Civic Hatchback L4-1493cc 1.5L SOHC (D15B1) TBI (1990)
2. Back-Up Function:
When an abnormality occurs in the ECU itself, the injectors are controlled by a back-up circuit independent of the system in order to permit normal
driving.
3. Self-Diagnosis Function:
When an abnormality occurs in a signal from a sensor, the ECU lights the "CHECK ENGINE" warning light, stores the failure code in erasable
memory and indicates the code with an LED on the ECU anytime the ignition is ON. When the ignition is initially turned on, the ECU supplies
ground for the "CHECK ENGINE" warning light for about 2 seconds.