Verifying Repairs: Notes

Procedure for verifying repairs depends on scan tool functions and whether DTC is set by one-trip or two-trip fault detection logic. Two-trip fault detection logic requires fault be detected on 2 consecutive drive cycles, which each meet code set criteria, before DTC will set and MIL will illuminate. DTCs using one-trip fault detection logic set DTC the first time fault is detected. If fault is emissions related, ECM/PCM will also turn on MIL. Most DTCs use two-trip fault detection logic. To determine which logic is used to set DTC, see DTC INDEX  table. Then, go to appropriate repair verification procedure.