KNOCK IT OUT OF THE PARK
| Truck Trend Garage Knock It Out The Park
Question: I have a 2004 2WD Nissan Titan. Once in a while, I can't get the shifter out of Park. Then after a couple of tries, it works fine. I understand there is a switch or something that's activated by the brake that releases the shifter. Where and how do you override it so you can drive the truck when it acts up? Also what is it called?
Answer: All late-model vehicles (automatic transmission) are equipped with a safety device commonly referred to as shift lock or shift interlock. Its purpose is to prevent accidental shifting of the transmission out of Park, which can cause unwanted vehicle travel resulting in serious injury or death. It's a simple system that locks the shifter in Park until the brake pedal is depressed with the ignition in the On position. Basically, when the brake is applied, the brake switch (mounted at the pedal) sends 12 volts to the shift-lock solenoid located at the shifter assembly. The solenoid unblocks an opening in the shift plate, allowing the shifter release button to be fully depressed and the shifter moved to a desired gear. There is a secondary phase of these systems involving the ignition switch. In this case, it won't allow the driver to turn the ignition switch counterclockwise to the Off/Lock position while the transmission is in gear (out of Park). This prevents the driver from accidentally shutting off the engine, removing the key, and getting out of the vehicle while allowing it to roll freely-again, potentially causing serious injury or death. It also provides the added measure of preventing the shifter from being taken out of Park with the ignition in the Off position. All the shift lock systems have a manual override to prevent the driver from being stuck in the middle of nowhere when an electrical portion of the system fails. Typically, you'll find a small opening near the shifter where you can insert the ignition key or narrow screwdriver. Push, and allow the shifter release button to be depressed. On the 2004 Titan, check your owner's manual. Depending on floor or column shift, there may be a small plastic plug covering the override port, which must be removed before inserting the key to release the shifter. Also on the Titan, the shift lock solenoid must not only receive 12 volts from the brake switch, but also a ground path from the shift lock control unit. Diagnosing the circuit can be involved, but the most likely cause is the brake switch. This can sometimes be confirmed by observing the operation of the brake lights when the shift lock is on the fritz. Replace the switch if both are inoperative at the same time.
If you have a technical question regarding your pickup, SUV, or van, feel free to contact Alex, a master technician with the National Institute for Automotive Service Excellence. Send a letter to him in care of Truck Trend Garage, 831 S. Douglas Street, El Segundo, CA 90245, or e-mail us at trucktrend@sourceinterlink.com. Please include the VIN with your question. Due to the volume of questions received every month, we cannot guarantee that everyone's question will be personally answered or will appear in the magazine.
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