01 Exploring the Inner Workings of Engine Pistons: A Complete … • 02 The Wankel Rotary Engine: Compact, Smooth, and Powerful • 03 Why Your Car Suddenly Feels Slower Even Though Nothing Seem… • 04 How to tell if your spark plugs are bad: Signs, symptoms, a… • 05 Is it Bad to Pump Your Brakes When The Car is Off? • 06 At What Mileage Do Most Cars Start Having Issues? • 07 BMW Unveils New Armored i7 and V8 7 Series for High-Profile… • 08 Revving Up the Future: Automotive Industry Trends 2024-2026 • 09 Converting a Petrol Car to LPG: Benefits, Process, and Cons… • 10 The Hidden Pattern Behind Intermittent Dashboard Warnings •

DTC codes / U02xx · Lost communication with a control module / U0293

U0293Lost Communication with Hybrid Vehicle Control System

U0293 is a generic communication fault that sets when the engine control module (ECM) or another primary module stops receiving valid controller area network (CAN) messages from the hybrid vehicle control system. The code means the hybrid controller is either offline, its CAN transceiver has failed, or the network wiring between it and the reporting module is compromised, not that a specific hybrid component has failed.

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

Symptoms you may notice

  • Illumination of the check engine light, often accompanied by a hybrid system warning message on the dash
  • The vehicle may enter a reduced-power or limp mode and refuse to engage the hybrid drive system
  • Intermittent stalling or a no-start condition if the hybrid controller is completely offline
  • Loss of hybrid battery state-of-charge display or other hybrid-specific gauges on the instrument cluster
  • Multiple unrelated warning lights (ABS, traction control, power steering) if the hybrid controller shares a bus segment with those modules
  • Often no symptoms besides the warning light when the fault is a stored history code from a brief communication dropout

Common causes, most likely first

  1. Damaged or corroded wiring in the CAN bus circuit between the hybrid vehicle control module and the ECM, including chafed harnesses or pushed terminals
  2. Failed hybrid vehicle control module, often due to internal power supply or CAN transceiver failure
  3. Blown fuse or poor ground connection supplying power to the hybrid control module
  4. CAN bus termination resistor fault or a shorted CAN line on the network segment shared with the hybrid controller
  5. Low 12-volt battery voltage or a failing charging system causing modules to drop offline intermittently
  6. Aftermarket electronic devices improperly tapped into the CAN bus, disrupting communication
  7. Water intrusion into a connector or module housing in the hybrid controller circuit

How to diagnose and fix it

  1. Verify battery voltage and charging system output, then clear the code and test-drive to see if U0293 returns immediately or only intermittently
  2. Inspect the hybrid control module connectors for corrosion, pushed pins, or loose terminals and check the module's power and ground circuits with a multimeter
  3. Measure CAN bus resistance (should be about 60 ohms across the bus) and check for shorts to ground or power on the CAN high and CAN low wires
  4. Use a scan tool to confirm whether other modules can communicate with the hybrid controller and perform a network integrity test if the tool supports it
  5. Check for technical service bulletins (TSBs) or software updates for the hybrid control module that address communication dropouts
  6. If wiring and power are good, substitute a known-good hybrid control module or perform a module relearn/programming procedure as required
  7. After repair, clear all codes, perform a full drive cycle including hybrid system activation, and verify no communication codes return

What U0293 does not always mean

  • U0293 is frequently stored as a history code after a brief voltage dip during engine cranking, and it may never return once the battery is healthy, so do not replace the hybrid controller on the first sighting.
  • A failed 12-volt battery is one of the most common root causes because hybrid control modules are sensitive to low voltage and will drop off the CAN bus during cranking, setting communication codes across multiple modules.
  • The code can be set by a fault in any module on the same CAN segment, not just the hybrid controller, so a failed ABS or body control module can indirectly cause U0293 if it disrupts bus traffic.
  • Aftermarket remote starters, alarm systems, or dash cameras tapped into the CAN wiring often introduce noise or impedance faults that mimic a failed hybrid controller.
  • A hybrid controller that communicates fine with a factory scan tool but sets U0293 only under certain conditions may have a firmware bug addressed by a software update rather than a hardware failure.

Can I keep driving with U0293?

Do not continue driving with U0293 active because the hybrid system may shut down or enter limp mode without warning, leaving you with reduced power or a stalled vehicle in traffic. Have the vehicle towed to a qualified repair facility if the hybrid controller is completely offline, and avoid clearing the code repeatedly to force the vehicle to move.

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.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage