As you're probably already aware, the throttle position sensor on your Nissan is two sensors in 1. One part of the assembly is the actual TP sensor and the other part is the idle switch.
Testing the throttle position sensor (TPS) to see if it has failed and causing a TPS diagnostic trouble code (DTC) is not hard.
In this tutorial, I'm gonna' show you how to troubleshoot the throttle position sensor (TPS) on your Nissan 3.3L Pathfinder (Frontier, XTerra or QX4), with a multimeter and in a step-by-step way.
I’m also gonna’ show you how to adjust it after removing and replacing it (you can find these instructions on the last page of this tutorial).
Here are the contents of this tutorial at a glance:
If you need to test the idle switch part of the TP sensor assembly, the following tutorial will help: How to Test the Idle Switch (Nissan 3.3L Pathfinder, Xterra, Frontier).
Since the throttle position sensor is one of several sensors that your Nissan’s fuel injection computer uses to calculate how much much fuel to inject, when it fails you’re going to see several symptoms.
As you’re probably already aware, the throttle position sensor (TPS) on your 3.3L equipped Nissan Pathfinder (Frontier, Xterra or QX4) is attached to the throttle body and its job is to measure throttle plate angle.
In layman's terms, this means that the TPS is tasked with the job of measuring how much you step on or step off the accelerator pedal as you’re driving the down the road.
This throttle plate angle information is then sent to your Nissan’s fuel injection computer as a voltage DC signal.
To give you a few more specifics:
The throttle position sensor (TPS) on your 3.3L equipped Nissan Pathfinder (Frontier, Xterra or QX4) is located on the side of the throttle body.
As you can see in photo 2 of 2 (in the image viewer) the TP sensor has 2 connectors for a total of 6 wires coming out of both. This is due to the fact that the throttle position sensor is two sensors in one. One part of the assembly is the idle switch and the other part is the throttle position sensor itself.
The bottom brown connector connects to the TP sensor part and supplies it with power, ground, and relays the throttle angle voltage signal to the PCM. The gray connector connects to the idle switch part of the assembly.
To better understand how we're gonna' test the throttle position sensor (TPS), in this tutorial, I'm going to briefly describe each wire's job and how the sensor works.
TP sensor brown connector:
REMEMBER: The throttle position sensor (TPS), at closed throttle, produces a low voltage signal of around .5 Volts DC. As the throttle plate starts to open (as you step on the accelerator pedal and accelerate the engine), this .5 Volt signal starts to increase. At wide open throttle, the TP sensor will output about 4.5 Volts DC.
With this bit of information, let's move on to the next subheading...
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