General
After carrying out repairs it may be necessary to check that the fault really has been remedied. One way of doing this is to check that the engine control module (ECM) has carried out a self diagnostic for the function/component that has been repaired, and that the diagnostic trouble code (DTC) has not recurred.
Verifying repairs is only intended as an aid if uncertain whether the fault persists or not. If an obvious fault is detected during fault-tracing it is not necessary to verify the repair.