How To Test The Throttle Position Sensor (3.4L V6 Buick, Oldsmobile)

TEST 2: Making Sure The TPS Is Receiving 5 Volts

If you've reached this point, then your TEST 1 results have confirmed that the TPS voltage signal is not increasing/decreasing as you open/close the throttle plate.

There's a good chance that this is the result of the throttle position sensor not receiving 5 Volts from the fuel injection computer.

So, in this test section we're going to test the wire labeled with the letter A and see if it's supplying 5 Volts with the key on but engine off.

The wire that supplies 5 Volts to the TPS, and which is labeled with the letter A in the photo above, is the gray (GRY) wire of the TPS 3-wire connector.

Let's get testing:

1. 1

   Place your multimeter in Volts DC mode.

2. 2

   Disconnect the TPS from its electrical connector.

3. 3

   Turn the key on but don't start the engine.

4. 4

   With the red multimeter test lead (using the appropriate tool), gently probe the female terminal that connects to the wire labeled with the letter A.

5. 5

   Connect the black multimeter test lead to the negative (-) battery terminal.

6. 6

   Your multimeter should read 4.5 to 5 Volts DC.

Let's analyze your test results:

CASE 1: The GRY wire is feeding the TPS with 5 Volts. This is the correct test result and it confirms that the TPS is receiving power.

Now that you have confirmed that your 3.4L V6 Buick (Oldsmobile)'s TPS is getting 5 Volts, the next step is to make sure it's getting Ground. Go to: TEST 3: Making Sure That The TPS Is Receiving Ground.

CASE 2: The GRY wire IS NOT feeding the TPS with 5 Volts. Without these 5 Volts the TPS, on your 3.4L V6 Buick (Oldsmobile), will not function.

These missing 5 Volts are usually the result of an open-circuit problem in the GRY wire between the TPS sensor's connector and the fuel injection computer's connector.

TEST 3: Making Sure That The TPS Is Receiving Ground

So far the previous two tests have confirmed:

• That the TPS signal voltage is not increasing/decreasing as you open/close the throttle plate (TEST 1).
• That the TPS is receiving 5 Volts DC (TEST 2).

For our last test we're going to make sure that the wire labeled with the letter B is supplying Ground to the throttle position sensor.

To check for the presence of Ground in this wire, we're going to do a simple multimeter voltage test.

IMPORTANT: Be careful and don't short the Ground wire to battery power or you'll fry the fuel injection computer. The multimeter voltage test suggested below (for testing the presence of Ground in the wire) is a safe and accurate test.

This is what you'll need to do:

1. 1

   Place your multimeter in Volts DC mode.

2. 2

   Disconnect the TPS from its electrical connector.

3. 3

   Turn the key on but don't start the engine.

4. 4

   With the black multimeter test lead (using the appropriate tool), gently probe the terminal that connects to the wire labeled with the letter B.

5. 5

   Connect the red multimeter test lead to the positive (+) battery terminal.

6. 6

   Your multimeter should read 10 to 12 Volts DC.

Let's analyze your test results:

CASE 1: The BLK wire is feeding Ground to the TPS. This is the correct test result.

You can correctly conclude that the TPS is defective if you have:

• Confirmed that the TPS voltage signal does not increase/decrease as you opened/closed the throttle plate (TEST 1).
• Confirmed that the TPS is getting 5 Volts (TEST 2).
• Confirmed, in this test section, that the TPS is getting Ground.

CASE 2: The BLK wire IS NOT feeding Ground to the TPS. Without Ground the TPS will not function.

This missing Ground is usually caused by an open-circuit problem in the BLK wire between the throttle position sensor's connector and the fuel injection computer's connector.

More 3.4L V6 Buick, Oldsmobile Tutorials

You can find a complete list of 3.4L V6 Buick (Oldsmobile) tutorials in this index:

• GM 3.4L Index Of Articles.

Here's a small sample of the tutorials you'll find in the index:

• How To Test Engine Compression Test (3.4L V6 Buick, Oldsmobile).
• How To Test A Blown Head Gasket (3.4L V6 Buick, Oldsmobile).
• What Does The CKP Sensor Do? (3.4L V6 Buick, Oldsmobile).
• What Do The Spark Plugs Do? (3.4L V6 Buick, Oldsmobile).