CAN network

U0114 — Lost Communication with Four-Wheel Drive Clutch Control Module

Severity: medium Drive with care, to a shop

What U0114 means

U0114 means another control unit on the CAN network has stopped receiving messages from the four-wheel drive (AWD) clutch control module. This module normally runs the clutch that sends torque to the rear axle and constantly exchanges data with the engine, ABS and instrument cluster. When communication is lost, the system disables AWD as a safety precaution.

Symptoms

  • AWD or 4WD warning light comes on
  • All-wheel drive does not engage and the car runs on one axle
  • Reduced traction in snow, ice and mud
  • ABS or stability control light may also appear
  • Fault appears intermittently, sometimes after startup
  • Other modules log network communication codes

Possible causes

  1. Failed AWD clutch control module
  2. Open, corroded or shorted CAN bus wiring
  3. Damaged or wet module connector (often mounted low near the transfer case or rear axle)
  4. Low system voltage, weak battery or poor ground
  5. Blown fuse or faulty power relay for the module
  6. Software glitch or another module disrupting the bus

How to diagnose

  1. Scan all systems, including AWD, and note any other U-codes for network faults
  2. Test battery and charging voltage, and check battery terminals and grounds for cleanliness and tightness
  3. Check the fuses and relays that power the clutch module using the wiring diagram
  4. Inspect the module connector and harness for moisture, corrosion and chafing
  5. Test CAN-H and CAN-L for continuity, resistance, and shorts to ground or power
  6. Confirm whether the scan tool can see and talk to the module
  7. Measure power and ground at the module connector with a multimeter
  8. Look for software updates or technical service bulletins for your model

Common fixes

  • Clean or replace corroded connectors and repair damaged wiring
  • Replace the blown fuse or faulty relay
  • Repair the ground and power supply, and replace the battery if weak
  • Update the module software, or replace and program the module if confirmed faulty
  • Clear the code and road test to verify the repair

Questions and answers

Can I drive with a U0114 code?

Usually yes, but AWD is probably disabled. Drive carefully, especially on slippery roads, and don't put off diagnosis.

What most often causes U0114?

Wiring and connector problems at the module, low voltage, or a failed clutch control module are the usual causes. Start by checking the battery, fuses and connector.

Can I just clear the U0114 code?

You can clear it with a scan tool, but it will return if the cause remains. Find the source of the lost communication 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.