EGR Valve
- Check that EGR is securely mounted to engine. Repair as necessary. Go to next step.
- With engine at normal operating temperature. Place transmission in park or neutral. Using a scan tool command EGR ON 50%. If engine stumbles, stalls, runs rough and looses RPMs, EGR is operating normally. If none of these conditions were found during EGR ON 50%, go to next step.
- Turn engine off. Turn ignition on. Using a test light, check EGR ignition feed of EGR connector. If test light illuminates, go to next step. If test light does not illuminate, repair EGR harness ignition feed.
- Remove EGR valve. Visually and physically inspect EGR valve pintle, passages through EGR and port going to EGR valve for excessive build up of carbon or other deposits. Clean, repair or replace as necessary. If EGR valve is in good condition, go to next step.
- Ground EGR valve to battery negative terminal. Using scan tool command EGR ON and observe EGR valve pintle for movement. If movement is not seen, go to Diagnostic Trouble Code chart DTC P1406. If EGR valve movement is observed while EGR command is given, go to next step.
- Remove EGR inlet and outlet pipes from intake and exhaust manifolds. Visually inspect manifold ports, inlet and outlet pipes for blockage or restriction caused by excessive deposits or other damage. Clean, replace or repair any or all affected components as necessary. If components are all clean and unrestricted, EGR system is operating as designed.