GM 24203876
Speed Sensor

When changing the Vehicle Speed Sensor (VSS) in the 4L80-E automatic transmission you must first disconnect speed sensor wires before unscrewing bolts. First analyze vehicle speed sensor assemblies after removing them and their bracket constructions from the case. Reinstall the vehicle speed sensors and bracket assemblies onto the case according to the Fastener Notice in Service Precautions. Insert the 8mm socket into the bolts and fasten them to 11 Nm (96 inch lbs.) while reconnecting the speed sensor connections.

The replacement process for the Input Shaft Speed Sensor begins with properly raised vehicle support. Start by disconnecting the input speed sensor electrical connector followed by input speed sensor bolt removal and finally the input speed sensor itself can be taken out. Check the input speed sensor for any noticeable signs of damage. Lubricate the input speed sensor seal with automatic transmission fluid before you install the input speed sensor. Use 11 Nm torque (96 inch lbs.) when tightening the input speed sensor bolt. After securing the input speed sensor electrical connector you should lower the vehicle.

The first step to replace Vehicle Speed Sensor (VSS) involves properly lifting the car. Use a screwdriver to disconnect the electrical connector from the input speed sensor before removing the bolt and separating the input speed sensor and its bracket from the vehicle case. Check the vehicle speed sensor assembly for any detectable damage. Apply Automatic Transmission Fluid to the input speed sensor seal before installing the input speed sensor and the bracket assembly. Install the bolt, tightening it to 11 Nm (96 inch lbs.)Reconnect the input speed sensor electrical connector and then safely lower the vehicle.

Install the bolt and tighten it to 11 Nm (97 inch lbs.).

Lower the vehicle.

Lubricate the output speed sensor seal with automatic transmission fluid.

Raise and suitably support the vehicle.

Place a new O-ring seal on the speed sensor and install it, tightening the sensor to 17 Nm (13 ft. lbs.).

Tighten it to 11 Nm (96 inch lbs.).

Reconnect the output speed sensor electrical connector before lowering the vehicle.

Disconnect the right rear speed sensor electrical connector and remove the right rear speed sensor.

Install the VSS bolt and tighten it to 11 Nm (97 inch lbs.).

Reconnect the front speed sensor electrical connector and reinstall the transfer case shield if it is equipped.

Remove the input speed sensor bolt and the input speed sensor.

Reconnect the speed sensor electrical connector and lower the vehicle.

Reconnect the electrical connector to the speed sensor and lower the vehicle.

Reinstall the transfer case shield if it is equipped.

First, raise the vehicle.

Remove the bolt and take out the speed sensor along with the O-ring seal.

Finally, reconnect the electrical connector to the speed sensor and lower the vehicle.

Disconnect the input speed sensor electrical connector and remove the input speed sensor bolt.

Take out the speed sensor along with the O-ring seal, and inspect both the seal and the transmission case.

Raise the vehicle.

First, raise the vehicle.

Lubricate the output speed sensor seal with automatic transmission fluid.

Install the bolt, ensuring it is tightened to 11 Nm (96 inch lbs.).

Install the speed sensor and the O-ring seal back into the transmission, ensuring to follow the Fastener Notice in Service Precautions.

Disconnect the input speed sensor electrical connector and remove the input speed sensor bolt.

Reconnect the electrical connector to the speed sensor before lowering the vehicle.

Raise the vehicle.

Tighten it to 15 Nm (11 ft. lbs.).

Disconnect the VSS electrical connector and remove the VSS along with its seal.

Inspect the output speed sensor for any signs of damage.

First, raise and suitably support the vehicle.

Do not rotate it in its retaining bracket to avoid improper operation.

First, remove the transfer case shield if it is equipped.

Raise and suitably support the vehicle.

Coat the new O-ring seal with a thin film of transmission fluid, using GM P/N 12346190 (Canadian P/N 10953477) or an equivalent.

Remove the bolt securing the speed sensor and carefully take out the speed sensor.

The output speed sensor is located on the transfer case.

Ensure the vehicle ignition is off and disconnect the external wiring harness from the speed sensor.

Inspect the input speed sensor for any evidence of damage.

Place the vehicle speed sensors and the bracket assemblies back onto the case, ensuring to follow the Fastener Notice in Service Precautions.

Connect the right rear speed sensor electrical connector and lower the vehicle.

Take out the input speed sensor along with the bracket assembly from the case and inspect the vehicle speed sensor assembly for any signs of damage.

Ensure to follow the fastener notice in service precautions.

Disconnect the VSS electrical connector.

Reconnect the speed sensor electrical connector and reinstall the transfer case shield if it was removed.

Lubricate the output speed sensor seal with automatic transmission fluid.

Disconnect the output speed sensor electrical connector.

Disconnect the left rear speed sensor electrical connector and remove the left rear speed sensor.

Inspect the output speed sensor assembly for any signs of damage.

Tighten it to 15 Nm (11 ft. lbs.).

Tighten it to 17 Nm (13 ft. lbs.).

First, raise the vehicle.

Secure the sensor with the bolt, tightening it to 11 Nm (97 inch lbs.).

Reconnect the output speed sensor electrical connector and lower the vehicle.

Remove the output speed sensor bolt.

The bolts should be tightened to 11 Nm (96 inch lbs.).

Disconnect the electrical connector from the speed sensor and remove the speed sensor along with the O-ring from the transfer case.

The output speed sensor for 4WD vehicles is located on the transfer case.

Reconnect the VSS electrical connector, lower the vehicle, and refill the fluid as required.

Raise the vehicle and disconnect the input speed sensor electrical connector.

Reconnect the electrical connector to the speed sensor before lowering the vehicle.

First, raise and support the vehicle appropriately.

For 4WD vehicles, the output speed sensor is located on the transfer case.

Remove the VSS bolt and the VSS.

Ensure the vehicle ignition is off and disconnect the external wiring harness from the speed sensor.

Coat a NEW O-ring seal with a thin film of Synchro-mesh transmission fluid GM P/N 12345349 (Canadian P/N 10953465) or equivalent.

Install the bolt, ensuring it is tightened to 11 Nm (96 inch lbs.), and reconnect the output speed sensor electrical connector.

Install the VSS and secure it with the VSS bolt, tightening it to 11 Nm (97 inch lbs.).

Raise and support the vehicle.

Reinstall the transfer case shield if it is equipped.

Disconnect the left rear speed sensor electrical connector and remove the left rear speed sensor.

Remove the VSS bolt and the VSS.

Lubricate it with transmission fluid.

Reconnect the left rear speed sensor electrical connector and lower the vehicle.

Install the input speed sensor and the bracket assembly, then install the bolt and tighten it to 11 N.m (96 lb in).

Disconnect the input speed sensor electrical connector.

Connect the wiring harness electrical connector to the vehicle speed sensor and refill the fluid as required.

Ensure to tighten the bolt to 16 Nm (12 ft. lbs.).

Disconnect the VSS electrical connector and remove the VSS along with the O-ring seal.

Connect the input speed sensor electrical connector and lower the vehicle.

Reconnect the VSS electrical connector, lower the vehicle, and refill the fluid as required.

Raise and suitably support the vehicle.