C0357

Step 1: Locate the park/parking brake switch (typically on brake pedal assembly, center console, or lever assembly) and visually inspect the switch, connector, and associated wiring for obvious damage, corrosion, chafing, or signs of water intrusion

Step 2: Using a digital multimeter, backprobe the park switch signal wire at the switch connector with key on, engine off. Measure voltage and verify reading (should typically be 0-2V released, 5-12V applied depending on system design). A constant high voltage (near battery voltage) confirms circuit fault

Step 3: Disconnect the park brake switch connector and measure voltage at the control module side of the harness. If high voltage persists with switch disconnected, wiring is shorted to power between switch and module; if voltage drops to normal, switch is faulty

Step 4: Inspect wiring harness routing from switch to EBCM/BCM for pinch points, contact with hot components, or areas where wire insulation may be compromised. Pay special attention to areas near moving components or sharp metal edges

Step 5: If wiring and switch test normal, check park switch ground circuit for continuity and proper ground connection. Measure resistance from ground pin to chassis ground (should be less than 1 ohm)

Step 6: Replace faulty component (switch, repair wiring, or replace control module if internal fault confirmed), clear codes, cycle parking brake through full range of operation multiple times, and verify code does not return with test drive