Contents: Examination ⇊ Replacement ⇊
The VSS is mounted on the transmission case and is a variable magnetic resistance sensor that begins to generate voltage pulses as soon as the vehicle speed exceeds 4.8 km/h (3 mph). The pulses from the sensor are sent to the PCM and are used by the module to control the duration of the fuel injector opening time and transmission shifting. On models with a manual transmission, one VSS is used, on models equipped with an automatic transmission, two speed sensors are provided: one is connected to the secondary shaft of the gearbox, the second - to the intermediate shaft, and the failure of either of them leads to problems with transmission shifting.
Examination
Models with manual transmission
1. Disconnect the sensor wiring harness connector. Measure the voltage at the connector (harness side) with a voltmeter. The positive probe of the voltmeter should be connected to the black-yellow wire terminal, the negative probe to ground. There should be battery voltage at the connector. If there is no power, check the condition of the VSS wiring between the sensor and the fuse box (on the left under the instrument panel). Also make sure that the fuse itself is in good condition. Use an ohmmeter to check for continuity between the connector's black wire terminal and ground. If there is no continuity, check the condition of the black wire and the quality of its terminal connections.
2. Jack up the front of the vehicle and place it on stands. Chock the rear wheels and shift the transmission into neutral. Connect the wiring to the VSS, turn on the ignition (do not start the engine) and test the signal (blue-white) wire terminal on the back of the connector with a voltmeter (connect the negative probe to the body ground). Keeping one of the front wheels stationary,
manually rotate the opposite one, the voltage should fluctuate between zero and 5V, otherwise replace VSS.
Models with AT
3. Disconnect the wiring from the corresponding speed sensor. Using an ohmmeter, measure the resistance between the two sensor terminals. The nominal value is approximately 400÷600 Ohm, otherwise replace the sensor.
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Replacement
1. Disconnect the electrical wiring from the speed sensor.
2. Loosen the mounting screw and remove the sensor from the transmission housing.
3. Installation is carried out in the reverse order. Do not forget to replace the sealing ring.