1999 MITSUBISHI LANCER EVOLUTION VI ABS

GENERAL – How to Use Troubleshooting/Inspection Service Points00-8
WHEN USING THE WARNING LAMP
1. Use the special tool to earth No.1 terminal (diagnosis
control terminal) of the diagnosis connector.
2. To check ABS system, remove the valve relay.
NOTE
That is because the valve relay is off and the warning
lamp remains illuminated if there is a fault in the ABS
system.
3. Turn on the ignition switch.
4. Read out a diagnosis code by observing how the warning
lamp flashes.
Applicable systems
System nameWarning lamp name
MPIEngine warning lamp
AY CAYC warning lamp
ABSABS warning lamp
Indication of diagnosis code by warning lamp
When the diagnosis code No.24 is outputWhen no diagnosis code is output*
On
Off
1.5 secs.0.5 sec.0.5 sec.
Pause
time 3
secs.Tens
signalPlace
division
2 secs.Units
signal
On
Off
0.5 sec.
NOTE
*: Even if the ABS system is normal, removing the valve relay causes the diagnosis code No.52 to
be output.
WHEN USING THE VOLTMETER
Use the special tool to connect the diagnosis output terminals
and the earth terminal of the diagnosis connector to a voltmeter
and take a reading of the diagnosis codes from the movement
of the needle.
Voltmeter connection terminals
System namePositive connection
terminalNegative connec-
tion terminal
Full-auto air
conditioner114 or 5
Diagnosis connector
MB991529
Earth terminal
Full-auto air con-
ditioner terminal
MB991529

ENGINE – Specifications11-10
FORM-IN-PLACE GASKET
The engine has several areas where the form-in-place gasket (FIPG) is in use. To ensure that the gasket
fully serves its purpose, it is necessary to observe some precautions when applying the gasket. Bead
size, continuity and location are of paramount importance. Too thin a bead could cause leaks. Too thick
a bead, on the other hand, could be squeezed out of location, causing blocking or narrowing of the
fluid feed line. To eliminate the possibility of leaks from a joint, therefore, it is absolutely necessary to
apply the gasket evenly without a break, while observing the correct bead size.
The FIPG used in the engine is a room temperature vulcanisation (RTV) type and is supplied in a 100-gram
tube (Part No. MD970389). Since the RTV hardens as it reacts with the moisture in the atmospheric
air, it is normally used in the metallic flange areas. The FIPG, Part No. MD970389, can be used for
sealing both engine oil and coolant, while Part No. MD997110 can only be used for engine oil sealing.
Disassembly
The parts assembled with the FIPG can be easily disassembled without use of a special method. In
some cases, however, the sealant between the joined surfaces may have to be broken by lightly striking
with a mallet or similar tool. A flat and thin gasket scraper may be lightly hammered in between the
joined surfaces. In this case, however, care must be taken to prevent damage to the joined surfaces.
For removal of the oil pan, the special tool “Oil Pan Remover” (MD998727) is available. Be sure to use
the special tool to remove the oil pan.
Surface Preparation
Thoroughly remove all substances deposited on the gasket application surfaces, using a gasket scraper
or wire brush. Check to ensure that the surfaces to which the FIPG is to be applied is flat. Make sure
that there are no oils, greases and foreign substances deposited on the application surfaces. Do not
forget to remove the old sealant remained in the bolt holes.
Form-in-Place Gasket Application
When assembling parts with the FIPG, you must observe some precautions, but the procedures is very
simple as in the case of a conventional precut gasket.
Applied FIPG bead should be of the specified size and without breaks. Also be sure to encircle the
bolt hole circumference with a completely continuous bead. The FIPG can be wiped away unless it is
hardened. While the FIPG is still moist (in less than 15 minutes), mount the parts in position. When
the parts are mounted, make sure that the gasket is applied to the required area only. In addition, do
not apply any oil or water to the sealing locations or start the engine until a sufficient amount of time
(about one hour) has passed after installation is completed.
The FIPG application procedure may vary on different areas. Observe the procedure described in the
text when applying the FIPG.

MPI – Troubleshooting13-39
INSPECTION PROCEDURE 28
Power steering fluid pressure switch system
Probable cause
The presence or absence of power steering load is input to the engine-ECU.
The engine-ECU controls the idle speed control (ISC) servo based on this input.
Malfunction of power steering fluid pressure switch

Improper connector contact, open or short-circuited
harness wire

Malfunction of the engine-ECU
Check the power steering fluid pressure switch.NG
Replace
OK
Measure at the power steering fluid pressure switch connector
A-101.

Disconnect the connector, and measure at the harness side.

