U0107 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.

Definition

OBDII Code U0107 - Lost Communication With Throttle Actuator Control Module

Meaning 

Let’s start with a bit of automotive technology history so you can understand the problem and its solution. Once upon a time in Motown (and other car manufacturing hubs around the world), automobiles uses a mechanical throttle linkage to connect the gas pedal to the throttle on the engine. 

In the modern era, the throttle linkage has been eliminated by an electronic throttle body. A major drawback of mechanical throttle linkages is they could bind up over time due to wear, insufficient lubrication, rust, etc. Electronic throttle bodies don’t suffer from these drawbacks, and they improve fuel economy and emissions, too.

Here’s how a modern throttle works on a car: the electronic throttle body is wired up to multiple TP (throttle plate) sensors, and these sensors determine the throttle plate angle (i.e. how far down you are pushing the gas pedal/opening the throttle). 

These coordinate with APP (Accelerator Pedal Position) sensors are used to calculate throttle accelerator pedal position, all of which transfer their data to the TAC (throttle actuator control) and control of the throttle motor.

All these processes and sensors are used to make your car accelerate.

The TAC communicates with the other control modules throughout the vehicle via a network called the Controller Area Network (CAN) bus.

Every CAN bus consists of two lines: CAN High and CAN Low. CAN high communicates at a faster 500k bits/second, whereas CAN Low communicates at 125k bits/second. The ends of the CAN bus contain two terminating resistors to close the circuit.

When this connection is lost or compromised in some way, your vehicle will illuminate the check engine light and save trouble code U0107.

In simplest terms, the throttle actuator control that makes your vehicle accelerate is no longer talking to the other controllers on the network.

Causes

  • A dead battery (fairly common problem)
  • A faulty TAC module (less common problem)
  • A problem with TAC module circuit (fairly common problem)
  • A problem with the CAN bus (if this is the case you will often see multiple trouble codes pop up)

Symptoms

  • Illuminated warning lights (check your dashboard)
  • TAC-related performance issues (your vehicle will experience acceleration problems or not run at full power)

Diagnosis

Diagnosing the problem requires a few preliminary checks before you can track down the root cause.

Sometimes U0107 can pop up intermittently due to connection or control module issues, or it can result from a dead battery that isn’t pushing sufficient voltage to the system.

This is likely the cause if the code pops up in code history but not as an active trouble code. Our technicians always start with a battery test if they see a U0100-0300 trouble code to eliminate the possibility first.

Next,  our technician clears the code and checks to see if it recurs. If the code pops up again, it’s time for a close visual inspection of the throttle actuator module and CAN bus connections. A trained eye is much more effective at spotting loose wiring or worn connections

If our technician finds a problem with the wiring or connectors, it’s a quick fix, and they clear the code again.

If there’s nothing relevant found during that visual inspection but the code is still coming up after reset, our technician checks for technical service bulletins (TSBs).

 TSBs are documents put out by vehicle manufacturers that detail specific diagnostic and repair protocols for known issues. Checking TSBs saves time and often resolves problems without the need for labor intensive and expensive repairs.

Once our tech finds the source of the problem, it’s time to determine what will be needed to fix the problem.

Common mistakes

The most common error most techs make is to skip a standard automotive battery test.

If you are verifying any U0100 to U0300 trouble codes, a standard battery check should be among the first things a competent technician does.

How serious

When your vehicle pops a U0107, it forces your vehicle to run in reduced power mode. Your throttle will react sluggishly and acceleration will take longer.

What repairs can fix the code

  • Repair/replace wiring
  • Repair/replace CAN bus connectors
  • Reprogram the TAC module
  • Replace the TAC module

Related codes

All the 'U' codes are network communication codes. Codes U0100 to U0300 are lost communication with XX module codes.

If you are seeing any trouble codes in that range, chances are you have some type of CAN bus or controller network problem.

You should immediately test the vehicle battery, but be prepared to check all network connections or have them checked by a professional.

Conclusion

U0107 is a simple enough problem to diagnose, and it doesn’t necessarily mean an expensive repair or replacement.

That being said, if you are seeing any of these trouble codes come up on your home OBDII scanner, your car needs a thorough checkup from a trained professional.

Make an appointment right away to avoid potentially more time-consuming and expensive repairs.

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