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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 209 (ENGINE CONTROLS - THEORY & OPERATION - 6.6L Diesel) >> Computerized Engine Controls >> Input Devices >> Accelerator Pedal Position Sensor

Accelerator Pedal Position Sensor

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The Accelerator Pedal Position (APP) system along with the vehicle electronics and components is used to calculate and control the amount of acceleration and deceleration via fuel injector control. This eliminates the need for a mechanical cable attachment from the accelerator pedal to a throttle body. The APP system includes, but is not limited to the APP sensor assembly and ECM.

The APP sensor is mounted on the accelerator pedal control assembly. See Fig 1 . The sensor is made up of 3 individual sensors within one housing. Three separate signal, low reference, and 5-volt reference circuits are used in order to interface the accelerator pedal sensor assembly with the ECM. Each sensor has a unique functionality to determine pedal position. ECM uses the APP sensor to determine the amount of acceleration or deceleration desired by the person driving the vehicle. The APP sensor 1 voltage should increase as the accelerator pedal is depressed, from less than 1.0 volt at zero pedal travel to greater than 2 volts at 100 percent pedal travel. APP sensor 2 voltage should decrease from greater than 4 volts at zero pedal travel to less than 3 volts at 100 percent pedal travel. APP sensor 3 voltage should decrease from greater than 3.8 volts at zero percent pedal travel to less than 3.3 volts at 100 percent pedal travel.

Fig 1: Locating Accelerator Pedal Position Sensor
G00148208Courtesy of GENERAL MOTORS CORP.