U0141 on 2013-2015 Mitsubishi Lancer Evolution: ETACS Communication Loss Fixes

What's Unique About the 2013-2015 Mitsubishi LANCER EVOLUTION

The Lancer Evolution X platform, along with its Lancer and Outlander siblings, is known for issues with the ETACS-ECU. Mitsubishi issued a safety recall (NHTSA Campaign ID: 14V569000, Mitsubishi SR-15-002) for some 2009-2010 models due to internal manufacturing defects in the ETACS-ECU that caused high electrical resistance. This defect could lead to voltage instability and the failure of headlights and wipers. This history means that a U0141 code on an Evo X is highly likely to be a genuine failure of the ETACS-ECU module itself, rather than a more common wiring or fuse issue seen on other vehicles.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Generation note: This issue is prevalent across the entire Lancer platform from 2008-2017, including the base Lancer, Ralliart, and Evolution models, as well as the related Outlander and Outlander Sport. A specific safety recall, SR-15-002, targeted 2009-2010 models for this ETACS failure.

Symptoms You May Notice

• Multiple random warning lights on the dashboard (SRS, ABS, etc.)
• "Service AWD System" message on the display
• Headlights, taillights, or turn signals not working or working erratically
• Windshield wipers not functioning
• Power windows, door locks, or keyless entry failing
• Climate control (A/C and heat) system not working
• Instrument cluster gauges freezing or going blank
• Vehicle may not start (no-crank or crank-no-start condition)

Most Likely Causes

1. Failed ETACS-ECU (Body Control Module) 🔴 High Probability This module is a known failure point on the Lancer platform, with a history of recalls (SR-15-002) and TSBs for internal defects causing voltage instability and component failure. Water intrusion into the driver's footwell from a leaky cowl or clogged sunroof drain tubes can also cause corrosion 🎬 Watch: How to unclog sunroof drains to prevent water damage and failure.
   How to confirm: Use a professional scan tool (like a M.U.T.-III) to attempt direct communication with the ETACS-ECU. If the module does not respond but has proper power and ground at its connectors, it has failed internally. The ETACS-ECU is integrated with the interior fuse box in the driver's side footwell.
   Typical fix: Replace the ETACS-ECU and program the new unit to the vehicle's VIN and specific configuration using a Mitsubishi-specific scan tool. This is typically a dealer or specialist repair. 🎬 See a technician diagnose and repair a faulty ETACS unit A forum user on mitsubishiforum.com noted a dealer quote of around $2,000 for this repair on a 2014 Outlander.
   Est. part cost: $275-$450
2. CAN Bus Wiring or Connector Issue 🟡 Medium Probability The ETACS-ECU is located in the driver's side footwell, making its connectors susceptible to corrosion from water entry (e.g., from wet shoes or a water leak).
   How to confirm: Visually inspect the wiring harnesses and connectors at the ETACS-ECU for any signs of damage, corrosion, or loose pins. A multimeter can be used to check for proper resistance between the CAN High (Pin 6) and CAN Low (Pin 14) wires at the OBD-II port; it should be approximately 60 ohms with the battery disconnected.
   Typical fix: Repair the damaged section of wiring or clean/replace the corroded connector. This can be a complex task requiring wiring diagrams.
   Est. part cost: $5-$50
3. Poor Power or Ground to ETACS-ECU ⚪ Low Probability
   How to confirm: Check all fuses related to the BCM/ETACS, particularly the IOD (Ignition-Off Draw) fuse, which can sometimes become unseated. Use a multimeter to verify that the ETACS-ECU is receiving proper battery voltage (10V-16.5V) and has a solid ground connection (resistance to ground should be less than 2 Ohms). A known ground point for the ETACS is G12, located under the front passenger's seat, but also check the ground circuit at the ETACS connector itself (e.g., D-419, pin 3).
   Typical fix: Replace blown fuses, clean corroded ground points, or repair the faulty power/ground wire.
   Est. part cost: $1-$20

Rare But Worth Checking

• Low Battery Voltage: A weak or dying battery can cause low voltage conditions that disrupt communication between modules, triggering a U0141 code. Always verify the battery and charging system are healthy (voltage above 12.4V) before proceeding with more complex diagnostics.

