TEST 2: Making Sure The TPS Is Receiving 5 Volts
The throttle position sensor on your 2.2L Cavalier (Beretta, Corsica, Sunfire) needs power and Ground to function.
In this second test section, you'll check the gray (GRY) wire to see if it's providing 5 Volts (in TEST 3, you'll check that the black wire is delivering Ground).
I've labeled the GRY wire with the letter A in the photo above.
These are the test steps:
- 1
Select Volts DC mode on your multimeter.
- 2
Disconnect the TP sensor from its connector.
- 3
Probe the brown with white stripe (GRY) wire with the red multimeter test lead and an appropriate tool.
The GRY wire is labeled with the letter A in the photo above.
NOTE: Be careful not to damage the female terminal. - 4
Connect the black multimeter test lead to the negative (-) battery terminal.
- 5
When everything is set up, have a helper rotate the key to its ON position but don't start the engine.
- 6
The multimeter should report 4.5 to. Volts DC.
Let's interpret your test results:
CASE 1: The GRY wire is delivering 4.5 to 5 Volts. This is the correct test result and confirms the TPS is getting power.
Your next and last step is to see if the TPS is getting Ground. Go to: TEST 3: Making Sure The TPS Is Receiving Ground.
CASE 2: The GRY wire IS NOT delivering 4.5 to 5 Volts. Without power the TPS will not function.
Although it's beyond the scope of this tutorial, your next step is to find out why this voltage is missing and restore it.
TEST 3: Making Sure The TPS Is Receiving Ground
So far, the previous two tests have confirmed:
- The TPS signal voltage does not increase/decrease as you open/close the throttle plate (TEST 1).
- The gray wire is delivering 4.5 to 5 Volts (TEST 2).
In this last test section, you'll check that the black (BLK) wire delivers Ground to the throttle position sensor.
I've labeled the BLK wire with the letter B in the photo above.
The quickest and easiest way to confirm the presence of Ground (in the BLK wire) is with a multimeter voltage test.
Let's get started:
- 1
Select Volts DC mode on your multimeter.
- 2
Disconnect the TP sensor from its connector.
- 3
Probe the black (BLK) wire with the black multimeter test lead and an appropriate tool.
The BLK wire is labeled with the letter B in the photo above.
NOTE: Be careful not to damage the female terminal. - 4
Connect the red multimeter test lead to the positive (+) battery terminal.
- 5
When everything is set up, have a helper rotate the key to its ON position but don't start the engine.
- 6
The multimeter should display 10 to 12 Volts DC.
Let's interpret your test results:
CASE 1: Your multimeter registered 10 to 12 Volts. This is the correct test result and confirms the TPS is getting Ground.
You can conclude the TPS is bad if you have:
- Confirmed the TPS signal voltage does not increase/decrease as you open/close the throttle plate (TEST 1).
- Confirmed the gray wire is delivering 4.5 to 5 Volts (TEST 2).
- Confirmed the black wire is delivering Ground to the sensor (this test section).
CASE 2: Your multimeter DID NOT register 10 to 12 Volts. Without Ground the TPS will not function.
Although it's beyond the scope of this tutorial, your next step is to find out why Ground is missing and restore it.
More 2.2L Beretta, Cavalier, Corsica, And Sunfire Diagnostic Tutorials
If this tutorial was helpful, be sure and take a look at all of the 2.2L Beretta, Cavalier, Corsica, And Sunfire diagnostic tutorials in this index:
Here's a sample of the tutorials you'll find there:
- How To Test The Thermostat (1992-1997 2.2L Beretta, Cavalier, Corsica, Sunfire).
- How To Test The Fuel Pump (1992-1997 2.2L Beretta, Cavalier, Corsica, Sunfire).
- How To Test The Front Oxygen Sensor With A Multimeter (2.2L GM).
- How To Test The GM 2.2L Ignition Coil Pack.
If this info saved the day, buy me a beer!
