How To Test The Electronic Throttle Body (2007, 2008, 2009 3.5L (N) Chevrolet Malibu and 3.5L (N) Pontiac G6)

Testing the electronic throttle body on the 2007-2009 3.5L V6 (N) Chevrolet Malibu or 2007-2010 3.5L V6 (N) Pontiac G6 can seem next to impossible but it really isn't difficult at all.

In this tutorial I'm gonna' explain how to resistance test TPS 1, TPS 2, and the TAC motor using a multimeter. With your tests results you'll able to find out if the electronic throttle body is defective or not.

NOTE: This tutorial applies to the 2007, 2008, 2009 3.5L V6 (N) Chevrolet Malibu and 2007, 2008, 2009, and 2010 3.5L V6 (N) Pontiac G6.

youtube video See my YouTube video of this tutorial here: How To Test The Electronic Throttle Body. GM Vehicles 2006-2011.

You can find this tutorial in Spanish here: Probando El Cuerpo Del Acelerador Electr├│nico (2007-2009 3.5L Chevrolet Malibu y Pontiac G6) (at: autotecnico-online.com).

NOTE: You can find the TAC system wiring diagram here: TAC Circuit Wiring Diagram (2007-2009 3.5L Chevy Malibu And Pontiac G6).

You can find a basic operating theory explanation of the electronic throttle body here: Electronic Throttle Body Basics (2007-2009 3.5L Chevy Malibu and Pontiac G6).

Symptoms Of A Bad Electronic Throttle Body

You're gonna' see one or more of the following symptoms when the electronic throttle body fails:

  1. The check light engine light will be lit up by one of the following trouble codes:
    1. P0121: Throttle Position Sensor (TPS) Sensor 1 Perfomance.
    2. P0122: Throttle Position Sensor (TPS) Sensor 1 Circuit Low Voltage.
    3. P0123: Throttle Position Sensor (TPS) Sensor 1 Circuit High Voltage.
    4. P0222: Throttle Position Sensor (TPS) Sensor 2 Circuit Low Voltage.
    5. P0223: Throttle Position Sensor (TPS) Sensor 2 Circuit High Voltage.
    6. P2135: Throttle Position Sensor (TPS) Sensor 1 And 2 Correlation.
  2. Your Chevy Malibu will run in Reduced Engine Power mode.
  3. The engine starts and runs but when you try to accelerate your Chevy Malibu, it accelerates very slowly.
  4. The engine starts and runs but the engine does not accelerate when you step on the accelerator pedal.
  5. The engine starts and runs but shuts down.

The cool thing is that the electronic throttle body can be tested with a simple multimeter. And in this tutorial I'll explain how to test the continuity of the throttle position sensor circuits within the assembly.

Electronic Throttle Body Terminal Pin Out Chart

Electronic Throttle Body Terminal Pin Out Chart. How To Test The Electronic Throttle Body (2007, 2008, 2009 3.5L (N) Chevrolet Malibu and 3.5L (N) Pontiac G6)

The engine wiring harness connector (of the electronic throttle body) has 6 wires coming out of it and it has female type terminals.

The connector on the throttle body itself has 6 male spade terminals. The illustration above is of the connector on the electronic throttle body itself.

Pin Wire Color Description
A BRN Throttle Actuator Motor Control
B YEL Throttle Actuator Motor Control
C TAN Ground
D DK GRN TPS 1 Signal
E GRY 5 Volts
F PPL TPS 2 Signal

This is probably one of the easiest electronic throttle bodies to test since it's made up of 3 easily tested components. These are:

  1. Throttle position sensor (TPS) 1.
  2. Throttle position sensor (TPS) 2.
  3. Throttle actuator motor.

Both throttle positions sensors are the potentiometer type, which means we can easily test them with a multimeter.

For more info on how the this type of electronic throttle body works, check out this article: Electronic Throttle Body Basics (2007-2009 3.5L Chevy Malibu and Pontiac G6).

TEST 1: Testing The Resistance Between Terminals C And E

How To Test The Electronic Throttle Body (2007, 2008, 2009 3.5L (N) Chevrolet Malibu and 3.5L (N) Pontiac G6)

We're gonna' test the continuity of terminals C and E. These two terminals are part of TPS 1 and TPS 2 inside the electronic throttle body.

Terminal C is the terminal that gets Ground from your 3.5L Chevy Malibu's fuel injection computer. This ground is fed to both TPS 1 and TPS 2 within the electronic throttle body.

Terminal E is the terminal that gets 5 Volts from your Malibu's fuel injection computer. These 5 Volts are fed to both TPS 1 and TPS 2 within the electronic throttle body.

What we're trying to confirm, in this test, is that continuity exists between these two terminals.

NOTE: All multimeter connections are done on the male spade terminals of the electronic throttle body itself.

youtube video You can find this test step (and all of the others) in action in this YouTube video: How To Test The Electronic Throttle Body. GM Vehicles 2006-2011.

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 the red multimeter test lead to terminal C.

  4. 4

    Connect the black multimeter test lead to terminal E.

  5. 5

    Your multimeter should read continuity.

    If continuity is present, you're gonna' see about 1.5 K Ohms.

Let's examine your test results:

CASE 1: The multimeter registered continuity between terminals C and E. This is the correct test result.

The next step is to test the continuity of terminals C and D (of TPS 1) while we manually open the throttle plate. For this test go to: TEST 2: Testing The Resistance Between Terminals D And E (TPS 1).

CASE 2: The multimeter DID NOT register continuity between terminals C and E. This lets you know that TPS 1 or TPS 2 is bad. With this test result you can conclude that the electronic throttle body is defective and needs to be replaced.