Diagnosis Steps

1. Check and verify battery voltage is above 12.4V and the charging system is working correctly.
2. Connect a professional scan tool (ideally a Mitsubishi M.U.T.-III) capable of reading all vehicle modules.
3. Attempt to communicate directly with the ETACS-ECU (Body Control Module). If it fails to respond, proceed to the next steps.
4. Inspect all fuses related to the ETACS-ECU and Body Control systems, particularly the IOD (Ignition-Off Draw) fuse located in the engine bay fuse box.
5. Locate the ETACS-ECU, which is integrated into the interior fuse panel in the driver's side footwell, and visually inspect its connectors and nearby wiring for corrosion, moisture, or physical damage.
6. With the key on, use a multimeter to verify the ETACS-ECU is receiving battery voltage on its power pins (e.g., ~12V at connector C-307 pin 2) and has a good ground connection on its ground pins (e.g., <2 Ohms at connector C-315 pin 17).
7. With the battery disconnected, measure the resistance between Pin 6 (CAN-H) and Pin 14 (CAN-L) on the OBD-II port. A healthy CAN bus will show approximately 60 Ohms.
8. If power and ground are good and the CAN bus resistance is correct, but the module is unresponsive, the ETACS-ECU has most likely failed and requires replacement and programming.

Parts You'll Likely Need

• ETACS-ECU (Body Control Module) (OEM #8637A826) — This is the most common point of failure for a U0141 code on this platform due to a history of internal defects. This specific part number is listed for the Lancer, Lancer Ralliart, and Lancer Evolution.
  Trusted brands: Mitsubishi Genuine OEM
  OEM price range: $275-$450
  Aftermarket price range: $150-$300 (Used/Remanufactured, but requires special programming)

Related Codes That Often Appear With This One

• U0155 — Lost Communication With Instrument Panel Cluster (IPC) Control Module. A network-wide issue caused by the failing ETACS-ECU can disrupt communication with other modules like the instrument cluster.
• U0100 — Lost Communication With ECM/PCM 'A'. If the CAN bus network is compromised, communication with the main engine computer can also be lost.
• U0101 — Lost Communication with TCM. On models with the TC-SST automatic transmission, a CAN bus failure can also take the transmission control module offline.
• U0121 — Lost Communication With Anti-Lock Brake System (ABS) Control Module. This is another common code seen alongside U0141 when the ETACS fails, as seen in owner forum posts.

Technical Service Bulletins (TSBs) & Recalls

• TSB-19-54-008: Updates diagnostics for ETACS-ECU CAN timeout with DTC U0141 in the Chassis Electrical section for a wide range of Mitsubishi vehicles, including the 2008-2015 Lancer Evolution.
• TSB-19-52B-005: Updates diagnostics for ETACS-ECU CAN timeout with DTC U0141 in the Supplemental Restraint System (SRS) section.
• TSB-19-42B-003: Updates diagnostics for ETACS-ECU CAN timeout with DTC U0141 in the Body section.
• SR-15-002 (NHTSA 14V569000): Safety recall campaign for 2009-2010 Lancer, Lancer Evolution, and Outlander models to inspect and replace defective ETACS-ECU units that could cause loss of headlights and wipers.

Platform-Specific Known Issues

• Mitsubishi issued Technical Service Bulletins TSB-19-54-008, TSB-19-52B-005, and TSB-19-42B-003 to update dealer diagnostic procedures for ETACS-ECU CAN timeout issues related to DTC U0141, indicating it was a common concern across many models and systems.
• A safety recall was issued for some earlier Lancer models (NHTSA 14V569000 / Mitsubishi SR-15-002) for internal ETACS-ECU defects that could cause headlight and wiper failure, which is directly related to the U0141 code.
• Owner experiences on forums like EvolutionM.net frequently cite water damage from clogged sunroof drains or other leaks as a cause of ETACS-ECU corrosion and failure.

