Electronic Throttle Body Tests (2007-2009 3.5L Chevrolet Malibu And Pontiac G6)

TEST 4: Testing The TAC Motor

If you've reached this point, you have made sure that TPS 1 and TPS 2 are OK (not defective). In this test section, we're gonna' test the TAC motor.

The TAC motor is the one responsible for opening and closing the throttle plate when you step on or off the accelerator pedal.

What we're gonna' do is to make sure that the throttle actuator motor has not suffered an internal short-circuit or open-circuit problem.

If the throttle actuator motor has an internal short-circuit problem, you're gonna' see a resistance reading of under 1 Ohm.

If the throttle actuator motor has an internal open-circuit problem, you'll see a resistance reading in the thousands (K) of Ohms or the letters OL (if you're using a digital multimeter).

These are the test steps:

1. 1

   Disconnect the throttle body from its electrical connector.

2. 2

   Place your multimeter in Ohms mode.

3. 3

   Connect one multimeter test lead to terminal A and the other multimeter test lead to terminal B.

4. 4

   Your multimeter should read continuity.
   
   If the resistance reading is below 1 Ohm, then the motor has an internal short-circuit problem.
   
   If the resistance reading is in the K Ohms range or your multimeter reads OL, then the motor has an internal open-circuit problem.
   
   The resistance reading I've usually gotten from good throttle actuator motors has been between 1.6 to 12.0 Ohms.

Let's examine your test results:

CASE 1: The multimeter registered continuity between terminal A and B. This is the correct test result.

If your 3.5L V6 Chevy Malibu or Pontiac G6's electronic throttle body passed TEST 1 and TEST 2, then you can conclude that the electronic throttle body is OK and not defective.

CASE 2: The multimeter DID NOT register continuity. This lets you know that the TAC motor is defective. You'll need to replace the throttle actuator assembly.

More 3.5L V6 Chevy Malibu Tutorials

You can find a complete list of 3.5L V6 Chevy Malibu tutorials here: GM 3.5L V6 Index Of Articles.

Here's a list of articles you'll find there:

• How To Test The Engine Compression (2004-2007 3.5L Chevrolet Malibu).
• How To Do A Cylinder Balance Test (2004-2007 3.5L Malibu).
• How To Test A Blown Head Gasket (2004-2007 3.5L Malibu).
• How To Test The MAF Sensor (2004-2008 3.5L Malibu).