S15/T15 4WD P/U V6-173 2.8L (1985)
Engine Control Module: Description and Operation
Modes of Operation
After Break-In Adaptive Functions - "E" Cell
The ``E'' cell controls voltage at ECM terminal 15. For the first 25,000 miles of vehicle operation, voltage is nearly zero. The ``E'' cell then causes
voltage to rise to approximately 5 volts. This provides a different control value for some systems.
Trouble Code Memory
The ECM is capable of sensing certain system malfunctions, storing data related to these malfunctions in the trouble code memory and alerting the
operator of the malfunctions through the instrument panel mounted "Check Engine" lamp. If a system malfunction occurs while the engine is running, the
``Check Engine'' lamp will light and a trouble code will be stored in the ECM memory. The lamp will remain on with the engine running until
malfunction is corrected. If the malfunction is intermittent, the lamp will go out but the code will remain stored in the trouble code memory.