Sable V6-232 3.8L (1988)
Malfunction Indicator Lamp: Technical Service Bulletins
Malfunction Indicator Light - Explanation
LAMP - "MALFUNCTION INDICATOR LIGHT"
Article No.
(MIL) - SERVICE INFORMATION
88-5-7
FORD:
1988 ALL CAR LINES
LINCOLN-MERCURY: 1988 ALL CAR LINES
MERKUR:
1988 ALL CAR LINES
LIGHT TRUCK:
1988 ALL LIGHT TRUCK LINES
ISSUE:
The Malfunction Indicator Light (MIL) is a new feature that has been added to 1988 vehicles. Vehicle applications are on page 18 of this
TSB. The MIL's (Check Engine) is active when the engine system requires service. An explanation of how and when the Malfunction
Indicator Light (MIL) operates may need to be explained to some vehicle owners.
ACTION:
Use the following service information to explain the operation of the Malfunction Indicator Light (MIL) to resolve customer concerns.
NOTE:
It is not necessary to immediately turn off the engine or have the vehicle towed when the "Check Engine" (MIL) light comes on.
Vehicles Equipped with EEC IV
The CHECK ENGINE light will come on while engine is operating in Failure Mode Effects Management (FMEM) or Hardware Limited Operation
Strategy (HLOS) modes. The light will stay on as long as the fault causing it is present.
In FMEM mode, the computer is receiving a sensor signal that is outside the limits set by the calibration strategy. In this mode, the computer uses an
alternate strategy to maintain reasonable vehicle operation in spite of the fault. Page 18 of this TSB lists the system faults which will turn on the CHECK
ENGINE light in this mode. The error code associated with this system fault is stored in Keep Alive Memory (KAM). If the fault is no longer present,
the light will turn off and vehicle will return to normal vehicle strategy. The error code stored when the light was on was not erased. This code is one of
the continuous error codes and can be accessed by running the KOEO self-test.
HLOS mode is used when the system fault(s) is too extreme for the FMEM mode to handle. In HLOS mode, all software operations have stopped and the
computer is running on hardware control only. The default strategy for this mode has a minimal calibration just to allow the vehicle to operate until it can
be serviced.
