What Does The Throttle Position Sensor Do? (Ford E150, E250, E350)

Your Ford E150 (E250, E350) comes equipped with a throttle position sensor (TPS).

It's one of the critical engine management components that your van's fuel injection computer uses to optimally and efficiently manage engine operation.

In this article I'll cover some of the most frequently asked questions about the TPS.

APPLIES TO: This tutorial applies to the following vehicles:

• Ford E150: 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996.
• Ford E250: 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996.
• Ford E350: 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996.

What Does The Throttle Position Sensor (TPS) Do?

The throttle position sensor is tasked with informing the computer how much the throttle plate opens and closes as you step on or off the accelerator pedal.

This throttle plate angle information is critical for your Ford E-Series van's engine management system.

With the TPS signal input, the fuel injection computer can now manage a host of functions necessary to keep the engine running optimally and efficiently.

What Happens When The Throttle Position Sensor (TPS) Goes Bad?

When the throttle position sensor stops functioning, your Ford E-Series van's fuel injection computer is deprived of the throttle plate angle information it needs to keep the engine running efficiently and optimally.

The end result is that your Ford van's engine is going to suffer engine performance, driveability, and emissions problems.

In the next section, I'll list some of the symptoms you'll see when the throttle position sensor fails.

What Problems Can A Throttle Position Sensor (TPS) Cause?

When the throttle position sensor fails on your Ford E150 (E250, E350) you'll see one or more of the following symptoms:

• Check engine light illuminated in the instrument cluster.
• OBD 1 TPS trouble codes registered in the fuel injection computer's memory:
  • Code 23: Throttle Position (TP) Circuit Performance Problem.
  • Code 53: Throttle Position (TP) Circuit High Input.
  • Code 63: Throttle Position (TP) Circuit Low Input.
• OBD 2 TPS trouble codes registered in the fuel injection computer's memory:
  • Code 121: Throttle Position (TP) Circuit Performance Problem.
  • Code 122: Throttle Position (TP) Circuit Low Input.
  • Code 123: Throttle Position (TP) Circuit High Input.
• Engine hesitates when you step on the accelerator pedal.
• Lack of power when accelerating the vehicle.
• Bad gas mileage.
• Engine idle either too high or too low.
• Rough engine idle.
• The engine may start and immediately stall.
• The engine cranks but does not start.

How Can You Tell If The Throttle Position Sensor (TPS) Is Bad?

The only way to find out if the throttle position sensor has failed, is by testing it.

The cool thing is, that testing the TPS is not complicated nor difficult. Not to mention that it can be tested accurately with a simple multimeter.

In the next section, I'll go into some of the specifics of the TPS test.

How Can I Find Out If The Throttle Position Sensor (TPS) Is Bad?

Thankfully testing the throttle position sensor is pretty easy. The best part of all, is that you don't need any expensive diagnostic equipment.

In a nutshell, this is what the test involves:

1. Checking for TPS trouble codes stored in the fuel injection computer's memory.
2. Making sure that the TPS is getting power.
3. Making sure that the TPS is getting Ground.
4. Making sure that the TPS signal increases/decreases as the throttle plate is opened/closed.

You can find the throttle position sensor test explained in a step-by-step manner here:

• How To Test: Throttle Position Sensor (1988-1995 Ford 4.9L).
• How To Test The Throttle Position Sensor (Ford 5.0L, 5.8L) (at: easyautodiagnostics.com).

Can I Drive My Van With A Bad Throttle Position Sensor (TPS)?

In most cases, the engine performance problems caused by a bad TPS will not allow you to safely drive the vehicle.

But, even if the vehicle can be driven, you should avoid doing so.

More Ford E150, E250, and E350 Tutorials

You can find a complete list of tutorials for the full-size Ford E-Series vans here: Ford 4.9L, 5.0L, 5.9L Index Of Articles.

Here's a small sample of the tutorials you'll find:

• Manifold Absolute Pressure MAP Sensor Test (Ford 4.9L, 5.0L, 5.8L).
• Ignition Coil Test -No Spark No Start Tests (Ford 4.9L, 5.0L, 5.8L).
• How To Troubleshoot A No Start (Ford 4.9L, 5.0L, 5.8L).
• Testing A Blown Head Gasket (Ford 4.9L, 5.0L, 5.8L).
• How To Test Engine Compression (4.9L, 5.0L, 5.8L).