ABS MITSUBISHI LANCER EVOLUTION IV 1998 Workshop Manual

MPI – Troubleshooting13-6
TROUBLESHOOTING
1. DIAGNOSIS FUNCTION
1-1 ENGINE WARNING LAMP (CHECK ENGINE LAMP)
If an abnormality occurs in any of the following items related
to the Multipoint Fuel Injection (MPI) system, the engine
warning lamp will illuminate.
If the lamp remains illuminated or if the lamp illuminates while
the engine is running, check the diagnosis code output.
Engine warning lamp inspection items
Engine-ECU
Air flow sensor (AFS)
Intake air temperature sensor
Throttle position sensor (TPS)
Engine coolant temperature sensor
Crank angle sensor
Camshaft position sensor
Barometric pressure sensor
Detonation sensor
Injector
Ignition coil, power transister
Misfire
1-2 METHOD OF READING AND ERASING DIAGNOSIS
CODES
(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 off the ignition switch.
(4) Read out a diagnosis code by observing how the warning
lamp flashes.
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
A03X0113
On
Off
0.5 sec.
0.25 sec.
NOTE
*: Even if the ABS system is normal, removing the valve relay causes the diagnosis code No.52 to
be output.
Engine warning lamp
(check engine lamp)

MPI – Troubleshooting13-27

Observation conditions
Probe selector switch× 10
AC-GND-DCDC
VOLTS/DIV.1 V
TIME/DIV.0.5 ms
Misc.–
Engine speedIdle

The power supply voltage is being normally applied and, when a signal is received from the engine
ECU, the voltage drops to around 0 V for the period of time equivalent to its drive signal.
When the signal from the engine ECU turns OFF, the counter emf of the coil causes a voltage peak
to develop, thus resuming the power supply voltage.
Injector drive time:
The fuel injection time as determined by the engine ECU according to the output values of sensors
including AFS. Injector drive time = effective injection time + invalid injection time (Invalid injection
time: corrects operation time lag caused by a power supply voltage drop)
Solenoid coil counter emf:
When the signal from the engine ECU turns OFF, counter emf occurs in the injector coil (approx.
65 to 75 V).
Power supply voltage:
The power supply voltage is being applied in the absence of a signal from the engine ECU. If this
voltage is low, it extends the invalid injection time and, thus, the drive time.

Point A: Strength of solenoid coil counter emf
Solenoid coil counter emf is low or zero.Injector solenoid shorting
Point B: Injector drive time
When the engine is suddenly raced, the drive time temporarily
extends by a wide margin and soon returns to the normal
drive time corresponding to the engine speed.
Point A
Point B
Injector
drive timeSolenoid counter emf
(approx. 7 × 10 V)
Power supply voltage
At idle
During racing

ENGINE COOLING – Thermostat14-4
INSTALLATION SERVICE POINTS
ATHERMOSTAT INSTALLATION
(1) Install the thermostat so that the jiggle valve is facing
straight up.
Caution
Make absolutely sure that no oil is adhering to the
rubber ring of the thermostat. If the rubber ring is
damaged, replace the thermostat.
(2) When assembling the thermostat, be careful not to fold
over or scratch the rubber ring.
BRADIATOR LOWER HOSE CONNECTION
(1) Insert each hose as far as the projection of the water
inlet fitting.
(2) Align the mating marks on the radiator hose and hose
clamp, and then connect the radiator hose.
INSPECTION
THERMOSTAT CHECK
(1) Immerse the thermostat in water, and heat the water while
stirring. Check the thermostat valve opening temperature.
Standard value: 76.5 ± 1.5
C
(2) Check that the amount of valve lift is at the standard
value when the water is at the full-opening temperature.
Standard value:
Full-opening temperature: 90
C
Amount of valve lift: 8.5 mm or more
NOTE
Measure the valve height when the thermostat is fully
closed, calculate the valve lift by subtracting this
measurement from the valve height when the thermostat
is fully open.
Jiggle valve
Rubber ring
Valve lift

MANUAL TRANSMISSION – Transmission Assembly22A-8
16 18
Unit: Nm {kgfm}
52 {5.3}*
19
17
9
10
12
1315
1214
69 {7.0} 69 {7.0} 15 – 33
{1.5 – 3.4} 39 {4.0}59 – 71
{6.0 – 7.2} 26 – 33
{2.7 – 3.4}48 {4.9}
52 {5.3}*
Lifting up of the vehicle
9. Stabilizer bar connection
10. Wheel speed sensor cable connec-
tion
11. Brake hose clamp
12. Tie rod end connection
13. Lower arm ball joint connection
A
Clutch release bearing connection
14. Centermember assembly
B15. Drive shaft connection
B16. Drive shaft connection

Strut assembly
(Refer to GROUP 33A.)C17. Output shaft

Air hose A
(Refer to GROUP 15 – Intercooler.)
18. Transmission assembly lower part
coupling bolts
19. Transmission assembly
Caution
Mounting locations marked by * should be
provisionally tightened, and then fully tightened
when the body is supporting the full weight of the
engine.

