TEST 2: TPS 1 Resistance Test (Part 2 Of 2)
In this section, you'll test the resistance between male spade terminals A and G while manually opening and closing the throttle plate.
As you open the throttle plate, the resistance value your multimeter reports should increase.
As you close the throttle plate, the resistance value your multimeter reports should decrease.
If there's a problem between these two male spade terminals, you'll see:
- The resistance value stay stuck in one value as you open/close the throttle plate.
- Gaps in the multimeter Ohms reading as you open/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.
NOTE: All connection are done on the male terminals of the connector of the throttle body itself. - 4
Connect the other multimeter test lead to terminal G.
At this point I usually get a reading between 2K to 3K Ohms from a good TPS 1. - 5
Slowly open the throttle plate by hand till it reaches its wide-open throttle (WOT) position.
- 6
The resistance value should increase as you open the throttle plate.
At WOT I usually see a reading between 4K to 5K Ohms from a good TPS 1. - 7
Slowly close the throttle plate to its closed position.
- 8
The resistance value should decrease as you close the throttle plate.
- 9
Gently push down and completely close the throttle plate.
- 10
The resistance value should continue to decrease as you completely close the throttle plate.
At this point (the throttle plate pushed down and completely closed) I generally get a reading between 1K to 2K 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 and lets you know TPS 1 is OK (not defective).
The next test is a resistance test between terminals H and B of TPS 2. Go to: TEST 3: TPS 2 Resistance Test (Part 1 Of 2).
CASE 2: The resistance DID NOT increase/decrease. This lets you know TPS 1 is bad. You'll need to replace the throttle body unit.
TEST 3: TPS 2 Resistance Test (Part 1 Of 2)
Now that you've confirmed TPS 1 is OK, the next step is testing the circuits of TPS 2.
You'll start off troubleshooting TPS 2 by testing the continuity between male terminals B and H (of the electronic throttle body itself).
If all is good between these two terminals, your multimeter will report continuity.
If there's a problem in the circuit, your multimeter will report:
- A short-circuit problem (an Ohms reading less than 1 Ohm).
- An open-circuit problem (a reading of OL -Open Loop).
If your multimeter registers continuity in the circuit, you'll move on to TEST 4.
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 2K 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 opening and closing the throttle plate. For this test go to: TEST 4: TPS 2 Resistance Test (Part 2 Of 2).
CASE 2: The multimeter registered 0 Ohms between terminals B and H (or a value very close to it). This test result indicates a short-circuit problem between terminals B and H.
With this test result you can conclude the electronic throttle body is defective and needs replacement.
CASE 3: The multimeter reports no continuity between terminals B and H (the letters OL are displayed). This test result indicates an open-circuit problem between terminals B and H.
With this test result you can conclude the electronic throttle body is defective and needs replacement.
