How To Test a Mazda B2300 TPS Sensor

How To Test a Mazda B2300 TPS Sensor


When your Mazda B2300 TPS sensor begins to fail, it can cause a bunch of issues with your light duty truck. The TPS is also known as the throttle position sensor, and it’s a vital part of your Mazda EFI system. Your 2.3 liter engine is the same found in Ford vehicles, and it’s a basic three pin unit mounted on your throttle body.

Today I will be showing you how to test your throttle position sensor in a 1997 Mazda B2300 truck. Equipped with the 4 cylinder 2.3 liter engine, this sensor reads the position of your throttle blade and communicates this as a voltage to your Mazda ECU.

how to test mazda b2300 tps sensor

If your Mazda B2300 TPS sensor begins to go bad, you will start seeing all kinds of problems with your truck. Some of these symptoms can be dangerous, especially if your truck is equipped with an automatic transmission.

Symptoms of a failing Mazda B2300 TPS Sensor

When the throttle position sensor in your Mazda is going bad, your truck will begin to respond to throttle input slower. Over time the bad sensor can cause misfire or cause your engine speed (RPM) to increase on it’s own. Here are some of the more common problems you will encounter when your throttle sensor starts going south.

  1. CEL or MIL Status
  2. Prematurely failed catalytic converter
  3. Poor gas mileage
  4. Inconsistent throttle response

When your throttle position sensor is going bad, you can use our handy guide to troubleshoot the B2300 TPS Sensor. To complete our DIY guide, you will need to use an automotive multimeter. If you are not sure what that is or how to use one, check our guide here.

Check your Mazda B2300 TPS Sensor for Power

Before you can begin testing your throttle position sensor, you will need to open your truck hood and locate the TPS. The throttle sensor is mounted opposite of the throttle butterfly, and connected by way to a three pin weatherproof connector.

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Follow your air intake tract until you reach the throttle body, and you should see the B2300 TPS Sensor. You will begin by testing the power wire using your multimeter. Now turn the Mazda truck ignition to the “ON” position. Put the black lead of your multimeter to the negative terminal of your battery, and then pierce PIN A.

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PIN A is a BROWN wire with a WHITE stripe in it, and there should be 5 volts DC at this wire. If you have a power signal here, you should check for a low reference ground signal. The next wire to check is PIN C, which is a GRAY wire with a RED stripe. There should be a ground signal present at this wire. If you have both power and ground, your B2300 TPS Sensor should be working correctly.

Check Signal on your Mazda B2300 TPS Sensor

If you have power and ground at these two wires, you must check to make sure that the signal is within specifications. Leave the ignition key turned to the “ON” position and check the middle wire, which is PIN B. This is a GRAY wire with a WHITE stripe for the signal wire of your B2300 TPS sensor.

You should see DC voltage value around .9 volts with the throttle plate closed. Now push down on the throttle butterfly to open the throttle body fully. With the throttle completely opened you should see a voltage range between 4.6-4.9 volts DC.

If you see the voltage within these specifications, your TPS sensor should be working correctly. Keep in mind that these values are not set in stone, and chances are that your truck voltage will vary slightly. When you see your truck throttle sensor voltage is not within this range, you must replace the TPS with a replacement part.

Have any questions about our How To guide on replacing the Mazda B2300 throttle sensor? Leave them for us below and let us know!