LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mazda >> 2014 >> 3 SV, Automatic Trans >> Repair and Diagnosis >> Brakes >> Traction Control >> On-Board Diagnostic - Dynamic Stability Control System >> DTC U0402 00: Abnormal Message From Transmission/Transaxle >> Notes
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC U0402 00: Abnormal Message From Transmission/Transaxle: Notes

DTC U0402 00 DETECTION CONDITIONS AND POSSIBLE CAUSES (DYNAMIC STABILITY CONTROL)

DTC  U0402:00  Abnormal message from transmission/transaxle 
DETECTION CONDITION 
  • The DSC HU/CM received error signals from the transmission/transaxle for 1 s or more  with the ignition switched ON (engine off or on).
FAIL-SAFE FUNCTION 
  • Illuminates the TCS/DSC indicator light and smart city brake support (SCBS) indicator light (amber)*1 .
  • Tire pressure monitoring system warning light*1 illuminates after flashes.
  • Inhibits the TCS, DSC, hill launch assist (HLA), TPMS*1 , and smart city brake support (SCBS)*1 controls.

*1 : If equipped.
POSSIBLE CAUSE 
  • The transmission/transaxle could not send a normal signal temporarily. (DTCs are stored in the TCM.)
  • Transmission/transaxle malfunction
  • DSC HU/CM malfunction
SYSTEM WIRING DIAGRAM  Not applicable