Short answer
Confirm the fault with a sweep test, disconnect the battery, unplug the sensor, remove its two screws, and fit the replacement so its drive engages the throttle shaft. Plug it in, check the closed-throttle reading against your service manual, clear codes, and run the idle or throttle relearn your vehicle needs. On electronic throttles the sensor is usually built into the throttle body, so the job becomes a throttle body swap.
Before you buy: is the sensor separate?
Look at the throttle body. If a cable from the gas pedal turns it, the TPS is normally its own part. If there is no cable and a motor housing on the side, it is an electronic throttle. OBD-Codes.com describes those throttle bodies as having two embedded position sensors, so you usually replace the whole body. Some electronic throttle bodies do have a sensor-only replacement: SMP sells direct-fit sensors for some applications that let you replace only the sensor. TPS vs throttle body goes deeper.
How to replace a TPS sensor on a cable throttle
Confirm the diagnosis
Do the sweep test and check the reference, ground and wiring first. Code references list wiring and connectors among the most common causes, and a replacement sensor will not fix a broken wire.
Let the engine cool and disconnect the battery
Disconnect the negative battery cable. Note that this can reset idle settings and stored codes.
Unplug the sensor
Press the connector tab and pull the plug straight off. Look for corrosion, water and bent pins while it is apart.
Mark and remove the old sensor
If the sensor has slotted holes, mark its position on the throttle body first. Remove the two screws and pull the sensor straight off the shaft.
Compare the parts
Check that the replacement matches: connector shape, pin count, drive shape, and rotation direction. Match the number on the old part or your VIN.
Fit the replacement
Slide it on so the drive engages the throttle shaft and the sensor sits flat with no gap. Do not force it. Fit the screws snugly; do not overtighten into the aluminum.
Check the closed-throttle reading
Reconnect the plug and battery, key on, and read the signal with a meter or scan tool. Adjustable sensors are set to the factory voltage in your service manual; fixed sensors should already read in range.
Clear codes and relearn
Clear the codes and run the idle or throttle relearn your service manual describes, then test drive and rescan.
Relearn guidance from Jerry’s TPS replacement guide; wiring causes from OBD-Codes.com.
Where people go wrong
- Sensor not seated. OBD-Codes.com lists "TPS not mounted securely" as a cause of P0122 and P0123, and a reader tip there notes the code can follow a sensor that was not rotated correctly as it went on.
- Skipping the connector. A green, corroded plug will make the replacement fail too. Clean it with contact cleaner and use a little dielectric grease on the seal.
- Wrong part. Similar-looking sensors can rotate the opposite way or use a different drive. Match by VIN or part number.
- No relearn. Idle hunting or sitting high after the swap is the classic sign.
Electronic throttle body replacement, briefly
On drive by wire engines, replacing the throttle body usually means removing the intake tube, a connector, a few mounting bolts and a gasket, followed by a relearn that some vehicles can only do with a scan tool. Do not push the throttle plate open by hand on these units. Check prices first: a throttle body costs far more than a sensor, as the cost guide shows.
Questions people ask
Where is the TPS sensor located?
On the side of the throttle body, on the end of the throttle shaft opposite the cable or linkage. Follow the intake tube from the air filter to the engine; the throttle body is where it meets the intake manifold. On electronic throttles the sensor sits inside the throttle body housing.
How do I reset a TPS sensor after replacing it?
It depends on the vehicle. Jerry notes many cars need a relearn after replacement; some do it with a key-on and idle routine, others need a scan tool. Clearing codes alone is not always enough. The exact routine is in your service manual.
Do I need to disconnect the battery?
It is the safe habit before unplugging sensors. Be aware it can also reset idle and radio settings, and on many vehicles it triggers the same relearn you need anyway.
Why is my idle high after replacing the TPS?
Usually because the computer has not relearned closed throttle, the sensor is not seated on the shaft, or an adjustable sensor is set wrong. Jerry notes that if idle hunts or stays high after replacement with no faults present, the relearn is necessary.
Sources
Last reviewed 2026-10-12. General guidance only: specs, procedures and fitment vary by vehicle, so confirm in your service manual and on the listing before you buy or wrench.