DTC Info For OBD II Vehicles
Engine DTCsWhen the ECM/PCM receives an abnormal signal from an engine sensor, the MIL stays on when you turn on the ignition switch. If the ECM/PCM receives a signal indicating a misfire that's strong enough to cause catalytic converter damage, it stores a misfire DTC. When a misfire DTC is stored, the MIL blinks when you turn on the ignition switch.
Transmission DTCs
When the PCM receives an abnormal input or output from the transmission, the D4 indicator in the gauge assembly flashes until you turn off the ignition switch. (Not all input/output problems cause the indicator to flash.) When you restart the engine, the MIL (malfunction indicator lamp) stays on, indicating that there's a stored DTC. The D4 indicator light will not flash again until another (or the same) transmission abnormality is detected.