MANUAL TRANSMISSION OVERHAUL – Sealants and Adhesives22B-5
SEALANTS AND ADHESIVES
TRANSMISSION
ItemsSpecified sealants and adhesives
Clutch housing-transmission case mating surfaceTHREEBOND 1216
Control housing-transmission case mating surface
Under cover-transmission case mating surface
Air breatherTHREEBOND 1501
Center differential drive gear boltTHREEBOND 1303 or LOKTITE 648
TRANSFER
ItemsSpecified sealants and adhesives
Air breatherTHREEBOND 1501
FORM-IN-PLACE GASKET
The transmission 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.
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.
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 remaining in the bolt holes.
FORM-IN-PLACE GASKET APPLICATION
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 10 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.

27-1
REAR AXLE
CONTENTS
SERVICE SPECIFICATIONS 2. . . . . . . . . . . . . .
LUBRICANT 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SEALANT 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOLS 3. . . . . . . . . . . . . . . . . . . . . . . .
TROUBLESHOOTING 5. . . . . . . . . . . . .
ON-VEHICLE SERVICE
27. . . . . . . . . . . . . . .
1. Rear Axle Total Backlash Check 27. . . . . . .
2. Gear Oil Level Check 27. . . . . . . . . . . . . . . .
3. Gear Oil Change 28. . . . . . . . . . . . . . . . . . . . .
4. Fluid Level Check 29. . . . . . . . . . . . . . . . . . . .
5. Bleeding 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6. Differential Carrier Oil Seal
Replacement 30. . . . . . . . . . . . . . . . . . . . . . . . .
7. Speed Sensor Output Voltage
Measurement 31.
8. Action When Battery Runs Out 32. . . . . . . .
REAR HUB ASSEMBLY 33. . . . . . . . . . . . . . . .
KNUCKLE 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DRIVE SHAFT 36. . . . . . . . . . . . . . . . . . . . . . . . .
DIFFERENTIAL CARRIER
39.
DIFFERENTIAL CARRIER
41. . . . . . . . . . . . . . . . . . .
TORQUE TRANSFER DIFFERENTIAL
43. . . . . . . . . . . . . . .
LSD CASE ASSEMBLY
46. . . . . . . . . . .
HYDRAULIC UNIT
50. . . . . . . . . . . . . . .
SENSOR RELAY
52. . . . . . . . . . . . . . .
AYC-ECU 53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

REAR AXLE – Troubleshooting 27-6
3. INSPECTION CHART FOR DIAGNOSIS CODE
Diagnosis
code No.Diagnosis itemsRef. page
12Power supply voltage (valve power supply) system (open- or short-circuit)27-7
21FR wheel speed sensor system (open- or short-circuit)27-7
22FL wheel speed sensor system (open- or short-circuit)27-7
23RR wheel speed sensor system (open- or short-circuit)27-7
24RL wheel speed sensor system (open- or short-circuit)27-7
25Wrong-diameter tire27-9
26Faulty wheel speed sensor27-10
31Steer sensor (ST-1, ST-2, ST-N) system (open-circuit)27-11
32Steer sensor (ST-N) system (short-circuit)27-11
33Steer sensor (ST-N) system27-12
34Steer sensor (ST-1, ST-2) system (short-circuit)27-12
41TPS system (open- or short-circuit)27-13
51Longitudinal acceleration sensor system (open- or short-circuit)27-13
52Longitudinal acceleration sensor27-14
56Lateral acceleration sensor system (open- or short-circuit)27-13
61Stop lamp switch system (open-circuit)27-14
65ABS monitor system (open-circuit or defective ABS)27-15
71Proportioning valve system (open- or short-circuit)27-15
72Directional control valve (right) system (open- or short-circuit)27-16
73Directional control valve (left) system (open- or short-circuit)27-17
81AYC relay system (open- or short-circuit)27-18
82Electric pump system27-19
83Electric pump system27-20

REAR AXLE – Troubleshooting 27-7
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:Battery 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 No. 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

OK
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?YESTroubleshooting
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 27-8

OK
Check the wheel bearing.
NG
Check and repair the harness between
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 speed sensor.
Check the installation of speed sensor.NG
Repair
OK
Check the speed sensor output volt-
age. (Refer to P.27-31.)NGCheck the speed sensor and rotor.NG
Replace
NG
Replace

REAR AXLE – Troubleshooting 27-9
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: OK

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?YESTroubleshooting
Are correct tires mounted on all four
wheels?NO
Repair
NG
Repair

NG
Check and repair the harness between
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 speed sensor output voltage.
(Refer to p. 27-31.)NGCheck speed sensor and rotor.
YES
Check speed sensor for installation.NG
Repair
Are correct tires mounted on all four
wheels?NO
Repair
NG
Replace