Diagnostic Aids

Inspect VCM connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal to wire connection. Inspect wiring harness for damage. If connections and harness are okay, observe scan tool while wiggling related connectors and wiring harness. A change in display will indicate location of fault.

If EGR valve indicates signs of excessive heat, check exhaust system for blockage (i.e., plugged converter). If exhaust system is restricted, check for possible open injector cause by grounded driver circuit, injector stuck open or faulty VCM. If problem is not found, check oil for possible fuel contamination.