U0404Invalid Data Received From Gear Shift Control Module A
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Gear shift control module A is the electronic selector of shift-by-wire cars: lever, dial or buttons that report the chosen range as data. U0404 means its messages still arrive but the receiver, usually the transmission controller, rejects them. GM's 2025 ECM checks counter and protection fields of the selector's position-sensor and self-check signals, fails a signal after 4 errors in 10 or 8 in 18 checks; the code is Type B with two trips. FCA stored U0404 in the TCM of 2016 Durango and Grand Cherokee eight-speeds with MIL and a blinking M on shifter and cluster, cured by TCM software (21-011-16 Rev. A). Audi found U040400 in the gearbox unit of 2021 A6/A7 models with an intermittent selector lever fault message and no range selectable; the gateway J533 needed new software. U0103 means lost contact, U0304 a software conflict.
- What you may notice
- Selector fault message or flashing range indicator
- Range cannot be selected or vehicle stays in Park
- Check engine light
- Likely causes
- LikelySoftware of TCM or gateway (update available)
- PossiblePosition sensor or electronics in the selector delivering implausible values
- PossibleConnector or bus line at the selector loose or corroded
- RareGear shift module internally faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.