P0220 TP Sensor B Circuit Malfunction (With TAC Electronic Throttle Body)

TEST 5: Throttle Position (TP) Sensor 2 Resistance Test

You've reached the final TP Sensor 2 (B) test of this tutorial. In this test, I'm gonna' ask you to do a resistance test of TP Sensor 2 while you open and close its Throttle Plate.

This final TP Sensor 2 test will let you know conclusively if TP Sensor 2 is bad or not, but all this depends on the type of multimeter you're using.

IMPORTANT: For the TP Sensor 2 (B) resistance test to be accurate, you NEED to use an analog multimeter. If you don't have one, you can use a digital multimeter that has a bar graph in Ohms mode. This is important, because a digital multimeter that does not have a bar graph will not respond fast enough to the changes in throttle plate angle and will show gaps in the values (these gaps may lead you to believe the sensor is bad when it isn't).

OK, to get this pie baked, this is what you need to do:

STEP 1:

1. Disconnect the Electronic Throttle Body's electrical connector.
   • NOTE: You can do this test with the throttle body off of the vehicle (this is what I do, since it's a whole lot easier to test it this way) or you can test it while it's on the vehicle.
2. Locate pin E and pin F on the throttle body (see photo above).
   • Connect the multimeter lead to these two pins using crocodile tip connectors (you can buy these at Radio Shack, see photo of crocodile tip).
3. Measure the resistance of these 2 pins with your multimeter in Ohms mode.
   • This test is done with the throttle plate at its rest position (closed).
   • Do not apply any more pressure on the throttle plate to completely close it.
4. Your multimeter should read about 4.0 K ohms.

STEP 2:

5. Now, slowly open the throttle plate by hand till it reaches its maximum wide open throttle (WOT) position.
6. As you open the throttle plate, the Ohms readings should decrease.
   • If you're using an analog multimeter, the multimeter's needle should smoothly move up without any big jerky jumps.
   • If you're using a digital multimeter with a bar graph, the bar graph should indicate a smooth increase in bars.
7. At wide open throttle, your multimeter should register about 1.2 to 1.4 K Ohms.

STEP 3:

8. Now, slowly close the throttle plate till it reaches its closed throttle position.
9. As you close the throttle plate, the Ohms readings should increase.
   • If you're using an analog multimeter, the multimeter's needle should smoothly move down without any big jerky jumps.
   • If you're using a digital multimeter with a bar graph, the bar graph should indicate a smooth decrease in bars.
10. Repeat steps 5 through 9 a couple of times, just to make sure you get the same results each time.

Let's interpret your test results:

CASE 1: The multimeter registered a smooth increase and decrease of Ohms values... more to the point, you saw the multimeter's needle smoothly move up or down as you opened and closed the throttle plate. This is the good and normal test result and let's you know that Throttle Position (TP) Sensor 2 is OK and not the cause of the issue (P0220 trouble code).

Now, since you still have a P0220 DTC lighting up the check engine light, it's starting to sound like the TAC Module is bad. I'm not suggesting replacing it since testing it is beyond the scope of this tutorial. What I'm suggesting is that your troubleshooting needs to focus on the TAC Module.

CASE 2: The multimeter DID NOT register a smooth increase or decrease of Ohms values ... more to the point, the values got stuck at a certain point, or you saw gaps, or values that did not correspond with opening or closing the throttle plate.

This tells you that Throttle Position (TP) Sensor 2 is bad and is the root cause of the P0220: TP Sensor 2 Circuit Malfunction trouble code. Since TP Sensor 2 is part of the Electronic Throttle Body, you'll need to replace the entire thing.

NOTE: This test result is true ONLY if you are using an analog multimeter or a digital multimeter with a bar graph. Why? Because it's normal for a digital multimeter without a bar graph to show gaps in the Ohm's numbers it's displaying (the bar graph won't show any gaps, since it's able to respond fast enough).