Diagnostic Aids
WARNING: This page is about a different car, the 2002 Isuzu Trooper. However, it is still accessible from the selected car via links, so may be relevant.
Excessive carbon buildup on EGR valve shaft may cause valve to hang up or fail to seat properly. An intermittent problem can be caused by misrouted harness, rubbed-through wire insulation or broken wire inside insulation. Monitor EGR actual position display while moving EGR connections and related harnesses. Change in scan tool display will indicate area of fault. Reviewing scan tool FAILURE RECORDS data can be useful in determining mileage and frequency of DTC occurrence.