EN

Severity: High Code type: Generic (all makes)

U0107 Code: Lost Communication With Throttle Actuator Control Module

The engine computer can't reach the module that drives the electronic throttle, so power is cut back.

At a glance

Severity: 4/5 – High4/5

Severity: High

Meaning
Lost Communication With Throttle Actuator Control Module
System
Module Communication · Network
Safe to drive?
With caution
Typical repair cost
$50–$1,600
DIY difficulty
Moderate

With drive-by-wire, a motor opens the throttle plate based on your pedal input, and a throttle actuator control (TAC) module runs that motor. On most current cars that logic lives inside the ECM, so U0107 is uncommon; it shows up mainly on vehicles where the TAC module is a separate box that talks to the PCM over a network or dedicated data link, such as early electronic-throttle V8 trucks and SUVs. When the PCM loses those messages it can no longer trust throttle position, so it goes into a reduced-power mode: the throttle is either held at a small fixed opening by its return springs or limited to a slow response. Because the module is usually in the engine bay, heat, water and connector corrosion play a big part, along with low system voltage.

How to read U0107

How to read U0107U10213074
  1. U Network
  2. 0 Generic (SAE)
  3. 1 Module Communication
  4. 07 Specific fault

Symptoms

  • 'Reduced Engine Power' or throttle warning on the dash
  • Pedal has little or no effect; car barely accelerates
  • Idle stuck around a fixed speed or surging
  • Engine stalls when coming to a stop on some vehicles
  • Check engine light with throttle or pedal correlation codes
  • Cruise control disabled

Possible causes

Ranked by how often each cause is behind this code (editorial estimate).

  1. Corroded or loose connector at the TAC module or throttle body 24%
  2. Low or unstable battery/charging voltage 20%
  3. Blown fuse or poor ground feeding the TAC module 18%
  4. Internal TAC module failure from heat or vibration 18%
  5. Damaged data or CAN wiring between the TAC module and the PCM 14%
  6. PCM fault or wrong software after a PCM replacement 6%

Diagnosis step by step

Diagnostic flow: U01071Confirm your vehicle has a separateTAC module2Read throttle data3Test power and ground at the module4Inspect connectors at the module andthrottle body5Check the data link to the PCM6Replace module and relearn

  1. Confirm your vehicle has a separate TAC module

    Check the service information. If throttle control is built into the ECM, U0107 points to an ECM power or software issue rather than a separate box; if there is a standalone module, find where it's mounted and how it links to the PCM.

    Tools: OBD-II scanner

  2. Read throttle data

    Look at commanded versus actual throttle position and both pedal sensor signals. If the module answers but data freeze or drop out while you wiggle its harness, suspect the connector or wiring.

    Tools: OBD-II scanner

  3. Test power and ground at the module

    With the key on, back-probe the supply pins for battery voltage and do a voltage-drop test on the ground while cycling the throttle; the motor current makes a weak ground show up clearly. More than about 0.1 V on the ground side is too much.

    Tools: Multimeter

  4. Inspect connectors at the module and throttle body

    Unplug the TAC module and the throttle body connector and look for green corrosion, water and spread terminals. Engine-bay connectors near the battery or washer bottle are frequent offenders.

    Tools: Flashlight, Screwdriver

  5. Check the data link to the PCM

    Measure the network lines between the TAC module and PCM for the expected bias voltage with the key on and for continuity and shorts to ground with the battery off. A break here makes the PCM lose the module even though it has power.

    Tools: Multimeter

  6. Replace module and relearn

    If power, ground, connectors and link wiring are good, replace the TAC module. Afterwards run the throttle relearn (key on, then idle relearn) as the manufacturer specifies.

    Tools: OBD-II scanner

Where the parts are

Charging system and control modules – U01071234567
Charging system and control modules
  1. 1Battery
  2. 2Alternator
  3. 3Engine computer (ECM)
  4. 4CAN bus
  5. 5Transmission
  6. 6Wheel speed sensor
  7. 7High-voltage battery

Repair options & costs

RepairDIY?Estimated cost
Clean/repair TAC or throttle body connector Yes $50–$250
Repair data link or supply wiring No $150–$450
Replace TAC module with relearn No $300–$800
Replace PCM with integrated throttle control and program No $700–$1,600

Rough US estimates for parts and labor; shop rates vary by region. Not a quote.

Notes by brand

Chevrolet

Early drive-by-wire full-size trucks and SUVs with V8 engines used a separate TAC module mounted in the engine bay; later generations moved throttle control into the ECM, which is why U0107 is mostly seen on those older trucks.

Emissions / smog test impact

Will fail

U0107 turns on the check engine light and affects throttle and emissions control, so the vehicle fails a US emissions test until it's repaired and readiness monitors complete.

Frequently asked questions

Why does my car only idle with U0107?

Without trustworthy throttle data the PCM can't safely open the throttle. It falls back to a spring-held position or tightly limited opening, which is just enough to move the car slowly.

Is U0107 the same as a bad throttle body?

No. A bad throttle body usually sets throttle performance or position codes. U0107 means the PCM lost contact with the module that controls the throttle, which is a wiring, power or module problem.

Why is U0107 so rare on newer cars?

Most manufacturers now build throttle control into the ECM, so there's no separate module to lose. On those cars the code is unusual, and the service manual should be checked to see what it refers to.

Do I need a relearn after the repair?

Usually yes. After replacing the module or throttle body, the system needs to learn the throttle's closed position, or you'll get a high idle or stalling.

Sources