How To Test The TPS With A Multimeter (2003-2006 2.4L Honda Accord)

TEST 2: Making Sure The TPS Is Receiving 5 Volts

If you've reached this point, TEST 1 has confirmed that the throttle position sensor isn't creating a variable voltage signal as you open/close the throttle plate.

There's a good chance that it might not be receiving five Volts from the PCM. So in this test section, we're going to check that the wire I've labeled with the number 3 is delivering 5 Volts DC to the TPS.

To check for the presence of these 5 Volts in the wire, we'll do a simple multimeter voltage test.

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 the ON position but don't start the engine.

4. 4

   With the red multimeter test lead, gently probe the female terminal that connects to the yellow with blue stripe (YEL/BLU) wire of the TPS connector.
   
   I've labeled the YEL/BLU wire the the number 3 in the photo above.

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 YEL/BLU wire is feeding the TPS with 5 Volts. This is the correct test result.

Now that you have confirmed the 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 YEL/BLU wire IS NOT feeding the TPS with 5 Volts. Without these 5 Volts the TPS will not function.

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

TEST 3: Making Sure That The TPS Is Receiving Ground

Up to this point you have confirmed two things:

• The throttle position sensor is not creating a voltage signal that increases/decreases as you open/close the throttle plate (TEST 1).
• The throttle position sensor is receiving 5 Volts from the PCM (TEST 2).

For our last test, we're going to make sure that the TPS is receiving Ground from the PCM.

This Ground is delivered to the throttle position sensor via the wire that I've labeled with the number 1 in the photo above.

As in the previous tests, we're going to use our multimeter to verify the presence of Ground in the wire.

IMPORTANT: Be careful not to short the Ground wire to battery power, or you'll fry the fuel injection computer. The multimeter voltage test suggested below (to test the Ground circuit) is a safe and accurate test.

These are the test steps:

1. 1

   Place your multimeter in Volts DC mode.

2. 2

   Disconnect the TPS from its electrical connector.

3. 3

   Turn the key the ON position but don't start the engine.

4. 4

   With the black multimeter test lead, gently probe the terminal that connects to the green with yellow stripe (GRN/YEL) wire of the TPS connector.
   
   In the photo above, I've labeled the GRN/YEL wire with the number 1.

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 GRN/YEL 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 GRN/YEL 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 GRN/YEL wire between the throttle position sensor's connector and the fuel injection computer's connector.