Diagnostic Aids
Suction from shop exhaust hose can alter backpressure and may alter operation of EGR valve during in-stall testing. DTC can set if exhaust system is leaking. Check vacuum lines for leaks and proper routing.
Using FREEZE FRAME and/or FAILURE RECORDS data mode may aid in locating an intermittent condition. If DTC cannot be duplicated, information included in the FREEZE FRAME and/or FAILURE RECORDS data can be useful in determining how many miles since the DTC set. The FAIL COUNTER and PASS COUNTER can also be used to determine how many ignition cycles the diagnostic reported a pass or a fail condition. To isolate when DTC failed, operate vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature, etc.).