How To Test The Throttle Position Sensor (Ford 5.0L, 5.8L)

Accurately testing the throttle position sensor (TPS) on your Ford five.0L or five.8L pickup, van or SUV is not difficult to do.

In this 'How To' tutorial, I'll show you lot how to exam the TPS with a multimeter and find out if it's really bad or not.

This is an on-motorcar test of the throttle position sensor. You lot'll find that the photos show the TPS out of the car, but this is only to make it easier to explain the test.

En Español Y'all can find this tutorial in Spanish here: Cómo Probar El Sensor TPS (Ford v.0L, 5.8L) (at: autotecnico-online.com).

Symptoms Of A Bad Throttle Position Sensor

The ane thing that you tin definitely count on, when the TPS fails, is the cheque engine light shining overnice and bright to permit y'all know that there's a diagnostic trouble code stored in the fuel injection computer. Here are some specific symptoms y'all'll see:

  1. TPS diagnostic problem codes (DTCs) stored in the vehicle'south reckoner's memory.
    • Lawmaking 23: Throttle Position (TP) Excursion Operation Trouble.
    • Code 53: Throttle Position (TP) Circuit High Input.
    • Lawmaking 63: Throttle Position (TP) Circuit Depression Input.
    • Lawmaking 121: Throttle Position (TP) Excursion Performance Problem.
    • Code 122: Throttle Position (TP) Circuit Low Input.
    • Lawmaking 123: Throttle Position (TP) Circuit Loftier Input.
  2. Really bad gas mileage.
  3. No ability as you accelerate the vehicle.
  4. Hesitation when yous step on the accelerator pedal.

There are times when the ECM (Electronic Control Module = Fuel Injection Calculator) will recollect the TPS has failed when it hasn't. This usually happens when the ECM spits out several diagnostic problem codes at once and so what volition salve you time, money and the frustration of replacing skillful parts, is to test the throttle position sensor.

What Tools Are Needed To Test The TPS?

The most important tool you'll demand is a multimeter. The multimeter tin be an analog or digital one (don't have a digital multimeter? Demand to purchase 1? Click here to see my recommendations: Buying A Digital Multimeter For Automotive Diagnostic Testing).

You'll also need:

  1. A helper.
  2. Wire piercing probes
    • Since the TPS has to be tested in action (and with the key in the ON position), you'll demand to pierce the wires with something to get to the signal inside the wire.
    • To meet what a wire piercing probe looks like, click here: Wire Piercing Probe.

A generic scan tool that can read OBD I diagnostic problem codes does come in handy, but the scan tool won't aid you lot examination the TPS and therefore you lot won't demand information technology to use the test info in this tutorial (the exam in this tutorial volition help you exam the TPS without a scan tool).

Circuit Descriptions Of The Throttle Position Sensor

Circuit Descriptions Of The Throttle Position Sensor. How To Test The Throttle Position Sensor (Ford 5.0L, 5.8L)

Beneath are the chore descriptions of the three wires that stick out of the TPS:

  1. Excursion labeled 1:
    • five Volts from PCM.
    • This wire is Red in colour.
  2. Circuit labeled 2:
    • Throttle Position (TP) Betoken Circuit.
    • This wire is Black in colour.
  3. Circuit labeled 3:
    • Sensor Footing Circuit.
    • This wire is Greenish in color.

You'll need to keep i very important thing in mind and that's that these three circuits go direct to the ECM. And so yous need to be careful not to short these wires to power (12 Volts) or you will fry the fuel injection computer.

How Does The Throttle Position Sensor Piece of work?

The TP sensor'southward job is to inform the ECM how much the throttle plate is opening or closing. Information technology's able to do this considering it'south mounted on the throttle body and directly linked to the throttle plate shaft. So when the throttle plate shaft rotates, a wiper within the TPS as well moves (along a curved resistor) and is able to ship a variable voltage signal to the ECM.

OK, in a nutshell, when yous crank and get-go your Ford vehicle:

  1. The throttle position sensor gets 5 Volts and Ground from the ECM.
  2. As the engine in your pickup or van idles (and the throttle plate is closed), the throttle position sensor sends the ECM a voltage signal of about 0.nine to ane Volts.
  3. In one case you step on the accelerator pedal, the throttle plate opens and since the TPS is continued to the throttle, information technology starts to measure how much information technology opens.
  4. When the throttle plate opens, the voltage increases. When the throttle plate closes, the voltage decreases.
  5. The ECM is then fed this changing voltage.
  6. Once the PCM gets this voltage, information technology does its little vocal and dance and starts to summate fuel injection, ignition timing, transmission shift points, etc. in conjunction with the MAP sensor, PIP sensor, engine coolant sensor and then on and on.
  7. This process of informing the ECM of throttle plate angle goes on the whole fourth dimension the engine is running.

Pretty elementary stuff, no? Well testing it is simply as simple. Since you'll be working in the engine compartment, no demand to tell you (just I'k gonna' tell you lot anyway) to be alert and be very conscientious. Use mutual sense and take all necessary safe precautions. OK, let'due south get this show on the route, get to: TEST 1: Testing The TP Signal With A Multimeter.

Where To Buy The TPS And Save

The TPS isn't too expensive, if y'all buy information technology at your local motorcar parts. Check out the following links. I think they'll save you a few bucks:

Not sure if the to a higher place TPS fits your particular Ford? Don't worry, once you get to the site they'll make sure information technology fits past asking yous the specifics of your particular Nissan vehicle. If information technology doesn't fit, they'll observe y'all the right 1.