Start-up Test

The ECM stores the intake air temperature from the previous ignition cycle. The ECM then compares the IAT from the previous ignition cycle to the start-up IAT on the next ignition cycle. If the ECM does not detect a difference between the previous ignition cycle IAT and the start-up IAT, this DTC sets. If the diagnostic does not immediately pass, a delay timer increments. If the delay timer exceeds a threshold, the Start-up test is complete and the ECM will perform the Idle/Cruise test.