U0102 to U0115: lost communication with a powertrain module

Another module stopped receiving messages from one of the modules that run the drivetrain, such as the transfer case, the throttle actuator, the fuel pump, the glow plugs, a hybrid drive motor or battery, or a second engine computer.

SeverityHighCarrying on can cause expensive damage, so deal with it now.

Can you keep driving?Only as far as the workshop

What does U0102 mean?

Many cars split the work of the drivetrain across several modules: a separate one for the transfer case or the four-wheel-drive clutch, for the injectors or the fuel pump, for the glow plugs on a diesel, for the drive motor and battery on a hybrid. They report to the engine computer over the network. When one goes quiet for too long, the modules expecting it store a code naming it. What happens next depends on that module: some faults only switch off a feature, others limit power or stop the engine.

What causes U0102?

  1. A blown fuse or a failed relay feeding the module that went silent
  2. A module mounted low or under the car, where water and road salt reach its connector
  3. Damaged network wiring between that module and the rest of the car
  4. A weak battery or a loose ground connection
  5. A failed drivetrain module

What to check first for U0102

  • Read which module the code names and find where it is mounted on this car
  • Check the fuse and power feed to that module with the ignition on
  • Inspect its connector for water, salt and green corrosion
  • Check whether the named module answers a scan tool at all

Can you drive with U0102?

Drive only to a workshop, and only if the car drives normally. If the silent module is the throttle actuator, the fuel pump or the hybrid system, the car can lose power or stop; have it towed if it already has.

In states with an OBD-II emissions inspection, a car with the check engine light on fails the test until the fault is fixed.

Codes on this page

14
  • U0102Lost Communication with Transfer Case Control Module
  • U0103Lost Communication With Gear Shift Module
  • U0104Lost Communication With Cruise Control Module
  • U0105Lost Communication With Fuel Injector Control Module
  • U0106Lost Communication With Glow Plug Control Module
  • U0107Lost Communication With Throttle Actuator Control Module
  • U0108Lost Communication With Alternative Fuel Control Module
  • U0109Lost Communication With Fuel Pump Control Module
  • U0110Lost Communication With Drive Motor Control Module
  • U0111Lost Communication With Battery Energy Control Module "A"
  • U0112Lost Communication With Battery Energy Control Module "B"
  • U0113Lost Communication With Emissions Critical Control Information
  • U0114Lost Communication With Four-Wheel Drive Clutch Control Module
  • U0115Lost Communication With ECM/PCM "B"

Checked on · Rafael Soares

These are the generic meanings every manufacturer shares. Each brand adds its own detail, so your car's handbook, its service information and a qualified mechanic have the last word. OdoKeep has no connection with any manufacturer, and the app does not read codes from the car.

Write the code into the car's history

Log the code in OdoKeep as an OBD scan when a scanner or the workshop gives you one, then the repair and what it cost, and keep the maintenance that prevents it on a plan with reminders. The app keeps the record; it does not read the car.

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