The Nissan 240SX Throttle Position Sensor is also found in other Nissan vehicles that share the same 2.4-liter KA24DE engine. DTC OBDII trouble code P0120 has to do with the failure of your throttle position sensor to provide data to your ECU. When this DTC trouble code is triggered, a Check engine light (CEL) will be illuminated on your 240SX instrument panel.
This TPS diagnostic trouble code (DTC) is then stored in the PCM’s memory as the P0120: Throttle Position Sensor Circuit.
Symptoms of the DTC P0120 trouble code are :
- Inefficient gas mileage
- Car smokes from tailpipe
- Car hesitates and sputters
- Car backfires or bogs and refuses to idle
How To Service your KA24DE Throttle Position Sensor
The part number for your replacement throttle position sensor is 22620-31U15, and as we stated earlier it can be found in many different Nissan vehicles.
There are two different sets of plugs on your throttle position sensor, and we’ll be teeing and testing the first bank of three pin connectors. This circled plug has a pigtail that leads off the throttle body and ends with a weatherproof three pin termination.
To gain access to your 240SX throttle position sensor, you must unplug your MAF, AIT, and your distributor before removing your intake tube to expose the throttle body.
Our How To Service a 240SX Throttle Position Sensor Guide will require you to put the key to the “ON” position before testing. First locate your throttle position sensor and pigtails that lead from it.
Now once you’ve located the throttle position sensor and the pigtailed wiring loom, pull the loom off and inspect the wiring. The plug you are looking for is the black plug, not the brown one.
You will be testing the voltage range from the Throttle Position Sensor signal wire, which is indicated below in our 240sx throttle position sensor pinout.
Using your multimeter, you will be testing all three of the wires in the three prong wiring connector to your 240SX throttle position sensor. To test this however, you will need all of the throttle related connectors plugged in and your ignition key turned to the “ON” position.
Using your multimeter or similar measuring device, test the middle wire on your TPS sensor connector. Now ground the multimeter to see what voltage is being sent from your throttle body position sensor. You should see a base voltage of .2 to .5 depending on your application.
You can also test using the back of this harness and teeing into the rear of the metal clips on the wires themselves. Use your other hand, or have a friend get into the car and depress the throttle. With your multimeter connected to the middle wire, you should now be able to see a solid and granular range of voltage.
If your voltage range has blank spots or there seems to be missing values from your voltage range, stop now and replace your throttle position sensor.
If your 240SX TPS sensor does respond and the throttle body angle is correctly conveyed to your Nissan ECU. Then more than likely your problem is intermittent. Use a healthy wallop of dielectric grease to help your throttle position sensor make a firm and solid connection.
If your 240SX TPS sensor does not respond, or has problems with the throttle body sensor voltage ranges, you must test the power and ground to ensure that the sensor is indeed your problem.
Test your 240SX throttle position sensor for switched power and a solid ground, and you have now completed our How To Service a 240SX Throttle Position Sensor writeup!