warning lights MITSUBISHI ECLIPSE 1991 Service Manual

possibility that there is trouble with ABS warning
light or with power to the light.probably blown.
MAIN FUSIBLE
LINK @
5-12BRAKES - Anti-lock Braking System TroubleshootingA ABS warning light does not light at all.
I_
[Explanation][Hint]When it does not
liuht ULI at all, there is a strongIf other warning lights do not light up either, fuse is
IGNITIONSWITCH (IG2)IGNITIONSWITCH (IGl)
10A +,
“2.I6
-1z
v,,14TO ABS
I
” IPOWERIs&h ICOMBINAT~~N
ABS ECU
IGND GNDGNDv v vI
-14AO596

BRAKES - Anti-lock Braking System Troubleshooting5-13With the ignition key in the “ON”
posi-Nol
tion, do other warning lights illuminate?
II
YesCheck fuse No. 11. If it is
blown, correct the cause of
the blown fuse and then
replace the fuse.
Does voltage between
har-NoThe harness between thenessconnector terminalcombination meter from
No. 14 and ground indicate) fuse No.1 1 is broken.
battery voltage?
II
Yes
Repair harness.Circuit in combination meter
is broken.Repair or replace
com-
* bination meter.
Turn the ignition switch OFF an
(check.
IIs the ABS warning light normal? (Check
for burned bulb.)
No L A&zed%rning light bulb -Are instrument panel wiring harness,
_Noengine compartment wiring harness,~ Connect connectors firmly.
(Check for pins pulled out or
bent, repair as needed.) body wiring harness and ABS wiring
harness connectors connected properly?drive circuits. Check and repair both

BRAKES - Anti-lock Braking System Troubleshooting549
E-lInput abnormality of wheel speed sensorI-[Explanation][Hint]The ABS ECU detects breaks in the wheel speed
In addition to a broken wire/short circuit in the wheelsensor wire. The warning light lights up if the wheel
speed sensor, also check whether the sensor gap isspeed sensor signal is not input (or short circuited)
too large, rotor teeth are missing, sensor harness
or if its output is low when starting to drive or while
wire is temporarily broken, or sensor harness and
driving.body connector are not properly inserted.
I IE-2Output abnormality of wheel speed sensorI
[Explanation]The warning light lights up when there is an
abnormality (other than broken wire or short circuit)
in the wheel speed sensor output signal while
driving.
[Hint]
The following can be considered as the cause of thewheel speed sensor output abnormality.
l Distortion of rotor, teeth missing
lLow frequency noise interference when sensor
harness wire is broken
l Noise interference in sensor signall When the sensor output signal is below the
standard value or when amplitude modulation is
over the standard value, using an oscilloscope tomeasure the wave shape of the wheel speed
sensor output signal is very effective.
l Loose wheel bearing
l Temporarily broken wire in sensor harness
l Sensor harness and body connector are not
properly inserted.
NOTE
If contact is poor, check the sensor cable by bendingand lightly stretching it.
SPEED SENSOR
FRONTREAR(LEFT SIDE) (RIGHT SIDE) (LEFT SIDE) (RIGHT SIDE)
Km
I-.IIGND
III24I
FRONT SIDE
I
ABSECU
REVERSE SIDE
SELF-DIAGNOSIS
CHECK CONNECTOR
14AO601

BRAKES - Anti-lock Braking System Troubleshooting5-g
E-3Abnormality of stop light switch circuit
_ [Explanation][Hint]The ABS ECU turns on the warning light in theIf the stop light operates normal, the ABS harness
following cases.
wire for the stop light switch input circuit to the ECUlStop light switch may remain on for more than
is broken or there is a malfunction in the ABS ECU.15 minutes without the ABS functions.
lThe harness wire for the stop light switch may
be open.
T AUTO-
TOPIGHT
WITCH
ABSECUDo the stop lights light up
Noand go out normally?c Check the stop light re-lated circuit and repair
Iproblem spots.
the ABS
ECUconnector and inspect at
>the harness side connec-
L No
When the brake pedal is
pressed
forcefullv, does thevoltage between’ connector
terminal No. 29 and ground
indicate battery voltage?Harness wire between
* stop light switch and ABS
ECU is broken.
J1 Repair harness.I
Yes
IStop light switch circuit isnormal.l

5-22BRAKES - Anti-lock Braking System Troubleshooting
1 E-4 1 Abnormality of solenoid valve drive circuit
[Explanation]
The ABS ECU normally monitors the solenoid valve
drive circuit.
If no current flows in the solenoid even if the ECU
when turned OFF, the ECU determines the solenoidcoil wire is broken/short circuited or the harness
isbroken short circuited and then warning light lights
turns the solenoid ON or if it continues to flow even
up.
J/B
HU
(
x:OMBINATION ME
:TER
MA0603
Is the resistance value for
the solenoid valve, that the
displayed trouble code indi-cates, within the range of
the standard values?
Standard value: 3.0-3.2 Q
Is the solenoid valve resist-
ance value, that the output
trouble code displays, withinthe range of the standard
values when measured at
the ECU connector?
Standard value: 3.0-3.2 B
nOrmll/
Solenoid valve drive circuit is
NoReplace HU.I
NoThe harness wire for thesolenoid valvecircuit
whose resistance value is
outside the range of the
standard value is broken
or short circuited.
I
1 Repair ABS harness.

