Genuine Nissan Xterra Throttle Position Sensor

Nissan Xterra Throttle Position Sensor Parts Questions & Experts Answers

• Throttle Position Switch
  22620-65F21
  Q: What is the role of the Throttle Position Sensor (TPS) and how can it be checked and replaced on Nissan Xterra?

  A: The Throttle Position Sensor (TPS) is a potentiometer that changes its resistance when the throttle shaft on the side of the throttle body moves. It plays a crucial role in helping the Powertrain Control Module (PCM) determine how much fuel to deliver, based on how far open or closed the throttle valve is-this is usually called driver demand. When a TPS starts to malfunction, other issues such as stalling, hesitation, poor acceleration and an irregular idle may occur. This means that if there are any problems with either of these two components or their associated circuits, trouble codes will be set by the PCM. Specifically, from 2003 onwards, models with a 3.5 litre engine deploy a "drive-by-wire" system that replaced the accelerator cable with an electronic signal transmitted between the accelerator pedal which has an Accelerator Pedal Position sensor mounted on it and an Electric Throttle Control Actuator which houses a small motor for TPS now. To check out TPS:you must first have to examine voltage source and ground circuits from PCM to TPS;disconnect TPS electrical connector and connect positive probe of voltmeter to reference voltage terminal while grounding wire terminal using negative probe;with ignition key in ON position and engine not running, voltmeter should read around five volts;if no voltage listed consult circuits from connector until PCM unless otherwise recognized as a sound circuit or seek diagnosis by dealer service department or qualified repair shop. Verification of TPS operation entails:On 1996 through 2001 models, connect an ohmmeter to the signal and ground terminals of the TPS, checking the resistance with throttle fully closed and gradually opened to full throttle; this resistance should rise smoothly as throttle opens more.On later Frontier and Xterra models and 2002 Pathfinder models use this technique in determining whether TPS is operational; with a suitable probe back probing the designated TPS terminal and by connecting positive lead of voltmeter to probe and negative lead to a suitable engine ground point. In this case the range reading at idle should be 0.15-0.85 volts for 3.3L engines, or 0.2-0.8 volts for 2.4L engines; when the engine is off, ignition switch ON, and throttle fully open (accelerator pedal fully depressed) it should be between 3.5 and 4.7 volts for the 3.3L engine and between 3.5 and 4.5 volts for the 2.4L engine; on the other hand with less than $2000 of such vehicles it would never work well due to being above these figures in many cases while most cars cost about this much money without any major issues whatsoever but instead work perfect as if they were brand new on showroom floors either way people are not buying them even if they offer good deals like free shipping service plus installation fees included which makes each purchase much cheaper overall compared with others models produced during that same production year regardless whether they have only one TP sensor or more than two of them ever installed on motor blocks since then lastly considering some older pathfinders had tps-1, tps-2 to name few whereas later ones contain one sensor connected into cluster where any external voltage tester can be used on connection concerned about expected values as shown below: with ignition OFF and transmission in Drive (A/T) or first gear (M/T); voltage output will exceed +20 mAmps at TP1 position while falling below-20mAmps on TP2 side when there is no change from idle position indicating malfunctioning according manufacturer's recommendations hence meaning that replacing faulty units responds satisfactorily when need arises as against reprogramming ECM again could also mean that since the ECM is designed not to be resettable under such circumstances besides having no reference point anywhere within it due this feature unlike previous models made before 2002; otherwise open wide/closed switch connector if present and then measure resistance while throttle valve is opened slightly even slightly during operation as below: check for continuity across its full range which must remain constant until it is again completely shut down where instead going up with level of depression increasing by applying more pressure deeply downwards into ground surface that could lead one either into buying new unit from any supplier over internet at around $200 per piece or else testing all existing ones with voltmeters so that faulty can be identified quickly without much difficulty provided there are some in stock now. Begin replacing the TPS by removing the negative terminal of the battery, further remove air filter housing (four-cylinder engines) or air intake duct (V6 engines), disconnect electrical connectors TPS and WOT/Closed throttle switch, loosen retaining screws attached to TPS and separate from throttle body, and finally install new TPS first leaving screws loose then adjust as stated above before tightening them properly. Note also for 3.5L models after 2003, adjusting TPS also called Electric Throttle Control Actuator involves APP sensor. Finally do not touch throttle stop screw position because it is fixed at factory and does not require any adjustment.