GM Blazer/Jimmy/Typhoon/Bravada 1983-1993 Repair Guide

Throttle Position (TP) Sensor


See Figures 1 and 2

The TP sensor is connected to the throttle shaft of the throttle body or carburetor. It is a potentiometer with one end connected to 5 volts from the control module and the other to ground. A third wire is connected to the control module in order to measure voltage from sensor. As the throttle angle is changed (the accelerator is pressed down), the output of the sensor changes.

At a closed throttle the output of the sensor is fairly low (0.5 V). As the throttle opens, the output voltage should rise towards 5 V. By monitoring the sensor output voltage the control module can determine fuel delivery based on throttle angle.

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Fig. Fig. 1: Common throttle position sensor - carbureted vehicles

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Fig. Fig. 2: Common throttle position sensor - TBI vehicles


  1. Disconnect the negative battery cable.
  3. Remove the air cleaner assembly or air duct, if necessary for access.
  5. Disengage the TP sensor electrical wiring connector.
  7. Loosen and remove the sensor attaching screws.
  9. Remove the sensor from the carburetor or throttle body.

To install:
  1. If equipped, position the seal over the throttle shaft.
  3. Make sure the throttle valve is closed, then position the sensor over the shaft.

On most applications, it will be necessary to rotate the sensor counterclockwise to align the bolt holes.

  1. Make sure the retainers are covered with a suitable thread-locking compound (Loctite®262 or equivalent) then install the bolts and tighten to 18 inch lbs. (2 Nm).

Some earlier model vehicles, such as some applications of the 2.8L engine, utilize an adjustable TP sensor. If so equipped, the sensor should be adjusted after the retainers are threaded, but BEFORE they are tightened. Please refer to Fuel System in this repair guide for TP sensor adjustment procedures.

  1. Engage the sensor electrical connector.
  3. If removed, install the air cleaner assembly or duct, as applicable.
  5. Connect the negative battery cable and check for proper operation. Please refer to Fuel System of this repair guide for testing.