Fault Code 24


Description:  Throttle position sensor (TPS) signal is out of range
Power loss light:  On
Limp-in mode: MAP sensor is used as an indication of thottle position

Possible Causes

TPS failure - The TPS is located on the throttle body on the opposite side of the throttle cable.  Turn the engine off, disconnect the sensor and test it by connecting an ohmmeter (preferably an analog one) between the center and either outside pin of the sensor.  Slowly open the throttle all the way and then slowly close it again.  The ohmmeter should show a constant, smooth change in resistance as the throttle is moved.  If there are any jumps in reading or no change in reading at all, replace the sensor.  If the sensor seems ok, reconnect the sensor cable and turn the ignition on.  One outside wire should be 5V, the other ground.  The voltage on the center wire should vary as the throttle is opened (about 0V closed, 3V wide open).  If power or ground is not present, check the wiring.

Bad connection or wiring - Check the wiring and connections between the sensor and the logic module (or SMEC).  Clean and regrease any corroded connectors with dielectric grease.  Check connections if there is no power or ground, or for shorts if there is power and resistance, but no output.

Diagnostic Method

Trigger Parameters

- Sensor output less than 0.16V or greater than 4.7V

Results If Component Fails

Fault code 24 is stored, the power loss light is turned on, and the logic module will enter limp-in mode.  The logic module will then use the MAP sensor as an indication of the thottle position.  A MAP sensor voltage less than 2.0V is considered closed throttle and a MAP sensor voltage greater than 2.0V is considered wide open throttle (WOT).
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This page is maintained by Russell W. Knize and was last updated 08/28/98. Comments? Questions? Send email.

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