How To Test The Electronic Throttle Body (2004-2006 2.8L Chevrolet Colorado, GMC Canyon)

This tutorial will help you test the electronic throttle body on the 2004-2006 2.8L Chevrolet Colorado and GMC Canyon.

You'll quickly determine if the electronic throttle body is good or bad with your test results.

You can find this tutorial in Spanish here: Cómo Probar El Cuerpo Del Acelerador Electrónico (2004-2006 2.8L Chevrolet Colorado, GMC Canyon) (at: autotecnico-online.com).

APPLIES TO: This tutorial applies to the following vehicles:

• 2.8L Chevrolet Colorado: 2004, 2005, 2006.
• 2.8L GMC Canyon: 2004, 2005, 2006.

WIRING DIAGRAM: You can find the electronic throttle body circuits wiring diagram here:

• TAC System Wiring Diagram (2004-2006 2.8L Chevrolet Colorado, GMC Canyon).

Symptoms Of A Bad Electronic Throttle Body

The electronic throttle body on your 2004-2006 2.8L Chevrolet Colorado (GMC Canyon) is a part of the engine management system. When it fails, you're gonna see one or more of the following symptoms:

• The check light engine light will be lit up by one of the following trouble codes:
  • P0121: Throttle Position Sensor (TPS) Sensor 1 Performance.
  • P0122: Throttle Position Sensor (TPS) Sensor 1 Circuit Low Voltage.
  • P0123: Throttle Position Sensor (TPS) Sensor 1 Circuit High Voltage.
  • P0222: Throttle Position Sensor (TPS) Sensor 2 Circuit Low Voltage.
  • P0223: Throttle Position Sensor (TPS) Sensor 2 Circuit High Voltage.
  • P2135: Throttle Position Sensor (TPS) Sensor 1 And 2 Correlation.
• Your 2.8L Chevrolet Colorado (GMC Canyon) will run in Reduced Engine Power mode.
• The engine starts and runs, but it revs up very slowly when you try to accelerate your Chevy Colorado (GMC Canyon) from a stop or down the road.
• The engine starts and runs, but the engine does not accelerate when you step on the accelerator pedal.
• The engine starts and runs but shuts down.

Electronic Throttle Body Terminal Pin Out Chart

Three electrical components make up the electronic throttle body. These are:

• Throttle position sensor (TPS) 1.
• Throttle position sensor (TPS) 2.
• The throttle actuator motor.

Because of these three components, the throttle body's electrical connector has a total of 8 wires coming out of it. Here's a brief description of each:

Pin	Wire Color	Description
A	Dark green (DK GRN)	TPS 1 Signal
B	Light blue with black stripe (LT BLU/BLK)	5 Volts (TPS 2)
C	Black (BLK)	Ground (TPS 1)
D	Purple (PPL)	TPS 2 Signal
E	Yellow (YEL)	Throttle Actuator Motor Control
F	Brown (BRN)	Throttle Actuator Motor Control
G	Grey (GRY)	5 Volts (TPS 1)
H	Black with white stripe (BLK/WHT)	Ground (TPS 2)

The connector on the throttle body itself has male spade terminals. The terminals on the electrical connector are female terminals.

NOTE: You'll perform all of the tests in this tutorial on the connector of the throttle body itself, and this connector has male spade terminals.

Where To Buy The Electronic Throttle Body And Save

The following links will help you comparison shop for the electronic throttle body for 2004, 2005, and 2006 2.8L Chevrolet Colorado and GMC Canyon.

The links are to known automotive brands (GM Genuine/AC Delco and Dorman)! Avoid a cheap knock-off that will end up causing you more headaches down the road.

Not sure if the electronic throttle body will fit your particular GM vehicle? Don't worry. Once you get to the site, they'll make sure it fits. If it doesn't, they'll find you the right one.

TEST 1: TPS 1 Resistance Test (Part 1 Of 2)

You'll first test for continuity across male spade terminals C and G of the throttle body's connector (these two terminals belong to TPS 1).

If your multimeter does not report an open-circuit or a short-circuit problem, you can move on to TEST 2.

NOTE: You'll make all multimeter connections on the male spade terminals of the electronic throttle body itself.

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 G.

5. 5

   Your multimeter should read continuity.
   
   To be a bit more specific, you should see a value somewhere between 2K to 4K Ohms.

Let's examine your test results:

CASE 1: The multimeter registered continuity between terminals C and G (a value somewhere between 2K to 4K Ohms). This is the correct test result.

The next test is to check TPS 1 while you manually open and close the throttle plate. For this test, go to: TEST 2: TPS 1 Resistance Test (Part 2 Of 2).

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

With this test result, you can conclude that the electronic throttle body is defective and needs replacement.

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

With this test result, you can conclude that the electronic throttle body is defective and needs replacement.