Mechanic-Grade Diagnostic Values

• CAN Bus Resistance (at OBD-II Port) — expected: ~60 Ω. Failure: A reading of ~120 Ω indicates an open circuit or faulty terminating resistor. A reading near 0 Ω indicates a short between CAN-H and CAN-L.
• ETACS-ECU Operating Voltage — expected: 10V to 16.5V. Failure: Voltage below 10V can cause the module to stop communicating and set a U0141 code.
• ETACS-ECU Ground Circuit Resistance — expected: < 2.0 Ω. Failure: Higher resistance indicates a poor ground connection, which can cause intermittent communication issues.
• CAN High Voltage (to ground, key on) — expected: ~2.6V (fluctuating between 2.5V and 3.5V). Failure: A static voltage or one outside this range indicates a bus fault.
• CAN Low Voltage (to ground, key on) — expected: ~2.4V (fluctuating between 2.5V and 1.5V). Failure: A static voltage or one outside this range indicates a bus fault.
• Communication Timeout Threshold — expected: Signal must be received continuously. Failure: If a signal from the ETACS-ECU is not received for 2.5 to 4 seconds, other modules will log DTC U0141.

Scan Tool Commands That Help

• Mitsubishi M.U.T.-III: CAN bus diagnosis — This is the first diagnostic step to check the overall health of the network and confirm which modules are offline, verifying the ETACS-ECU is the source of the problem.
• Mitsubishi M.U.T.-III: Coding Information & Copy — This is a critical step *before* removing the old ETACS-ECU. It saves the vehicle's unique configuration and customization data, which is required to program the new module.
• Mitsubishi M.U.T.-III: Variant Coding / On Vehicle Coding — This function is mandatory after installing a new ETACS-ECU. It writes the vehicle's VIN and saved configuration file to the new module, making it operational.
• ETACS Decoder / MMCodingWriter: Read/Write ETACS Variant and Custom Coding — These are powerful aftermarket software tools used with a J2534 adapter that provide an alternative to the dealer's M.U.T.-III for saving, editing, and writing the ETACS configuration, essential for advanced DIY or independent shop repair.

Wiring & Ground Locations

• ETACS-ECU — Integrated with and clipped to the back of the interior fuse box (Junction Block) in the driver's side footwell.. This is the module that has lost communication. Physical access is required to check its connectors (e.g., C-301, D-419) for power, ground, and CAN signals.
• Sunroof Drain Tubes — Run down the inside of the A-pillars from the sunroof cassette.. These tubes are known to clog, causing rainwater to overflow and drip directly onto the ETACS-ECU and its connectors, leading to corrosion and failure.
• Joint Connector C-06 (CAN1) — Part of the CAN bus wiring harness, serves as a junction point.. A loose, corroded, or damaged terminal in this central connector can disrupt the entire CAN bus network, causing communication loss with the ETACS.
• Ground Point G12 — Under the front passenger's seat.. This is a known chassis ground point. While not the only ground, ensuring it is clean and tight is part of a thorough electrical diagnosis.

Real Owner Repair Stories

• EvolutionM forum user (2011 Mitsubishi Lancer Ralliart) — Multiple communication codes including U0141, 'Service AWD System' warning, non-functional accessories.
  ❌ Tried (didn't work) Checking fuses, Testing battery
  ✅ What actually fixed it The ETACS-ECU was found to have significant corrosion from a water leak originating from a clogged sunroof drain. Replacing the ETACS-ECU and programming the new unit with the vehicle's original coding resolved all issues.
• MHH AUTO forum post (2018 Mitsubishi Outlander 4WD) — Door locks not working, U0141 stored.
  ❌ Tried (didn't work) Installing a used ETACS with the same part number from a 2WD model. The module was not plug-and-play.
  ✅ What actually fixed it The used ETACS module had to be re-initialized and have the correct VIN written to it using the M.U.T.-III SE scan tool. This highlights that even a correct part number requires programming.

OEM Part Supersession History

• 8637A826 → N/A — This is the specified part number for the Lancer, Lancer Ralliart, and Lancer Evolution.
  Heads up: Do not use ETACS-ECUs from other models like the Outlander (8637A824) or Lancer Sportback (8637A825), even if they appear physically similar. They are programmed for different vehicle lines and will not function correctly.

Model Year Variations Within This Range

• 2008-2017: A Technical Service Bulletin (TSB-18-54-003) was issued for a dome light flicker issue caused by ETACS logic. The fix was to reprogram the ETACS with updated software. While not a direct fix for U0141, it shows that ETACS software was revised during the Lancer's production run and that software updates are possible.