CAN network

U0107 — Lost Communication with Throttle Actuator Control Module

Severity: high Drive with care, to a shop

What U0107 means

U0107 means the powertrain control module (PCM) stopped receiving messages from the throttle actuator control (TAC) module over the CAN bus. Normally the PCM sends the requested throttle position based on the pedal, and the module reports back the actual position. If that exchange fails, the PCM can't control the throttle safely and limits engine power.

Symptoms

  • Check Engine light on
  • Electronic throttle control warning light
  • Weak or no throttle response
  • Limp mode with reduced engine power
  • Erratic idle
  • Sluggish acceleration
  • Hard starting or stalling in some cases

Possible causes

  1. Open or short in the CAN bus wiring, or poor connector contact
  2. Failed TAC module or throttle body with built-in module
  3. Poor power or ground at the throttle module
  4. Blown fuse in the electronic throttle (ETCS) circuit
  5. Low system voltage at start from a weak battery or bad terminals
  6. Damaged engine bay harness (chafing, moisture, corrosion)
  7. PCM software fault or CAN interface problem

How to diagnose

  1. Scan all modules and save freeze-frame data; note any other U-codes or throttle and pedal codes
  2. Test the battery and inspect terminals for proper voltage and clean, tight connections
  3. Check the fuses and relays for the electronic throttle circuit
  4. Inspect the throttle connector and engine bay harness for chafing, corrosion, moisture, or past repairs
  5. Use a multimeter to check power and ground at the throttle module connector
  6. Test CAN High and CAN Low for continuity and resistance (typically about 60 ohms across the pair with the ignition off)
  7. See whether the scan tool can communicate with the throttle module at all
  8. Check for software updates for the PCM and module, then clear the code and road test

Common fixes

  • Repair or replace damaged CAN wiring and connectors
  • Replace the faulty TAC module or throttle body, then perform the throttle relearn
  • Clean and tighten power and ground connections, replace the blown fuse
  • Update or reprogram the PCM and module software
  • Replace the battery or service the terminals if low voltage is the cause

Questions and answers

What does U0107 mean?

It means the engine computer lost CAN communication with the throttle actuator control module. The cause is usually wiring, power or ground, or the module itself.

Can I drive with code U0107?

Only carefully and for a short distance. Engine power is limited and the throttle may not respond, so have it checked as soon as possible.

How do I clear U0107?

Clearing it with a scan tool is only temporary. If the cause is not fixed, such as a CAN fault, bad ground, or failed module, the code will come back, so find the fault first.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.