B150 1/2 Ton Van V6-239 3.9L (1989)
Check Engine Lamp: Description and Operation
The check engine light will be illuminated if the SMEC receives an incorrect or no signal from certain sensors or emission related systems on
California vehicles. This warns the driver that the SMEC has gone into a limp-in mode to keep the system operational.
Each time the ignition is turned on the check engine light will illuminate for 3 seconds as a bulb test.
