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Check Brake Pedal Switch Electrical System

Model: Jeep Grand Cherokee WK, MK 3, WH - Years 2004-2010
Part: Transmission

On all cars with automatic transmission, you must press the brake pedal to allow engine start and subsequently engage the gears. If pressing the brake pedal does not engage the gears and the rear brake lights do not illuminate, focus on the brake pedal switch and its wiring. Note that near the gear lever, there is a slot where you can press to unlock the safety and move the gear lever, in case you need to tow the car due to a breakdown. To carry out the various checks, it is advisable to have the vehicle wiring diagram available for consultation to go directly to the source of the problem. The first thing to check is the fuse protecting the brake switch: if it has blown and continues to blow even after replacement, there is likely a short circuit. Start by removing the rear lights to isolate that part of the system; if the problem persists, check the wiring of the power connector for the brake switch and finally the switch itself, testing its operation with a multimeter. If everything is functioning, examine the entire wiring diagram in detail as the anomaly may reside in the wireless system of the ignition switch: this is a known defect by the manufacturer on many Jeep-Dodge-Chrysler models and has been resolved free of charge even after the warranty has expired.

Updated on 15 February 2026 by ScegliAuto

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