Thunderbird V8-302 5.0L HO (1992)
Maintenance Required Lamp/Indicator: Description and Operation
Oil Change Interval Indicator Reset Switch Access Hole Location
PURPOSE
The Vehicle Maintenance Monitor (VMM) warns the driver of low oil level, low radiator coolant, low fuel, and low washer fluid conditions. It
also indicates when to change the engine oil.
OPERATION
The module lights all segments of the display for one second, blanks them for one second, then goes to normal operation when ignition key is
released to the RUN position. The oil change display turns off after fifteen minutes if the VMM module is not receiving a tachometer signal.
Low Oil Level
The low oil indicator illuminates when the engine oil is between 3/4 to 1 1/2 quarts low. To prevent false low indication, a five minute delay is
designed into the indicator circuit.
Low Coolant Level
The low coolant indicator illuminates when the coolant level drops one inch below the "Full Cold" mark on the side of the recovery reservoir.
The indicator remains illuminated until the coolant is filled to the "Full Hot" mark, and the ignition is cycled OFF and back ON.
Low Fuel Level
The low fuel indicator uses input from the fuel tank sender to illuminate when the fuel level reaches approximately 1/8 tank capacity, and
remains there for sixty seconds.
Low Washer Fluid Level
The low washer fluid indicator illuminates when the washer fluid capacity drops to approximately 1/3 of bottle capacity for sixty seconds.
Oil Change Indication
The VMM monitors engine oil temperature and tachometer signals to measure quality of oil, and indicate when engine oil should be changed.
The green bar under "OK" on the display is lit for 0 to 89% of the oil change cycle. "SOON" is lit for 90 to 99% of the cycle, and "NOW" is lit
and flashes after 100 to 115% of the cycle. The oil change indicator must be reset after the oil is changed, whether or not it is illuminated at the
time of service.