Voltage between 1 and earth (Ignition switch: ON)
OK:System voltageNGCheck the following
connectors: A-28, B-60NG
Repair
OK
Check trouble symptom.
NG
Check harness wire be-
tween engine-ECU and
power steering fluid pres-
sure switch connector.NG
Repair
OK
Replace the engine-ECU.
OK
Check the following
connector: A-101NG
Repair
OK
Check trouble symptom.
NG
Replace the engine-ECU.
INSPECTION PROCEDURE 29
A/C switch and A/C relay system
Probable cause
When an A/C ON signal is input to the engine-ECU, the engine-ECU carries out
control of the idle speed control (ISC) servo, and also operates the A/C compressor
magnetic clutch.
Malfunction of A/C control system

Malfunction of A/C switch

Improper connector contact, open or short-circuited
harness wire

Malfunction of the engine-ECU
Check the A/C compressor relay.
(Refer to GROUP 55 – On-vehicle Service.)NG
Replace
OK
Measure at the engine-ECU connectors B-59, B-60.

Disconnect the connector, and measure at the harness side.

Voltage between 22 and earth, and 45 and earth
(Ignition switch: ON, A/C switch: ON)
OK:System voltage

Short-circuit between 22 and earth
(Ignition switch: ON, A/C switch: ON)
OK:A/C compressor clutch turns on.NGCheck the A/C system. (Refer to GROUP 55 – On-vehicle Service.)
OKCheck the following
connectors: B-59, B-60NG
Replace
OK
Check trouble symptom.
NG
Replace the engine-ECU.

27-1
REAR AXLE
CONTENTS
GENERAL 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Outline of Change 2. . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE SPECIFICATIONS 2. . . . . . . . . . . . . .
LUBRICANT 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOLS 3. . . . . . . . . . . . . . . . . . . . . . . .
TROUBLESHOOTING 4. . . . . . . . . . . . .
ON-VEHICLE SERVICE
31. . . . . . . . . . . . . . .
Rear Axle Total Backlash Check 31. . . . . . . . . . .
Gear Oil Level Check 31. . . . . . . . . . . . . . . . . . . .
Gear Oil Change 32. . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Level Check 33. . . . . . . . . . . . . . . . . . . . . . . . Bleeding 34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AYC Operation Check 34. . . . . . . . . . . . . . . . . . . .
Hydraulic Pressure Check 35. . . . . . . . . . . . . . . . .
Differential Carrier Oil Seal
Replacement 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wheel Speed Sensor Output Voltage
Measurement 37. . . . .
Action When Battery Runs Out 38. . . . . . . . . . . .
HYDRAULIC UNIT
39. . . . . . . . . . . . . . .
SENSOR RELAY
41. . . . . . . . . . . . . . .
AYC-ECU 42. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

REAR AXLE – Troubleshooting 27-5
3. INSPECTION CHART FOR DIAGNOSIS CODE
Diagnosis
code No.Diagnosis itemsRef. page
12Power supply voltage (valve power supply) system (open- or short-circuit)27-6
21FR wheel speed sensor system (open- or short-circuit)27-6
22FL wheel speed sensor system (open- or short-circuit)27-6
23RR wheel speed sensor system (open- or short-circuit)27-6
24RL wheel speed sensor system (open- or short-circuit)27-6
25Wrong-diameter tire27-8
26Faulty wheel speed sensor27-9
31Steer sensor (ST-1, ST-2, ST-N) system (open-circuit)27-10
32Steer sensor (ST-N) system (short-circuit)27-10
33Steer sensor (ST-N) system27-11
34Steer sensor (ST-1, ST-2) system (short-circuit)27-11
41TPS system (open- or short-circuit)27-12
51Longitudinal acceleration sensor system (open- or short-circuit)27-12
52Longitudinal acceleration sensor27-13
56Lateral acceleration sensor system (open- or short-circuit)27-12
61Stop lamp switch system (open-circuit)27-13
65ABS monitor system (open-circuit or defective ABS)27-14
71Proportioning valve system (open- or short-circuit)27-14
72Directional control valve (right) system (open- or short-circuit)27-15
73Directional control valve (left) system (open- or short-circuit)27-16
81AYC relay system (open- or short-circuit)27-17
82Electric pump system27-18
83Electric pump system27-19

REAR AXLE – Troubleshooting 27-6
4. INSPECTION PROCEDURES FOR DIAGNOSIS CODES
Code No. 12: Power supply voltage (valve power supply)
systemProbable cause
This code is output when the AYC-ECU power supply voltage drops below, goes
beyond, a specified level.
Defective harness or connector

