1999 Mercury Mountaineer fuel pump

3. The fuel cap may not have been properly installed and securely
tightened.
These temporary malfunctions can be corrected by filling the fuel tank
with good quality fuel and/or properly installing and securely tightening
the gas cap. After three driving cycles without these or any other
temporary malfunctions present, theCheck Enginelight should turn off.
(A driving cycle consists of a cold engine startup followed by mixed
city/highway driving.) No additional vehicle service is required.
If theCheck Enginelight remains on, have your vehicle serviced at the
first available opportunity.
Light is blinking:
Engine misfire is occurring which could damage your catalytic converter.
You should drive in a moderate fashion (avoid heavy acceleration and
deceleration) and have your vehicle serviced at the first available
opportunity.
Under engine misfire conditions, excessive exhaust temperatures
could damage the catalytic converter, the fuel system, interior
floor coverings or other vehicle components, possibly causing a fire.
Fuel reset
Illuminates when the ignition is
turned to the ON position and the
fuel pump shut-off switch has been
triggered. For more information,
refer toFuel pump shut-off switch
in theRoadside emergencieschapter.
Air bag readiness
Momentarily illuminates when the
ignition is turned ON. If the light
fails to illuminate, continues to flash
or remains on, have the system
serviced immediately.
FUEL
RESET
Instrumentation
7

HAZARD FLASHER
Use only in an emergency to warn traffic of vehicle breakdown,
approaching danger, etc. The hazard flashers can be operated when the
ignition is off.
²The hazard lights control is
located on top of the steering
column.
²Depress hazard lights control to
activate all hazard flashers
simultaneously.
²Depress control again to turn the
flashers off.
FUEL PUMP SHUT-OFF SWITCH
After a collision, if the engine cranks but does not start, the fuel pump
shut-off switch may have been activated. The ªFuel Resetº indicator light
will illuminate in the instrument cluster. The shut-off switch is a device
intended to stop the electric fuel pump when your vehicle has been
involved in a substantial jolt.
1. Turn the ignition to the OFF position.
2. Check the fuel system for leaks.
3. If no fuel leak is apparent, reset the fuel pump shut-off switch by
pushing in the reset button.
4. Turn the ignition to the ON position. Pause for a few seconds and
return the key to the OFF position.
5. Make a further check for leaks in the fuel system.
Roadside emergencies
169

The fuel pump shut-off switch is
located in the passenger's foot well,
behind the kick panel.
FUSES AND RELAYS
Fuses
If electrical components in the
vehicle are not working, a fuse may
have blown. Blown fuses are
identified by a broken wire within
the fuse. Check the appropriate
fuses before replacing any electrical
components.
Always replace a fuse with one that has the specified amperage
rating. Using a fuse with a higher amperage rating can cause
severe wire damage and could start a fire.
15
Roadside emergencies
170

Fuse/Relay
LocationFuse Amp
RatingDescription
3 30A* Heated Backlight
4 15A* Fog Lamps and Daytime Running Lamps
5 Ð Not Used
6 10A* Powertrain Control Module
7 30A* 4 Wheel Anti-Lock System (4WABS) Module
8 15A* Rear Wiper Motor
9 20A* Fuel Pump Relay and RAP Module
10 15A* Horn Relay
11 15A* Parklamps Relay and Mainlight Switch
12 30A* Mainlight Switch and Multifunction Switch
13 15A* Heated Oxygen Sensor, EGR Vacuum
Regulator, EVR Solenoid, Camshaft Position
(CMP) Sensor, Canister Vent Solenoid
14 30A* Generator/Voltage Regulator
15 Ð Not Used
1 -- Wiper Park Relay
2 -- A/C Relay
3 -- Wiper High/Low Relay
4 -- PCM Power Relay
5 -- Fuel Pump Relay
6 -- Starter Relay
7 -- Horn Relay
8 -- Rear Wiper Down Relay
9 -- Blower Motor Relay
10 -- Rear Wiper Up Relay
1 -- Not Used
1 -- Not Used
2 -- Electronic Engine Controls Diode
* Mini Fuses ** Maxi Fuses
15.0L Engines Only
Roadside emergencies
177

Running out of fuel
Avoid running out fuel because this situation may have an adverse affect
on powertrain components.
If you have run out of fuel:
²You may need to crank the engine several times before the system
starts to pump fuel from the tank to the engine.
²Your ªCheck Engineº light may come on. For more information on the
ªCheck Engineº light, refer to theInstrumentationchapter.
Fuel Filler Cap
Your fuel tank filler cap has an indexed design with a one-eighth turn
on/off feature.
When fueling your vehicle:
1. Turn the engine off.
2. Carefully turn the filler cap counterclockwise 1/8 of a turn until it
stops.
3. Pull to remove the cap from the fuel filler pipe.
4. To install the cap, align the tabs on the cap with the notches on the
filler pipe.
5. Turn the filler cap clockwise 1/8 of a turn until it stops.
If the ªService Engine Soon/Check Engine ª indicator comes on and stays
on when you start the engine, the fuel filler cap may not be properly
installed. Turn off the engine, remove the fuel filler cap and reinstall it
being careful to align the cap properly.
If you must replace the fuel filler cap, replace it with a genuine
Ford or Motorcraft part. The customer warranty may be void for
any damage to the fuel tank or fuel system if a genuine Ford or
Motorcraft fuel filler cap is not used.
The fuel system may be under pressure. If the fuel filler cap is
venting vapor or if you hear a hissing sound, wait until it stops
before completely removing the fuel filler cap. Otherwise, fuel may
spray out and injure you or others.
Maintenance and care
216

Filling the tank
For consistent results:
²Use the same filling rate setting (low Ð medium Ð high) each time
the tank is filled.
²Allow three automatic click-offs when filling.
²Always use the recommended octane rating of a known quality
gasoline, preferably a national brand.
²Use the same side of the same pump and have the vehicle facing the
same direction each time you fill up.
²Have the vehicle loading and distribution the same every time.
Your results will be most accurate if your filling method is consistent.
Calculating fuel economy
1. Fill the fuel tank completely and record the initial odometer reading.
2. Each time you fill the tank, record the amount of fuel added (in liters
or gallons).
3. After at least three to five tank fill-ups, fill the fuel tank and record
the current kilometer (mileage) reading.
4. Follow one of the simple calculations in order to determine fuel
economy:
Multiply liters used by 100, then divide by total kilometers
traveled.
Divide total miles traveled by total gallons used.
Keep a record for at least one month and record the type of driving (city
or highway). This will provide an accurate estimate of the vehicle's fuel
economy. Additionally, keeping records during summer and winter will
show how temperature impacts fuel economy. In general, lower
temperatures give lower fuel economy.
Driving style Ð good driving and fuel economy habits
Give consideration to the lists that follow and you may be able to change
a number of variables and improve your fuel economy.
Maintenance and care
218