Duramax Throttle Position Sensor

Duramax Throttle Position Sensor Problems [07 Problems]

The Duramax throttle position sensor (TPS) plays a crucial role in Duramax diesel engines. It communicates the position of the throttle valve to the engine control module (ECM). Using this TPS input, the ECM calculates the optimal fuel, timing, and other settings for peak engine performance.

When the TPS goes terribly, it can create various drivability and performance problems in your 07 Duramax. Below, I’ll go over the 7 most frequent issues caused by a faulty throttle position sensor.

7 Duramax Throttle Position Sensor Problems

A bad TPS can cause various drivability and performance issues in your 07 Duramax truck. Here are the 7 most common problems caused by a faulty throttle position sensor:

Acceleration Issue

One of the most evident signs of a bad TPS is sluggish or jerky acceleration. When you step on the gas, the engine may hesitate momentarily before picking up speed. You’ll notice a lag between pressing the pedal and the truck accelerating. This happens because the faulty TPS isn’t giving the ECM accurate data on the throttle valve position. So, the computer can’t correctly calculate the ideal fuel and timing for smooth acceleration. 

Fuel Efficiency

With a malfunctioning TPS, your Duramax may get worse gas mileage than usual. Since the ECM needs to get precise throttle data for its fuel calculations, it ends up delivering too much or too little fuel. Excess fuel makes combustion less efficient, reducing mileage. On the flip side, inadequate fuel creates a lean mixture and misfires, again sapping fuel efficiency.

Check Engine Warning Light

A defective throttle position sensor can switch on the check engine light on the dashboard. It triggers diagnostic trouble code (DTC) P0122 for “TPS Circuit Low Voltage” or P0123 for “TPS Circuit High Voltage”. These codes mean the TPS signal voltage is outside the normal working range. When the truck’s On-Board Diagnostics detects this, it turns on the check engine light. You can also Check for Duramax code p0380 and its causes and solutions.

 Miscalculated Position of Throttle Valve

The ECM determines the throttle valve position based on the TPS signal voltage. When the TPS is faulty, it provides incorrect voltage signals to the computer.

As a result, the ECM miscalculates the actual throttle position. This wrong information leads to poor engine performance, acceleration issues, reduced power, etc.

Flat Signal from the Sensor

Duramax Throttle Position Sensor

Some faulty TPS units send a steady flat signal instead of changing voltage based on throttle movement. This balanced signal fools the ECM into thinking the throttle is at the same position all the time.

Such false constant TPS data confuses the computer, and it can’t optimize fuel delivery and ignition timing accurately. The engine may stall, misfire, hesitate, or have power loss.

Unstable Engine Idling

As the name suggests, the throttle position sensor also monitors the throttle position at idle. The ECM needs this data to keep the engine idling smoothly.

A bad TPS provides erroneous throttle position information at idle speed. This causes unstable idling with occasional rpm surges or dips. The engine may hunt for the correct idle speed.

Improper Gear Shifting

The transmission control module (TCM) relies on throttle position sensor data for smooth gear shifting. When the TPS readings are erratic, the TCM gets confused and causes abrupt or delayed gear shifts.

So, if your Duramax truck has harsh gear engagement or flared shifts, the root cause may be a faulty throttle position sensor.

Can I Drive with a Bad Throttle Position Sensor in My Duramax?

You can drive a Duramax truck with a bad TPS, but doing so is not recommended. A faulty throttle position sensor can seriously hamper engine performance and drivability. Plus, it may cause safety issues due to unpredictable power delivery.

Here are some specific risks of driving with a defective TPS:

  • Sudden acceleration or deceleration leading to accidents
  • Getting stranded when the engine stalls unexpectedly
  • Catalytic converter damage from misfiring or fuel richness
  • Increased emissions and reduced fuel economy
  • Further deterioration of the throttle position sensor

So get your Duramax checked and replace the faulty TPS as soon as possible. Driving short distances to the repair shop is okay, but avoid any long trips before fixing the problem.

If the check engine light is on with a TPS-related code, have it diagnosed and repaired promptly. The OBD warning indicates a real issue with your throttle control system.

02 Solutions for Throttle Position Sensor Problems

How to Replace a Throttle Position Sensor: Reinstalling the TPS

If your 07 Duramax truck has symptoms of a bad throttle position sensor, there are two solutions:

Reinstalling the TPS

Reinstalling or replacing the TPS often fixes the problem and restores proper engine performance. Let’s look at both solutions in detail:

Reinstalling the TPS

Before replacing the TPS, try reinstalling the existing sensor properly. This may resolve the issue if the sensor isn’t secured correctly or has loose electrical connections.

Reinstalling the Process of a Throttle Position Sensor

Here are the steps to reinstall a TPS:

  1. Turn the ignition off and disconnect the negative battery cable.
  2. Unplug the electrical connector from the TPS unit.
  3. Remove the two screws that hold the sensor to the throttle body.
  4. Carefully pull out the TPS from the throttle body.
  5. Check the sensor and throttle body mating areas for carbon deposits or damage. Clean with a throttle body cleaner if required.
  6. Apply a light coat of anti-seize compound on the TPS mounting holes and electrical connector.
  7. Install the sensor in the throttle body, ensuring proper alignment.
  8. Secure the TPS tightly with the mounting screws as per the specified torque.
  9. Reconnect the electrical connector, ensuring it clicks and locks in place.
  10. Reconnect the battery cable and turn the ignition on to clear any error codes.

