D50/Power Ram 50 V6-181 3.0L SOHC (1991)
Check Engine Lamp: Testing and Inspection
The malfunction indicator light will come on when the Electronic Control Unit (ECU) detects an irregularity in one or more of the following
monitored circuits: the ECU, injector, fuel pump, or in the oxygen, air flow, intake air temperature, throttle position, engine coolant temperature, crank
angle, top dead center or barometric pressure sensor circuits.
When an irregular signal returns to normal or is repaired and the ECU judges that it has returned to normal, the malfunction indicator light will turn
OFF. When the ignition switch is turned OFF then malfunction indicator light will turn off until such time as the irregular signal is detected again. The
ECU will set and retain a fault code corresponding to the detected irregularity for 50-100 starts after the irregularity was detected unless the battery or
ECU is disconnected.
