TEST 2: TPS 1 Resistance Test (Part 2 Of 2)
In this test section, we're gonna' test the resistance between terminal A and terminal C while we manually open and close the throttle plate.
If TPS 1 is OK, then its resistance value should increase as we open the throttle plate and decrease when we close it.
If TPS 1 is defective, the resistance value will have gaps in its reading or will stay stuck in one value as you open and close the throttle plate.
These are the test steps:
- 1
Disconnect the throttle body from its electrical connector.
- 2
Place your multimeter in Ohms mode.
- 3
Connect one multimeter test lead to terminal A and the other to terminal C.
NOTE: All connection are done on the male terminals of the connector of the throttle body itself.
At this point I usually get a reading of about 3.2 K Ohms from a good TPS 1. - 4
Slowly open the throttle plate by hand till it reaches its wide open throttle (WOT) position.
The resistance value should increase smoothly and without any gaps as you open the throttle plate. At this point I usually get a reading of about 5 K Ohms from a good TPS 1.
If TPS 1 is defective, you'll see gaps in the resistance reading or the Ohms reading will stay stuck in one value. - 5
Slowly close the throttle plate by hand and push the throttle plate so that it completely closes.
The resistance value should decrease smoothly and without any gaps as you close the throttle plate.
At this point (the throttle plate pushed down and completely closed) I generally get a reading of about 2.3 K Ohms from a good TPS 1.
Let's examine your test results:
CASE 1: The resistance increased/decreased without any gaps. This is the correct test result.
If TPS 1 passed TEST 1 and TEST 2, then you can conclude that it's not defective. Your next step is to test TPS 2. Go to: TEST 3: TPS 2 Resistance Test (Part 1 Of 2).
CASE 2: The multimeter DID NOT register the indicated resistance values. This lets you know that TPS 1 is bad. You'll need to replace the throttle actuator assembly.
TEST 3: TPS 2 Resistance Test (Part 1 Of 2)
If you've reached this point, then TPS 1 has passed TEST 1 and TEST 2 with flying colors. Now we're gonna' focus on testing TPS 2.
We're gonna' test the resistance between terminal B and terminal H of the throttle body's connector.
Terminal B is the terminal that receives Ground from your 2.2L Chevy Cobalt's fuel injection computer.
Terminal H is the one that gets 5 Volts from your 2.2L Chevy Cobalt's fuel injection computer.
NOTE: All tests are done on the connector on the throttle body itself. This connector has male spade terminals.
These are the test steps:
- 1
Disconnect the throttle body from its electrical connector.
- 2
Place your multimeter in Ohms mode.
- 3
Connect the red multimeter test lead to terminal B.
- 4
Connect the black multimeter test lead to terminal H.
- 5
Your multimeter should read continuity.
At this point I have gotten around 2.4 K Ohms from a good TPS 2.
Let's examine your test results:
CASE 1: The multimeter registered continuity between terminals B and H. This is the correct test result.
The next step is to test TPS 2 while you open and close the throttle plate. For this test go to: TEST 4: TPS 2 Resistance Test (Part 2 Of 2).
CASE 2: The multimeter DID NOT register continuity between terminals B and H. This lets you know that TPS 2 is bad. You'll need to replace the throttle actuator assembly.