Defective battery

Defective AYC-ECU
NOTE
Refer to the corresponding item if any other diagnosis code is being output.
Is the battery voltage correct?NG
Replace
OK
Measure at B-96 AYC-ECU connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON

Voltage across 31 and body ground
OK:System voltageNGCheck the following connectors:
B-96, B-94, B-49, B-75, B-76
OK
Check the trouble symptom.
NG
Check and repair harness between
ignition switch (IG
2) and AYC-ECU. OKReplace AYC-ECU.NG
Repair
Code Nos. 21, 22, 23, 24: Wheel speed sensor systemProbable cause
This code is output if any one of three wheel speed sensors fails to provide an input
even after the other wheel exceeded 8 km/h.
Defective harness or connector

Defective ABS-ECU

Defective AYC-ECU

NG
Replace AYC-ECU.
OK
Replace ABS-ECU.
NG
Check harness between AYC-ECU
and ABS-ECU.NG
Repair
OK
Check the trouble symptom.
Is an ABS diagnosis code No. 21, 22,
23, or 24 output?YESRefer to Group 35B – Troubleshooting
NO
Measure at B-95 AYC-ECU connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON

Turn tire at 1/2 to 1 revolution/sec.

Voltage across 6/7/8/9 and body
ground
OK:42 mV or more (when mea-
sured with a circuit tester)
120 mV-P or more (when
measured with an oscillo-
scope)OKCheck the following connector:
B-95
OK
Check the trouble symptom.
NG
Check the following connectors:
B-24, B-95NG
RepairNG
Repair

REAR AXLE – Troubleshooting 27-7

OK
Check the wheel bearing.
NG
Check and repair the harness between
wheel speed sensor and AYC-ECU.
NG
Replace AYC-ECU.
OK
Check the trouble symptom.
OK
Check the following connector:
B-95NG
Repair
OK
Check the trouble symptom.
OK
Check the following connectors:
B-95, B-52, B-17, A-26, A-50, D-04,
D-14, D-19NG
Repair
OK
Measure at B-95 AYC-ECU connector.

Disconnect the connector and
measure at the harness side.

Resistance across 7-20 (front, LH),
6-19 (front, RH), 9-22 (rear, LH),
and 8-21 (rear, RH).
OK:1.4 – 1.8 kΩ.NGCheck the wheel speed sensor. (Refer
to Group 35B.)
Check the installation of wheel speed
sensor.NG
Repair
OK
Check the wheel speed sensor output
voltage. (Refer to P.27-37)NGCheck the wheel speed sensor and
ABS rotor. (Refer to Group 35B.)NG
Replace
NG
Replace

REAR AXLE – Troubleshooting 27-8
Code No. 25: Wrong-diameter tireProbable cause
This code is output if the speed of any one of the four wheels exceeds a specified
level with respect to the average of the four wheel speed sensor outputs when the
steering wheel is in the straight-ahead position and the vehicle speed exceeds 20
km/h. At this time, the warning lamp does not light up.
Defective harness or connector

Defective AYC-ECU

Defective ABS-ECU

OK
Replace ABS-ECU.
NG
Check harness between AYC-ECU
and ABS-ECU.NG
Repair
NG
Replace AYC-ECU.
OK
Check the trouble symptom.
NG
Check the following connectors:
B-24, B-95NG
Repair
OK
Check the trouble symptom.
NO
Measure at B-95 AYC-ECU connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON

Turn tire at 1/2 to 1 revolution/sec.

Voltage across 6/7/8/9 and body
ground.
OK:42 mV or more (when mea-
sured with a circuit tester)
120 mV-P or more (when
measured with an oscillo-
scope)OKCheck the following connector:
B-95
YES
Is ABS diagnosis code No. 15 output?YESGroup 35* – Refer to Troubleshooting
Are correct tires mounted on all four
wheels?NO
Repair
NG
Repair

NO
Repair
NOCheck and repair the harness between
wheel speed sensor and AYC-ECU.
OK
Check the trouble symptom.
OK
Check the following connectors:
B-95, B-52, B-17, A-26, A-50, D-04,
D-14, D-19NG
Repair
OK
Check wheel bearing.NG
Replace
NG
Replace AYC-ECU.
OK
Check the trouble symptom.
OK
Check the following connector:
B-95NG
Repair
OK
Check wheel speed sensor output volt-
age. (Refer to p. 27-37.)NGCheck wheel speed sensor and ABS
rotor. (Refer to Group 35B.)
YES
Check Wheel speed sensor for instal-
lation.NG
Repair
Are correct tires mounted on all four
wheels?
NG
Replace