GM 19302667 Sensor Asm,Vehicle Speed

There are various electric-shift transfer cases on the models covered, along with several combinations of speed sensors available. The Vehicle Speed Sensor (VSS) transmits information to the PCM for the driveability program and is positioned at the rear output shaft. The process for checking and replacing the output shaft speed sensor is similar to that of the VSS. A scan tool is necessary to access speed sensor data and trouble codes. It is important to always use a new O-ring when installing the VSS, and the O-ring should be lubricated with DEXRON VI (or equivalent) transmission fluid prior to installation.

The Vehicle Speed Sensor (VSS) is a permanent magnet generator mounted on the transmission. It is triggered by a toothed rotor on the transmission output shaft. As the output shaft rotates, the sensor produces an AC voltage, the frequency of which is proportional to vehicle speed. The PCM uses the sensor input signal for several different engine, transmission and radio control functions. The VSS signal also drives the speedometer on the instrument panel. A defective VSS can cause various driveabilily and transmission problems. To replace it, raise the vehicle and support it securely on jackstands. Disconnect the electrical connector from the VSS, which is located on the right side of the extension housing on automatic transmission models and on the left side of the extension housing on manual transmissions. Remove the mounting bolt and withdraw the VSS from the transmission case. Replace the sensor O-ring and lubricate it with clean transmission fluid. Installation is the reverse of removal.

There are a variety of electric-shift transfer cases on the models covered and several different combinations of speed sensors are available. The Vehicle Speed Sensor (VSS) sends information to the PCM for the driveability program and is located at the rear output shaft. The procedure for checking and replacement of the output shaft speed sensor is essentially the same as the procedure for the Vehicle Speed Sensor (VSS). A scan tool must be used to access speed sensor data and trouble codes.

The camshaft sensor and crankshaft sensor, depending on the engine type, should be checked for resistance and proper signal output.

A scan tool is required to access speed sensor data and trouble codes.

When installing the VSS, a new O-ring should be used, even if the old VSS sensor is being reused.

After replacing the sensor, check the transmission fluid level and add fluid if necessary.

First, disconnect the electrical connector and remove the sensor mounting bolt. Then, remove the VSS mounting bolt and take out the VSS from the transmission. If it's difficult to remove, wiggle it from side-to-side while pulling it out.

Turn off the ignition key and disconnect the electrical connector from the sensor. Use an ohmmeter to measure the resistance across the two terminals, which should be approximately 1,000 to 3,000 ohms at 68-degrees F.

The VSS is located at the rear output shaft.

The oxygen sensor in the exhaust monitors oxygen content. To check it, you can check its millivolt signal while the engine warms up. It is also important to inspect the oxygen sensor heater and ensure it receives proper voltage.

On 2WD models, the VSS hold-down bolt should be removed and the VSS should be taken out from the transmission.

The second speed sensor is located at the rear output shaft.

The VSS signal drives the speedometer on the instrument panel.

The VSS sends information to the PCM for the driveability program.

This manual covers models with various electric-shift transfer cases and different combinations of speed sensors.

To install the VSS, the removal steps should be reversed and the VSS hold-down bolt (2WD models) or the VSS (4WD models) should be tightened securely.

When installing the VSS, a new O-ring should be used, even if the old VSS sensor is being reused.

The Vehicle Speed Sensor (VSS) is a permanent magnet generator mounted on the transmission.

The old O-ring from the VSS should be removed and discarded.

The old O-ring from the VSS should be removed and discarded.

A scan tool is required to access speed sensor data and trouble codes.

If any component fails these checks, replacement may be necessary.

The intake air temperature (IAT) sensor acts as a thermistor. To check it, you can measure its resistance at different temperatures to ensure it changes as expected. Additionally, you should monitor the IAT sensor using a scan tool to verify its performance.