TEST 2: Making Sure The TPS Is Receiving 5 Volts
If in TEST 1, the throttle position sensor's signal did not increase/decrease, then there's a good chance that it might not be receiving power (5 Volts).
So in this test section we're going to check that the wire labeled with the letter A is providing 5 volts DC to the sensor.
The wire that connects to the terminal labeled with the letter A is the grey (GRY) wire of the TPS connector.
If the wire is supplying 5 volts DC to the TPS, then the next step is to make sure that the sensor is receiving Ground (TEST 3).
Let's get testing:
- 1
Place your multimeter in Volts DC mode.
- 2
Disconnect the TPS from its electrical connector.
- 3
Turn the key the ON position but don't start the engine.
- 4
With the red multimeter test lead (using the appropriate tool), gently probe the female terminal labeled with the letter A.
Terminal A connects to the GRY wire of the connector. - 5
Connect the black multimeter test lead to the negative (-) battery terminal.
- 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.
Now that you have confirmed that your 3.3L 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 3.3L 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 your test results 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).
In this last test section, we're going to make sure that the TPS is receiving Ground.
The wire that supplies Ground to the sensor is the wire that connects to the terminal labeled with the letter C in the photo above.
We'll do a simple multimeter voltage test to check for the presence of Ground in the black (BLK) wire.
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 Ground circuit) is a safe and accurate test.
This is what you'll need to do:
- 1
Place your multimeter in Volts DC mode.
- 2
Disconnect the TPS from its electrical connector.
- 3
Turn the key the ON position but don't start the engine.
- 4
With the black multimeter test lead (using the appropriate tool), gently probe the terminal labeled with the letter C.
Terminal C connects to the BLK wire of the connector. - 5
Connect the red multimeter test lead to the positive (+) battery terminal.
- 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 3.3L V6 Buick, Oldsmobile Tutorials
You can find a complete list of 3.3L V6 Buick (Oldsmobile) tutorials in this index:
Here's a small sample of the tutorials you'll find in the index:
- How To Test Engine Compression Test (3.3L V6 Buick, Oldsmobile).
- How To Test A Blown Head Gasket (3.3L V6 Buick, Oldsmobile).
- How To Test The MAF Sensor (3.3L V6 Buick, Oldsmobile).
- What Does A MAF Sensor Do? (3.3L V6 Buick, Oldsmobile).
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