U040DInvalid Data Received From Turbocharger/Supercharger 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
- Turbocharger/supercharger control module A is in practice an electronic charger actuator that sets the vanes of a variable-geometry turbine or a wastegate on command and reports position and status back. U040D means those reports arrive but the engine controller judges them invalid. No manufacturer documents U040D publicly. The module is documented through its lost-contact code U010C: GM's 2017 small-diesel table expects its frames on a dedicated sensor bus, and FCA replaced the turbo actuator of 2015 Ram 2500/3500 trucks with the 6.7 L Cummins under a warranty extension when U010C came with boost codes (09-005-22). With invalid actuator data the boost loop cannot be closed with confidence, so the controller usually caps boost and torque; boost control is emission-relevant under CARB, so a MIL is likely. U040E is module B.
- What you may notice
- Check engine light
- Noticeably reduced power (limp mode)
- Boost pressure codes stored alongside
- Likely causes
- LikelyElectronics of the turbo actuator degraded by heat
- PossibleSticking vanes or linkage making the actuator report implausible positions
- PossibleConnector or sensor bus line at the actuator damaged
- 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: €150 – €1,800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.