BRAKES - Anti-lock Braking System Troubleshooting5-27
AABS warning light does not light at all.I-. [Explanation]
When it does not light up at all, there is a strong
possibility that there is trouble with ABS warning
light or with power to the light.
MAIN FUSIBLE
LINK
@
2
c-4
I 1~0~0~fWW-i
m2 ac
HU&,52&8--1
III
IA x A ,c
VALVE "I
RELAYI
1 IRELAY /--+I1 &-I I
\, J,. \ ,I L-1
I-----------A
I I
[Hint]If other warning lights do not light up either, fuse is
probably blown.
IGNITIONIGNITIONSWITCH (IG2)SWITCH (IGI)
10A10A p,
*2\I6-IM"
7,,14112131415161718I 9 I
iE4~oWERI.0(1111211311915116117
#$II;NATION
58
ABS ECU125
GNDGNDT7”

5-28BRAKES -Anti-lock Braking System Troubleshooting
With the ignition key in the “ON”
posi-NoCheck fuse No.ll. If it is
tion, do other warning lights illuminate?blown, correct the cause of
the blown fuse and then
replace the fuse.
YesTurn the ignition switch OFF and
Does voltage between
har-NOThe harness between the
nessNo. 14 and ground indicate
battery voltage?) fuse No.1 1 is broken.
YesCircuit in combination meter
is broken.
tRepair or replace com-
bination meter.II
IIIs the ABS warning light normal? (CheckNO) ABS warning light bulbReplace ABS warning
for burned bulb.)
burned.* light bulb.
I
Yes
- No
Are instrument panel wiring harness,
engine compartment wiring harness,
body wiring harness and ABS wiring
harness connectors connected properly?
c Connect connectors firmly.
(Check for pins pulled out or
bent, repair as needed.)
YesBroken wire in ECU, valve relay or both
drive circuits. Check and repair both
circuits.

5-34BRAKES -Anti-lock Braking System Troubleshooting
E-lInput abnormality of wheel speed sensorI.
[Explanation][Hint]s”rThe ABS ECU detects breaks in the wheel speed
In addition to a broken wire/short circuit in the wheel--sensor wire. The warning light lights up if the wheel
speed sensor, also check whether the sensor gap isspeed sensor signal RL is not input (or shorttoo large, rotor teeth are missing, sensor- harness
circuited) or if its output is low when starting to drivewire is temporarily broken, or sensor harness and
or while driving.body connector are not properly inserted.
E-2Output abnormality of wheel speed sensor
[Explanation]The warning light lights up when there is an
abnormality (other than broken wire or short circuit)
in the wheel speed sensor output signal while
driving.
[Hinti
The following can be considered as the cause of thewheel speed sensor output abnormality.
l Distortion of rotor, teeth missing
lLow frequency noise interference when sensor
harness wire is broken
l Noise interference
in sensor signall When the sensor output signal is below the
standard value or when amplitude modulation is
over the standard value, using an oscilloscope tomeasure the wave shape of the wheel speed
sensor output signal is very effective.
l Loose wheel bearing
l Temporarily broken wire in sensor harness
l Sensor harness and body connector are not
properly inserted.
NOTE
If contact is poor, check the sensor cable by bendingand lightly stretching it.
SPEED SENSOR
FRONTREARP%(LEFT SIDE)
(RIGHT SIDE)(LEFT SIDE)(RIGHT SIDE),’
1
FRONT SIDE
SELF-DIAGNOSISCHECK CONNECTOR14AO608

BRAKES - Anti-lock Braking System Troubleshooting5-37
E-4Abnormality of stop light switch circuitI
- [Explanation][Hint]The ABS ECU turns on the warning light in theIf the stop light operates normal, the ABS harness
following cases.
wire for the stop light switch input circuit to the ECU
lStop light switch may remain on for more thanis broken or there is a malfunction in the ABS ECU.
15 minutes without the ABS functions.
lThe harness wire for the stop light switch may
be open.
AUTO-CRUISE
STOP
--I0.85-G
’LIGHT
w
STOPLIGHTSWITCHABSECURESIS-
TOR
14AO610
Do the stop lights light up _ No c Check the stop light re-and go out normally?lated circuit and repair
problem spots.
Yes
isconnect the ABS ECconnector and inspect at
the harness side
connec-
tor.When the brake pedal is
NoHarness wire between
pressed forcefully, does the
* stop light switch and ABS
voltage between connectorECU is broken.
terminal No. 29 and ground
indicate battery voltage?
c
Repair harness.
Yes.
;gSJ;ght switch circuit is

5-38BRAKES - Anti-lock Braking System Troubleshooting
E-5Abnormality of solenoid valve drive circuit
[Explanation]*>The ABS ECU normally monitors the solenoid valve
when turned OFF, the ECU determines the solenoid%’ -’drive circuit.coil wire is broken/short circuited or the harness is
If no current flows in the solenoid even if the ECUbroken/short circuited and then the warning light
turns the solenoid ON or if it continues to flow evenlights up.
IGNITIONSWITCH(IGI)
7JIB------_-_tor and check with the
side connector.
Connect HU
1OP connec-
disconnect ECU con-
>Is the solenoid valve resis-
tance value within the range
of the standard values when
measured at the ECU con-
nector?Standard value:
3.0-3.2 Q
Yes1
II
I
Solenoid valve drive circuit isnormal.I
NoReplace HU.I
NoIs the resistance value for
the solenoid valve within the
range ofthe standard
values?Standard value:
3.0-3.2 Q, IYes ,
1
JThe harness wire for the
solenoidvalvecircuit
whose resistance value is
outside the range of the
standard value is broken
or short circuited.,-‘he-
-Repair