITCH NO. 2 SIGNAL CIRCUIT SHORTED TO GROUND

Fig 3: Checking Brake Switch Signal
Courtesy of CHRYSLER LLC
1. Measure the resistance between ground and the (B16) Brake Switch No. 2 Signal circuit in the Stop Lamp Switch harness connector.
  Is the resistance below 100 ohms?
  
  Yes
  - Repair the short to ground in the (B16) Brake Switch No. 2 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 5
(Z904) GROUND CIRCUIT OPEN

Fig 4: Checking Ground Circuit
Courtesy of CHRYSLER LLC
1. Measure the resistance between ground and the (Z904) Ground circuit in the Stop Lamp Switch harness connector.
  Is the resistance below 5.0 ohms?
  
  Yes
  - Go to step 6
  No
  - Repair the open in the (Z904) Ground circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
STOP LAMP SWITCH
1. Measure the resistance between the (Z904) Ground circuit terminal and the (B15) Brake Switch No. 1 Signal terminal in the Stop Lamp Switch.
2. Next, measure the resistance between the (F942) Fused Ignition Switch Output circuit terminal and the (B16) Brake Switch No. 2 Signal circuit terminal in the Stop Lamp Switch.
3. Apply and release the Stop Lamp Switch while monitoring the ohmmeter.
  Does the resistance change from below 5.0 ohms to an open circuit for one or both of the measurements taken?
  
  Yes
  - Go to step 7
  No
  - Verify that there is good pin to terminal contact in the Switch and Powertrain Control Module connectors. If OK, replace the Stop Lamp Switch.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Stop Lamp Switch and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Switch and Powertrain Control Module connectors.
4. Refer to any Technical Service Bulletins that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Replace and program the Powertrain Control Module per Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .