The throttle position sensor (TPS) on your 2.2L Honda Accord (Odyssey) can be accurately tested with a multimeter -no scan tool required!
In this tutorial, I'll show you how so that you can find out if it's bad (or not) and in the process troubleshoot the following diagnostic OBD II trouble codes:
- P0122: Throttle Position Sensor Circuit Low Input.
- P0123: Throttle Position Sensor Circuit High Input.
- P1121: Throttle Position Sensor Signal Lower Than Expected.
- P1122: Throttle Position Sensor Signal Higher Than Expected.
Contents of this tutorial:
APPLIES TO: This tutorial applies to the following vehicles:
- 2.2L Honda Accord (DX, EX, LX): 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997.
- 2.2L Honda Odyssey: 1995, 1996, 1997.
Basics Of The Throttle Position Sensor (TPS)
As you already know, the throttle plate is connected to the accelerator pedal via the accelerator cable. So, when you step on or off the accelerator pedal, the throttle plate opens or closes.
It's the job of the throttle position sensor (TPS) to measure the amount the throttle plate opens and report this information to your 2.2L Honda Accord or Odyssey's fuel injection computer.
The TPS, on your Honda Accord or Odyssey, is a 3-wire sensor. Each wire has a specific job to do and in the following table, you'll find a brief description of each:
| 1990-1993 TPS Circuits | ||
|---|---|---|
| Pin | Wire Color | Description |
| 1 | GRN/WHT | Ground |
| 2 | RED/BLK | Throttle Position Signal |
| 3 | YEL/WHT | Power (5 Volts DC) |
| 1994-1997 TPS Circuits | ||
|---|---|---|
| Pin | Wire Color | Description |
| 1 | GRN/BLK | Ground |
| 2 | RED/BLK | Throttle Position Signal |
| 3 | YEL/BLU | Power (5 Volts DC) |
Where To Buy The TPS And Save
The TPS is not an expensive engine management component. The following link will help you comparison shop for the TPS:
Not sure if the throttle position sensor listed above fits your particular 2.2L Honda Accord (Odyssey)? Don't worry, once you get to the site they are going to ask you the specifics of your vehicle to make sure it fits. If it doesn't fit, they'll find you the right one.
TEST 1: Checking The Throttle Position Sensor (TPS) Signal
The first thing that we're gonna' do is to check the TPS signal.
To be a bit more specific, we're gonna' make sure that the TPS signal voltage increases/decreases as we open/close the throttle plate.
The wire that carries the TPS signal, and the one we're gonna' connect a multimeter to, is the wire labeled with the number 2 in the photo above.
On the 1990-1997 2.2L Honda Accord and 1995-1997 2.2L Honda Odyssey, this is the red with black stripe (RED/BLK) wire of the sensor's 3-wire connector.
IMPORTANT: This is an on car test of the sensor and the throttle position sensor must remain connected to its harness connector.
These are the steps:
- 1
Place your multimeter in Volts DC mode and connect the red test lead to the RED/BLK wire of the TP sensor harness connector.
NOTE: The TP sensor connector needs to be connected to the TPS, so you'll need to either back-probe the connector or use a wire piercing probe to get to the signal inside the wire (to see what a wire piercing probe looks like: Wire Piercing Probe Tool). - 2
Ground the black multimeter test lead directly on the battery negative (-) post.
- 3
Manually rotate the throttle.
You'll get the best results by opening and closing the throttle directly on the throttle body instead of stepping on the accelerator pedal. - 4
The multimeter should show an increasing voltage as you (or your helper) open up the throttle.
You'll get the best results by opening and closing the throttle directly on the throttle body instead of stepping on the accelerator pedal. - 5
The multimeter should show a decreasing voltage as you begin to close the throttle.
- 6
Using a screwdriver's handle, gently tap the TP sensor as you open and close the throttle and observer the multimeter.
The purpose (of tapping the TP sensor with the screwdriver's handle) is to see if the TP sensor shows gap's in the voltage signal. Why? Because a good TP sensor will show a continuous increasing or decreasing voltage signal even while getting tapped by the screw-driver's handle.
Let's take a look at your test results:
CASE 1: The TPS signal voltage increased/decreased smoothly and without gaps. This is the correct and expected TPS test result. This result tells you that the TPS is working correctly.
You can also conclude that the throttle position sensor is getting power and Ground.
CASE 2: The TPS signal voltage did not increase or decrease. This test result usually means that they TP sensor is defective but not always.
The next step, before we conclude that the TP sensor is bad, is to make sure that it's getting power and Ground. For these two tests, go to: TEST 2: Making Sure The TPS Is Getting 5 Volts.
CASE 3: The TPS signal voltage showed gaps in its voltage output as you tapped the sensor with the screwdriver. If the voltage signal (on your multimeter) reacted to the screwdriver tapping on the TP sensor, then this is a sure sign that the TPS is defective and needs to be replaced.
