U0107
Lost Communication with Throttle Actuator Control Module
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Code U0107 indicates that the powertrain control module has lost communication with the Throttle Actuator Control (TAC) module. In modern vehicles with electronic throttle control (drive-by-wire), there is no physical cable between the accelerator pedal and the throttle body. Instead, the TAC module receives commands from the PCM over the CAN bus to open and close the throttle. When this communication link breaks, the vehicle loses the ability to control engine power.
This is a high-severity code because it directly affects your ability to accelerate. The most common experience is that the engine will idle normally but pressing the gas pedal does nothing. Some vehicles will enter a severe limp mode that limits speed to 5-10 mph for emergency driving, while others will be completely immobile. In rare cases, the throttle may behave erratically, which creates a genuine safety hazard.
Do not attempt to drive the vehicle at normal speeds with this code active. Have it towed to a repair facility if throttle response is lost. The diagnostic process starts with checking the TAC module's power supply and CAN bus connections. Wiring and connector issues are the most common cause, and the repair is often a connector cleaning or wire repair. If the TAC module itself has failed, replacement typically runs $200-$500 for the part, plus programming may be required.
Severity
Symptoms
- •Engine idles normally but does not respond to accelerator pedal input
- •Reduced engine power warning or limp mode activated
- •Vehicle unable to accelerate beyond very low speed
- •Throttle warning light or lightning bolt symbol on dashboard
- •Engine may rev unexpectedly or surge without pedal input
- •Complete loss of throttle response requiring the vehicle to be towed
Likely Causes
The wiring between the Throttle Actuator Control module and the main CAN bus can corrode at connectors or break from engine vibration. Even a single bad pin in the CAN bus connector can cause the entire module to drop off the network.
The TAC module contains power electronics that drive the electronic throttle motor. These components are subjected to engine heat and vibration and can fail, preventing the module from communicating its status or receiving commands.
A weak battery, blown fuse, or voltage spike from a failing alternator can cause the TAC module to reset or shut down. The module requires stable voltage to maintain both throttle control and CAN bus communication.
While the throttle body itself doesn't communicate on the CAN bus, a shorted throttle motor or position sensor can damage the TAC module's driver circuits, causing it to fail and drop off the bus.
Estimated Cost
Professional Repair
Includes parts + labor
Common Fixes
- Inspect the TAC module connector for corroded, bent, or damaged pins
- Check and replace any blown fuses in the TAC module power circuit
- Verify battery voltage is above 12.4V and alternator output is stable
- Test CAN bus wiring continuity between the TAC module and the PCM
- Replace the Throttle Actuator Control Module if electrical tests pass