check engine light MITSUBISHI LANCER EVOLUTION IV 1998 User Guide

REAR AXLE – On-vehicle Service <Vehicles with AYC>27-32
Waveform Observation Points
SymptomProbable causeAction
Waveform amplitude is too small, or no
waveform.Defective speed sensorReplace sensor.
Waveform amplitude varies greatly. (No
problem ifthe smallest amplitude is 100
Excessive axle hub lateral and radial runoutReplace hub.
problem if the smallest amplitude is 100
mV or more)Poor AYC-ECU groundingRepair.
Noise on waveform or disturbed
waveform
Open-circuited sensorReplace sensor.
waveform
Open-circuited harnessRepair harness.
Improperly mounted speed sensorCorrect sensor installation.
Missing or collapsed rotor toothReplace rotor.
Caution
Since the speed sensor cable follows the movement of the front or rear suspension, it may be
open-circuited only when the vehicle is run on rough roads and not on ordinary road. The speed
sensor output voltage waveform should therefore be checked also by rocking the sensor harness
so that driving on rough roads may be simulated.
8. ACTION WHEN BATTERY RUNS OUT
When the engine is started using a booster cable where the
battery has completely run down and you attempt to start
the vehicle without waiting for the battery to recover a certain
charge, the engine can misfire and you just cannot start to
move it. In such cases, charge the battery sufficiently; or,
remove the AYC fusible link from the engine compartment
relay box to make AYC inactive before attempting to start
the vehicle. When the fusible link is removed, the AYC warning
lamp lights up. After the battery has been recharged, fit the
fusible link back again and start the engine to ensure that
the AYC warning lamp is off.AYC fusible link

CHASSIS ELECTRICAL – Headlamp54-35
Standard values:
Vertical direction25’ (22 mm) below hori-
zontal line (H)
Horizontal
directionLeft headlampParallel to direction of
vehicle travel
Right head-
lamp15’ (13 mm) leftward
from vertical line (V)
Caution:
(1) Perform aiming adjustments, one light at a time,
with the other headlamp disconnected so as not
to be lit unless circumstances compel otherwise.
When reconnecting the headlamps, be careful not
to upset their aim. Do not leave the headlamps
on for any longer than 3 minutes if their outer
lenses are covered with a surface covering
impervious to light.
(2) Do not mask the outer lenses by taping or in any
other way.
(3) Aiming adjustment must be completed with the
aiming adjustment screws turned in the tightening
direction.
INTENSITY MEASUREMENT
1. Position the tester so that its light sensor faces each
headlamp center to center at the appropriate distance
shown.
2. Maintain an engine speed of 2,000 r/minto keep the battery
in the charged condition.
3. Check that the high-beam headlamp intensity at the center
of the high intensity zone satisfies the limit value.
Limit: 15,000 cd or more per headlamp
Caution
(1) Perform intensity measurement, one headlamp at
a time, with the low-beam lamp and the other
headlamp disconnected from the battery unless
circumstances compel otherwise. Do not leave
the headlamps on for any longer than 3 minutes
if their outer lenses are covered with a surface
covering impervious to light.
(2) Do not mask the outer lens surfaces by taping
or in any other way.
HEADLAMP BULB REPLACEMENT
1. Disconnect the connector.
2. Remove the socket cover.
3. Unhook the spring which secures the bulb, and then
remove the bulb.
Caution
Do not touch the surface of the bulb with hands or
dirty gloves. If the surface does become dirty, clean
it with alcohol or thinner, and let it dry thoroughly
before installing.
<Left headlamp>
Lamp center
Vertical direction
Vertical direction High
intensity
zone
center
(optical
axis)
High
intensity
zone
center
(optical
axis)High intensity zone
High intensity zoneLamp center <Right headlamp>V
H
V
H
Screen type tester: 3 m Converging
lens type tester: 1 m
Spring