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DTC codes / U01xx · Lost communication with a control module / U011E

U011ELost Communication With Throttle Actuator B Control Module

U011E is a network communication fault indicating that a control module on the vehicle's data bus has lost contact with the Throttle Actuator B Control Module, which is the electronic throttle body or a dedicated module that drives it. The computer detected that expected messages from that module stopped arriving within the required time window, so it flagged the communication loss rather than a direct throttle malfunction.

SystemNetwork
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyProfessional
AreaLost communication with a control module

Symptoms you may notice

  • Illumination of the check engine light or a dedicated throttle control warning lamp
  • Reduced engine power or limp-home mode with a noticeably sluggish accelerator response
  • The engine may idle erratically or stall when coming to a stop
  • Often no symptoms besides the warning light, especially if the fault is intermittent
  • Other unrelated warning lights may appear if the lost module shares a bus segment with other systems

Common causes, most likely first

  1. Damaged, corroded, or loose wiring or connector pins at the throttle actuator module or its harness
  2. A failed throttle actuator control module or electronic throttle body assembly
  3. Blown fuse or poor ground connection supplying power to the throttle actuator module
  4. CAN bus wiring fault such as an open, short, or chafed wire between the module and the network
  5. Low battery voltage or a weak charging system causing modules to drop offline intermittently
  6. A software or calibration issue in the throttle actuator module or another module on the same bus

How to diagnose and fix it

  1. Scan all modules for communication codes and record which modules are online to map the affected bus segment
  2. Inspect the throttle actuator module connector and harness for corrosion, pushed pins, or chafed wiring
  3. Check the fuse and ground circuit feeding the throttle actuator module with a multimeter under load
  4. Measure CAN bus resistance and voltage at the module connector to confirm the network is intact
  5. Perform a wiggle test on the harness while watching live data to catch intermittent communication drops
  6. If wiring and power are good, substitute a known-good throttle actuator module or reflash the existing module
  7. Clear codes and verify communication returns with a road test and a full module scan

What most technicians miss on U011E

  • A loose or corroded ground at the throttle actuator module is a frequent culprit that looks like a failed module but costs almost nothing to fix.
  • Intermittent U011E codes often trace to low battery voltage during cranking, so test the battery and charging system before condemning any module.
  • The code does not always mean the throttle body itself is bad; the module may be healthy but isolated by a single chafed CAN wire.
  • Some vehicles set U011E when a related module on the same bus segment fails, so scan every module before ordering parts.
  • After replacing a module, a relearn or calibration procedure is often required, and skipping it can leave the throttle response poor even with communication restored.

Can I keep driving with U011E?

You can usually drive cautiously to a repair shop if the vehicle is not in limp mode, but avoid heavy acceleration and highway merging because throttle response may be unpredictable. If the engine stalls, idles erratically, or the vehicle enters reduced power mode, stop driving and arrange a tow.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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