How to Locate the Barometric Sensor in a 2003 VW Jetta
The 2003 Volkswagen Jetta base model, either as a sedan or station wagon, came with a 2.0-liter in-line four-cylinder engine and a five-spee...
The 2003 Volkswagen Jetta base model, either as a sedan or station wagon, came with a 2.0-liter in-line four-cylinder engine and a five-speed manual transmission. Your Jetta's computer is able to detect engine load based on the amount of vacuum created by the engine. Volkswagen integrated a manifold absolute pressure sensor, or MAP sensor that measures the difference in pressure. If this sensor fails, your engine will run rough and erratically.
Instructions
- 1
Park the vehicle on a level surface and set the parking brake. Lift the hood and support it with the hood prop rod. Examine the passenger side of the engine and locate the alternator on the front side of the engine. Look directly above the alternator pulley to find the MAP sensor attached to the plastic intake air tube.
2Squeeze the locking tab for the MAP sensor wiring harness and carefully pull the harness away from the MAP sensor. Remove the two Phillips head screws securing the MAP sensor to the intake tube with a Phillips head screwdriver. Pull the MAP sensor out of the intake air tube.
3Inspect the old map sensor and verify the original O-ring was removed with the sensor. Remove the O-ring from the intake tube with a pick tool, if it was not removed with the sensor.
4Install the new O-ring onto the recess at the tip of the new MAP sensor and apply a thin coat of fresh 5w-30 engine oil over the O-ring. Push the tip of the MAP sensor into the intake tube and align the mounting holes with the holes on the intake tube. Install the MAP sensor mounting screws and tighten snug with a Phillips head screwdriver.
5Plug the wiring harness into the MAP sensor, then pull on the plastic connector lightly to ensure it is properly connected. Inspect the harness wiring to make sure it is not to close to, or touching, the serpentine belt or alternator pulley. Tie the harness to the intake tube with a large zip strip or cable tie, if it hangs too low. Shut the vehicle hood and clear any stored trouble codes, using an ODBII scan tool.
