What Does The Throttle Position Sensor Do? (1.5L Honda Civic)

The throttle position sensor (TPS) is an essential component of your 1.5L Honda Civic's engine management system. It's one of many input sensors the fuel injection computer relies on to efficiently and optimally keep the engine running.

This article will answer some of the most commonly asked questions about the throttle position sensor on the 1.5L Honda Civic.

APPLIES TO: This tutorial applies to the following vehicles:

• 1.5L Honda Civic: 1992, 1993, 1994, 1995.
• 1.5L Honda Civic del Sol: 1993, 1994, 1995.

What Does The Throttle Position Sensor (TPS) Do?

The throttle position sensor measures the throttle plate angle as you step on or step off the accelerator pedal. This throttle angle information is then sent to the fuel injection computer.

Here are some more specifics:

• When the throttle plate is closed, the throttle position sensor produces a voltage value around 0.5 to 0.9 Volts DC.
• As the throttle plate opens, the voltage output of the TPS increases.
• At wide-open throttle (WOT), the TPS signal voltage output is around 4.5 to 4.9 Volts DC.

In a nutshell, the TPS voltage value increases/decreases as the throttle plate opens/closes.

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

When the throttle position sensor fails, it will simply stop measuring the throttle plate angle.

The fuel injection computer will default to preprogrammed TPS values without any throttle plate angle information.

The end result of a faulty TPS is drivability and engine performance problems.

In the next section, you'll find a list of common symptoms you'll see when the TPS fails.

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

When the throttle position sensor fails, you'll see one or more of the following symptoms:

• Check engine light illuminated in the instrument cluster.
• TPS trouble codes registered in the fuel injection computer's memory:
  • Code 7: Throttle Position Sensor.
• 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 you can be 100% positive that the throttle position sensor has failed is to test it.

Specifically, you need to see if its output signal is stuck in one value as the throttle plate opens/closes.

If the TPS voltage signal output does not correspond to the actual throttle plate angle, you can conclude that it has failed.

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

Can I Test The Throttle Position Sensor?

You can easily and quickly test the TPS with a multimeter. You don't need any expensive or exotic diagnostic testing equipment.

Here's the TPS test procedure:

1. Check for TPS diagnostic trouble codes stored in the fuel injection computer's memory.
2. Make sure that the TPS is getting power.
3. Make sure that the TPS is getting Ground.
4. Ensure that the TPS voltage signal increases/decreases as the throttle plate opens/closes.

If the TPS is bad, its output voltage signal will not increase/decrease as you open/close the throttle plate.

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

• How To Test The Throttle Position Sensor (1992-1995 1.5L Honda Civic).

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

The fuel injection computer will activate its 'limp' mode when the throttle position sensor fails.

'Limp' mode limits your Honda Civic's engine performance to a considerable degree to ensure the TPS fault doesn't cause any engine damage.

Depending on the severity of the symptoms that the 'limp' mode or the faulty throttle position sensor is causing, your Honda Civic will not be safe to drive.

Where Can I Buy The Throttle Position Sensor (TPS)?

The following links will help you to comparison shop for the throttle position sensor:

More 1.5L Honda Civic Tutorials

You can find a complete list of 1.5L Honda Civic tutorials in this index:

• 1.5L Honda Civic Index Of Articles.

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

• How To Test The PGM-FI Main Relay (1992-1995 1.5L Honda Civic).
• How To Test The Fuel Injectors (1992-1995 1.5L Honda Civic).
• How To Test For A Blown Head Gasket (1.5L Honda Civic).
• How To Test Engine Compression (1992-1995 1.5L Honda Civic).