Code on diagnostics p0401
Code on diagnostics p0401:
What is going on?
Exhaust Gas recirculation low flow detected means that: there is vacuum problem in the EGR system - between the combustion chamber, EGR valve (mechanical - blown up diaphragm or clogged airlets/hoses) , EGR Modulator Valve (mechanical - blown up diaphragm, dirty EG/air filter or clogged airlets/hoses) and Vacuum Switching Valve ((mechanical - blown up diaphragm or clogged airlets/hoses OR electrical - VSV not properly synchronizing with the ECM, for instance).
This causes the combustion chamber temperature to increase and produce Oxides of Nitrate (NOx) that is out of an acceptable emission range. This triggers the Malfunction Light (check engine light) to stay on (after a couple of driving cycles)!
Solution: Focus on EGR airways (hoses...) and organs (EGR valve, EGR Modulator, VSV), clean, check or replace the defected one. VSV seems to be criticale as it plays electrical & mechanical function. Once the repair is done, Clear the P0401 code using an OBII scanner.
Dec 21, 2008 |
1996 Lexus LX 450