U0126 on Mitsubishi: How to Diagnose & Fix
Lost Communication With Steering Angle Sensor Module
1 Mitsubishi model · 1 documented issue · 1 critical
U0126 on Mitsubishi by model: symptoms, diagnosis and fix
Early Eclipse Cross models with Forward Collision Mitigation brake hard for objects that are not there. This is not just owner perception — NHTSA recall 18V620000 covers 2018-2019 Mitsubishi vehicles whose FCM-ECU software applies braking for longer than needed even after a pedestrian is no longer detected, with the stated consequence that drivers brake harder in response and increase rear-end collision risk. Companion recall 18V621000 covers a hydraulic unit ECU software defect that may prevent automatic emergency braking, ABS, electronic stability control and Brake Auto Hold from working properly. Owner complaints go beyond the recall scope: filings describe adaptive cruise control triggering FCM braking when cresting hills with nothing ahead, and repeated multi-warning-light events with hard braking recurring several times a year despite dealer repairs. The camera-and-radar fusion is sensitive to road crown, overhead signs and reflective surfaces, and the system's brake authority is high enough that a false trigger at highway speed is genuinely hazardous.
Common Symptoms
- Vehicle brakes hard with no object ahead
- False forward collision warning alarms at any speed
- Braking triggered when cresting a hill on adaptive cruise
- Multiple dashboard warning lights flash simultaneously
- FCM, ASC and ABS warning lights on together
- Automatic emergency braking or Brake Auto Hold inoperative
How to Fix
First, run the VIN against NHTSA recalls and have both 18V620000 (FCM-ECU reprogram, Mitsubishi reference SR-18-007) and 18V621000 (hydraulic unit ECU reprogram, reference SR-18-008) performed free of charge if not already applied. If phantom braking persists after the reflashes, the next step is a windshield-camera aim and calibration — a replaced or improperly calibrated windshield is a very common cause of false triggers, and the camera requires a targeted static or dynamic aiming procedure, not just a mount swap. Check the front radar sensor behind the lower grille for physical misalignment, ice packing or a bent bracket from minor parking contact. As a temporary measure the FCM system can be switched off from the vehicle settings menu before each drive, though it re-arms at every ignition cycle.
Sources for this issue (2)
U0126 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does U0126 mean on a Mitsubishi?
U0126 stands for "Lost Communication With Steering Angle Sensor Module." Sets when a module loses data-bus communication with the Steering Angle Sensor Module, which provides steering position to the stability system, and no longer receives its expected messages. On Mitsubishi it is documented across 1 model: Eclipse Cross.
What are the most common causes of U0126?
The most common causes of U0126 are: Open or shorted bus wiring to the steering angle sensor module, Corroded or loose connector (often in the clockspring circuit), Blown fuse / lost power or ground, Low battery voltage, Failed steering angle sensor module. The specific cause varies by vehicle.
How much does it cost to fix U0126 on a Mitsubishi?
Repair costs vary widely with the root cause and Mitsubishi model; each issue on this page carries its own estimate where one is published.
Looking for U0126 on a different make?
View U0126 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.