APP sensor resistance tests with Multimeter.

If you've been searching for a simple resistance test and specification tutorial for the Accelerator Pedal Position (APP) Sensors (APP 1, APP 2, and APP 3)... then you've found it here.

In this tutorial, I'm gonna' present to you my ‘Cheat Sheet’ of resistance values that I use to quickly test all three of the Accelerator Pedal Position (APP) sensors inside the APP Assembly.

This tutorial complements these tutorials (which are also found here at easyautodiagnostics.com):

APP Sensor

  1. How to Test the GM Accelerator Pedal Position (APP) Sensor 1.
  2. How to Test the GM Accelerator Pedal Position (APP) Sensor 2.

TPS Sensor

  1. Resistance Specifications of the TAC Electronic Throttle Body
  2. GM Electronic Throttle Body Circuit Descriptions and Testing Tips.
  3. Cleaning the GM Electronic Throttle Body (4.8L, 5.3L, 6.0L).
  4. P0120 TP Sensor 1 Circuit Malfunction (with Electronic Throttle Body).
  5. P0220 TP Sensor 2 Circuit Malfunction (with Electronic Throttle Body).

En Español Puedes encontrar este tutorial en Español aquí: Especificaciones de los Sensores de Posición del Pedal del Acelerador (en: autotecnico-online.com).

What Tools Do I Need?

Digital Multimeter with Bar Graph

The most important tool you're gonna' need is a multimeter... but not just any type of multimeter...

...You need to use a digital multimeter with a bar graph or an analog multimeter (this is a multimeter with a needle). The digital multimeter with a bar graph simulates the needle of the analog multimeter.

Here's why:

  1. A digital multimeter without a bar graph will not respond fast enough to the changes in resistance.
  2. A digital multimeter without a bar graph will display gaps in the Ohms values, as you manually depress and release the accelerator pedal. These gaps, in the Ohms values registered, can lead you to believe that APP Sensor 1 (or APP Sensor 2 or APP Sensor 3) is BAD when it isn't.
    1. The Fluke 115 digital multimeter has a bar graph... to see it, check out this article: Abe's Multimeter Recommendation.
    2. You can use an analog multimeter too.
  3. An analog multimeter will be able to follow the depressing and releasing of the accelerator pedal easily.
  4. If the needle jerks (does not have a fluid upward movement), then this signifies a problem.

Resistance Specification ‘Cheat Sheet’

APP sensor resistance tests with Multimeter.

These are the resistance specifications of APP Sensor 1, APP Sensor 2, and the APP Sensor 3. I took these from a working APP Sensor Assembly.

APP Sensor 1 Resistance Specs.
Pin Description
G & F 5.03 K Ω  - Pedal at Rest (not depressed)
G: 5 Volt Circuit
F: Position Signal Circuit
G & F 2.98 K Ω  - Pedal completely depressed
G: 5 Volt Circuit
F: Position Signal Circuit
NOTE: As you manually depress and release the accelerator pedal, your multimeter should swing its needle (or bar graph) smoothly and without stops or gaps in the movement.
E & F 2.58 K Ω  - Pedal at Rest (not depressed)
E: Ground Circuit
F: Position Signal Circuit
E & F 4.58 K Ω  - Pedal at Rest (not depressed)
G: Ground Circuit
F: Position Signal Circuit

APP Sensor 2 Resistance Specs.
Pin Description
C & D 1.34 K Ω  - Pedal at Rest (not depressed)
C: Position Signal Circuit
D: 5 Volt Circuit
C & D 3.23 K Ω  - Pedal completely depressed
C: Position Signal Circuit
D: 5 Volt Circuit
NOTE: As you manually depress and release the accelerator pedal, your multimeter should swing its needle (or bar graph) smoothly and without stops or gaps in the movement.
B & C 3.73 K Ω  - Pedal at Rest (not depressed)
B: Ground Circuit
C: Position Signal Circuit
B & C 1.75 K Ω  - Pedal at Rest (not depressed)
B: Ground Circuit
C: Position Signal Circuit

APP Sensor 3 Resistance Specs.
Pin Description
K & J No Info  - Pedal at Rest (not depressed)
K: Position Signal Circuit
J: 5 Volt Circuit
K & J No Info  - Pedal completely depressed
K: Position Signal Circuit
J: 5 Volt Circuit
NOTE: The APP Sensor Assembly that I was testing did not have APP Sensor 3 inside the assembly.
A & K No Info  - Pedal at Rest (not depressed)
A: Ground Circuit
K: Position Signal Circuit
A & K No Info  - Pedal at Rest (not depressed)
A: Ground Circuit
K: Position Signal Circuit