This thorough reinstallation allows the TPS to function correctly again in many cases. But if the issue persists, replacing the sensor is needed.

Replacing the TPS

If reinstalling doesn’t solve the problem, the TPS itself is faulty and requires replacement. Installation of a new throttle position sensor is recommended to fix the following issues permanently:

  • Erratic or inaccurate voltage signals
  • Out-of-range TPS voltage
  • Constant unchanging voltage
  • Internal failures causing incorrect readings
  • Physical damage to the sensor housing or electrical contacts

Follow the mounting instructions above to remove the faulty TPS and install a genuine Duramax replacement part. Make sure to transfer any shims or spacers from the old sensor.

After installation, reconnect the battery and allow the ECM to reset and relearn the new TPS. Test drives your Duramax to ensure throttle response and performance returns to normal.

10 Steps- How to Replace a Throttle Position Sensor [DIY Method]

Here are the critical steps for the DIY replacement of a faulty throttle position sensor on your Duramax diesel truck:

  1. Turn off the ignition and disconnect the negative battery cable.
  2. Clean any dirt or grease buildup around the throttle body.
  3. Trace the TPS wiring harness and unplug the electrical connector.
  4. Remove the two TPS mounting screws and carefully pull it out of the throttle body.
  5. Inspect the throttle body area and use a throttle cleaner to remove carbon deposits if required.
  6. Install the new TPS in the throttle body, ensuring proper orientation.
  7. Apply thread locker on the screws and tighten them to the specified torque.
  8. Reconnect the TPS wiring harness and make sure it clicks securely in place.
  9. Reinstall the battery cable, turn on the ignition, and clear any diagnostic trouble codes.
  10. Test drives the truck to verify regular throttle operation without any issues.

Take basic safety precautions when working on the TPS. And make sure to get the sensor from a reputable source to avoid getting a defective replacement part.

Price of a Duramax Throttle Position Sensor

A factory original GM throttle position sensor for Duramax engines typically costs between $90 to $150. Aftermarket and direct replacement TPS sensors are available between $50 to $100.

The TPS price depends on the sensor brand, manufacturing quality, materials used, and seller. Some key factors impacting the Duramax throttle position sensor cost are:

  • OE vs. Aftermarket: Original GM sensors are costlier than aftermarket ones.
  • Sensor Quality: Premium sensors made with higher-grade components cost more.
  • Materials: Sensors with corrosion-resistant metal housing and connections are pricier.
  • Seller’s Reputation: Duramax parts from reputable sellers cost more than obscure brands.
  • Package Inclusions: Sensors that come with extra installation hardware and components cost extra.
  • Shipping Charges: Overnight or expedited shipping can increase throttle position sensor costs.

If you want to buy a Duramax Throttle Position Sensor, we highly recommend Autozone. It is a trusted and reputable source for automotive parts and accessories, and it offers a wide range of high-quality products to meet your needs.

What are the most common throttle position sensor problems in Duramax engines?

The most common TPS issues in Duramax trucks are:

Acceleration hesitation.
Jerky throttle response.
Check engine light.
Improper gear shifting.
Unstable idle speed.
Reduced power and mileage.
Engine misfires.

Expected Questions on TSP Problems

Here are answers to some frequently asked questions about Duramax throttle position sensor issues:

What Problems Can a Bad Throttle Position Sensor Cause?

A faulty TPS can cause poor acceleration, jerky throttle response, check engine light, incorrect gear shifting, reduced power, engine misfires, stalling, unstable idle speed, and reduced fuel economy in Duramax trucks.

Can a Throttle Position Sensor Problem Change Every Time?

Yes, the symptoms of a faulty throttle position sensor may vary based on driving conditions. Issues like hesitation, stalling, or power loss can happen intermittently, making the problem hard to diagnose.

Will Bad Throttle Position Sensor Cause Transmission Problems?

A bad TPS can indirectly cause transmission problems in Duramax trucks. It provides wrong signals to the engine computer, which then relays incorrect data to the transmission control module. This results in abnormal gear shifting, slipping, or hard shifts due to the confused TCM.


The Duramax throttle position sensor is a minor component but plays a significant role in the proper functioning of Duramax diesel engines. A faulty TPS causes poor drivability, reduced power, decreased fuel economy, and other driveability complaints.

Diagnosing the symptoms accurately and replacing the defective sensor promptly can restore normal performance. While a bad TPS doesn’t lead to complete engine failure, it’s better to fix it fast to avoid dangerous situations on the road.

With proper troubleshooting and sensor replacement, your 07 Duramax engine will run smoothly for years to come. Choose a high-quality TPS and install it correctly to get the optimal performance from your truck.

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