2009 Nissan Pathfinder Transmission Problems

Your vehicle suddenly stopped running while driving. When towed to a mechanic, they found that coolant had leaked into the transmission, causing damage. The transmission will likely need to be repaired or replaced, and the source of the coolant leak will need to be identified and fixed.

Your transmission suddenly failed while driving at highway speed with no warning signs. The problem was traced to a radiator failure that allowed coolant to leak into the transmission, causing permanent damage. Fixing this issue will require replacing the transmission, which is a major repair that typically costs around $4,000.

Your 2009 Nissan Pathfinder unexpectedly moved forward while parked in a parking lot, even though the gear was in Park. You had to press the brake pedal to stop it, and you were injured while getting into the vehicle. After this incident, the vehicle wouldn't start and had to be towed. The issue likely involves the transmission's park pawl mechanism or shift interlock system that's supposed to keep the vehicle stationary when in Park.

Your transmission fluid and engine coolant are mixing together inside your radiator, which contaminates the transmission fluid and causes overheating and transmission slipping. This happens because the transmission fluid cooler built into your radiator has failed, allowing the two fluids to combine. You may notice sudden jolts or slipping sensations while driving at any speed. The fix will likely involve replacing the radiator and flushing the transmission system to remove contaminated fluid.

When driving uphill on mountain roads, your transmission won't stay in the lower gears (2, 3, or 4) that you manually select. After a few minutes, it automatically shifts to 5th gear on its own and won't let you shift back down—you can only use Drive or stop the engine. The transmission shop has already replaced the shifting assembly and inspected the transmission and computer wires without finding the problem. The transmission works normally when driving downhill, making this difficult to diagnose. A transmission fluid flush and filter replacement might help, or the issue could require deeper computer/transmission control module diagnostics.

THE DEFECT IN THE RADIATOR CAUSED THE ANTIFREEZE AND OIL TO MIX. IT THEN MIXED WITH THE TRANSMISSION FLUID. THAT WAS FIXED BY A REPAIR SHOP. NOW THE TRANSMISSION HAS SLIPPED OUT BECAUSE OF THE MIXTURE OF THE THREE FLUIDS. *TR