APP Sensor Tests (2004 4.2L Oldsmobile Bravada, 2004-2007 4.2L Buick Rainier)

TEST 2: APP Sensor 1 Resistance Tests (2 Of 2)

APP Sensor 1 Resistance Tests (2 Of 2). How To Test The APP Sensor Assembly (2004 4.2L Oldsmobile Bravada And 2004, 2005, 2006, 2007 4.2L Buick Rainier)

For your second APP sensor 1 test, you'll test the resistance of the circuit between terminals E and F while you depress and release the accelerator pedal.

If all is good with the circuit, your multimeter should report:

  • The resistance decreases as you depress the accelerator pedal.
  • The resistance increases as you release the accelerator pedal.

Generally, if the circuit is fried you'll see the resistance value stay stuck in one value as you depress/release the accelerator pedal.

Let's get this show on the road:

  1. 1

    Disconnect the APP sensor assembly from its electrical connector.

  2. 2

    Place your multimeter in Ohms mode.

  3. 3

    Connect one multimeter test lead to terminal E.

  4. 4

    Connect the other multimeter test lead to terminal F.

  5. 5

    Note the Ohms reading on your multimeter.

    At this point you'll see a resistance reading somewhere around 3K Ohms.

    If you don't, don't worry. Continue to the next step.

  6. 6

    Slowly depress the pedal by hand till it bottoms out.

  7. 7

    The resistance value should decrease as you depress the pedal.

  8. 8

    Slowly release the accelerator pedal.

  9. 9

    The resistance value should increase back to the original value you saw in step 5.

Let's examine your test results:

CASE 1: The resistance decreased/increased without any gaps. This is the correct test result.

The next step is testing APP sensor 2. Go to: TEST 3: APP Sensor 2 Resistance Tests (1 Of 2).

CASE 2: The resistance DID NOT decrease. This lets you know APP sensor 1 is bad.

Replace the accelerator pedal assembly.

CASE 3: The resistance DID NOT increase. This lets you know APP sensor 1 is bad.

Replace the accelerator pedal assembly.

CASE 4: The resistance DID NOT decrease/increase. This lets you know APP sensor 1 is bad.

Replace the accelerator pedal assembly.

TEST 3: APP Sensor 2 Resistance Tests (1 Of 2)

APP Sensor 2 Resistance Tests (1 Of 2). How To Test The APP Sensor Assembly (2004 4.2L Oldsmobile Bravada And 2004, 2005, 2006, 2007 4.2L Buick Rainier)

So far, your test results have confirmed that APP sensor 1 is OK. Now, you'll focus on APP sensor 2 by testing the circuit between male spade terminals A and C (see the illustration above).

What you're looking for is for your multimeter to report continuity in the circuit between terminals A and C.

Specifically, your multimeter should report a resistance value somewhere around 3K to 4K Ohms.

If there's a problem with the circuit, you'll usually see your multimeter report a short-circuit or an open-circuit problem.

  • Terminal G receives 5 Volts DC from the PCM.
  • Terminal J receives Ground from the PCM.

Let's get testing:

  1. 1

    Disconnect the APP sensor assembly from its electrical connector.

  2. 2

    Place your multimeter in Ohms mode.

  3. 3

    Connect one multimeter test lead to terminal G.

  4. 4

    Connect the other test lead to terminal J.

  5. 5

    Your multimeter should read continuity.

    You should see an Ohms reading somewhere between 3K to 4K Ohms.

Let's examine your test results:

CASE 1: The multimeter registered continuity between terminals A and C. So far so good, since this is the correct test result.

Your next step is testing the resistance of APP sensor 2 while depressing/releasing the accelerator pedal. Go to: TEST 4: APP Sensor 2 Resistance Tests (2 Of 2).

CASE 2: The multimeter registered 0 Ohms (or a value very close to it) between terminals A and C. This test result confirms a short-circuit problem between terminals A and C.

With this test result, you can conclude the accelerator pedal assembly is defective and needs replacement.

CASE 3: The multimeter reports no continuity (the letters OL are displayed) between terminals A and C. This test result confirms an open-circuit problem between terminals A and C.

With this test result, you can conclude the accelerator pedal assembly is defective and needs replacement.

Buick Vehicles:

  • Rainier 4.2L
    • 2004, 2005, 2006, 2007

Oldsmobile Vehicles:

  • Bravada 4.2L
    • 2004