Diagnostic Test

1) ACTIVE DTC
Ignition on, engine not running.

With a scan tool, read DTCs.

Is the DTC active at this time?

Yes
1. Go to 2).
No

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1. Perform INTERMITTENT CONDITION Diagnostic Procedure. Refer to INTERMITTENT CONDITION .
2. Perform POWERTRAIN VERIFICATION TEST .
2) BRAKE LAMP SWITCH OPERATION
Turn the ignition off.

Remove the Brake Lamp Switch and disconnect the harness connector.

Measure the resistance between the (Z902) Ground circuit terminal and the (B15) Brake Lamp Switch Signal terminal at the Brake Lamp Switch.

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
1. Go to 3).
No
1. Replace the Brake Lamp Switch.
2. Perform POWERTRAIN VERIFICATION TEST .
3) (B15) BRAKE LAMP SWITCH SIGNAL CIRCUIT SHORT TO GROUND

Fig 1: Measuring Resistance Between Ground & Brake Lamp Switch Signal Circuit
Courtesy of CHRYSLER LLC

Disconnect the PCM harness connectors.

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
1. Repair the short to ground in the (B15) Brake Lamp Switch Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go to 4).
4) PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

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