FixVault

On Board Diagnosis Logic

If the absence of EGR flow is detected by EGR temperature sensor under the condition that calls for EGR, a low-flow malfunction is diagnosed.

DTC DETECTING CONDITION AND POSSIBLE CAUSE

DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0400
0400
EGR function (Close) No EGR flow is detected under the condition that calls for EGR.
  • Harness or connectors (The EGR volume control valve circuit is open or shorted.)
  • EGR volume control valve stuck closed
  • Dead (Weak) battery
  • EGR passage clogged
  • EGR temperature sensor and circuit
  • Exhaust gas leaks