relay MITSUBISHI LANCER EVOLUTION IV 1998 Owner's Manual

REAR AXLE – Troubleshooting <AYC>27-26
7-2 LISTING OF RESISTANCE AND CONTINUITY ACROSS CONNECTOR TERMINALS ON
HARNESS SIDE
(1) Measure the resistance and check for continuity with the ignition switch in the “OFF” position and
AYC-ECU connector disconnected.
(2) Measure the resistance and check for continuity across terminals listed below.
(3) Fig. below shows the arrangement of terminals.
Terminal No.Signal nameNormally
2 – body groundLongitudinal acceleration sensor ground, lateral acceleration sensor groundConducting
26 – body groundECU groundConducting
35 – body groundAYC motor relayConducting
37 – body groundDirectional control valve (right)15.4 – 16.4 Ω
38 – body groundProportioning valve3.4 – 4.0 Ω
45 – body groundDirectional control valve (left)15.4 – 16.4 Ω
46 – body groundECU groundConducting
6 – 19*2Speed sensor (front, RH)1.4 – 1.8 Ω
7 – 20*2Speed sensor (front, LH)1.4 – 1.8 Ω
8 – 21*2Speed sensor (rear, RH)1.4 – 1.8 Ω
9 – 22*2Speed sensor (rear, LH)1.4 – 1.8 Ω
NOTE
*2: Indicates the vehicles without ABS.

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

REAR AXLE – Sensor Relay <Vehicles with AYC>27-52
SENSOR RELAY <VEHICLES WITH AYC>
REMOVAL AND INSTALLATION
12
3
4
Steer sensor removal steps
Steering wheel and column cover
(Refer to GROUP 37 – Steering Wheel
and Shaft.)
A1. Steer sensorAcceleration sensor and AYC relay
removal
2. Longitudinal acceleration sensor
3. Lateral acceleration sensor
4. AYC relay
NOTE
For the wheel speed sensor, refer to GROUP 35B.
REMOVAL SERVICE POINT
ASTEER SENSOR REMOVAL
Remove the steer sensor from the column switch.
Caution
(1) A photocoupler is used as the steer sensor. Use care
not to allow dust or grease to be on the sensor.
(2) Do not bend or dirty with grease the slit plate on
the column switch side.Slit plate
Steer sensor

REAR AXLE – Sensor Relay <Vehicles with AYC> / AYC-ECU27-53
INSPECTION
1. LONGITUDINAL AND LATERAL ACCELERATION
SENSOR CHECK
Refer to GROUP 35B – Acceleration Sensor.
2. AYC RELAY CONTINUITY CHECK
Battery voltageTerminal No.
1345
When not energized
When energized
AYC-ECU
REMOVAL AND INSTALLATION
Pre-removal and Post-installation Operation
Front Floor Console Removal and Installation
Unit: Nm {kgf
m}
5 {0.5}
AYC-ECU
5 {0.5}

ABS – Troubleshooting35B-2
The EVOLUTION-V is provided with a lateral acceleration sensor in addition to the longitudinal acceleration
sensor, and the ABS-ECU connector is changed in terminal arrangement. When servicing EVOLUTION-V,
therefore, use the following service procedures.
TROUBLESHOOTING
1. INSPECTION CHART FOR DIAGNOSIS CODES
Diagnosis
code No.Diagnosis itemsReference Page
11Wheel speed sensor (FR) system (open- or short-circuit)35B-3
12Wheel speed sensor (FL) system (open- or short-circuit)35B-3
13Wheel speed sensor (RR) system (open- or short-circuit)35B-3
14Wheel speed sensor (RL) system (open- or short-circuit)35B-3
15Wheel speed sensor system (abnormal output signal)35B-4
16ABS-ECU power supply voltage system (abnormal voltage drop or rise)35B-5
21Wheel speed sensor (FR) system35B-2
22Wheel speed sensor (FL) system35B-2
23Wheel speed sensor (RR) system35B-2
24Wheel speed sensor (RL) system35B-2
27AYC monitor system (detective AYC)35B-6
32Longitudinal acceleration sensor circuit system35B-6
33Stop lamp switch system35B-7
41Solenoid valve (FR) system35B-7
42Solenoid valve (FL) system35B-7
43Solenoid valve (RR) system35B-7
44Solenoid valve (RL) system35B-7
51Valve relay system35B-8
53Motor relay system35B-9
63ABS-ECU failureReplace ABS-ECU.
71Lateral acceleration sensor system35B-10

ABS – Troubleshooting35B-5
Code No.16: ABS-ECU power supply system (abnormal
voltage drop or rise)Probable cause
This code is output if the ABS-ECU or valve relay power supply voltage drops below
or rises above the rated values.
The valve relay power supply voltage is detected based on the voltage in the valve
relay monitor line.
Malfunction of battery

Malfunction of wiring harness or connector

Malfunction of valve relay

Malfunction of ABS-ECU
Caution
If battery voltage drops or rises during inspection, this code will be output as well, making it
impossible to obtain correct diagnostic results.
Before carrying out the following inspection, check the battery level, and refill it if necessary.
OK
Replace ABS-ECU.
OK
Replace the ABS-ECU.
OK
Check the trouble symptom.NGCheck the harness wire, and repair
if necessary.

Between ignition switch and
ABS-ECU
OK
Check the trouble symptom.NGCheck the harness wire, and repair
if necessary.

Between general-purpose fuse
No. 6 and valve relay
NG
Repair
OK
Check the harness wire for short
circuit, and repair if necessary.

Between valve relay and hydraulic
unit

Between valve relay and motor
relayNG
Repair OK
NG
Check the harness wire, and repair
if necessary.

Between valve relay and ABS-ECUNG
Repair
OK
Check the trouble symptom.
OK
Check the trouble symptom.NGCheck the harness wire, and repair
if necessary.

Between general-purpose fuse
No. 6 and valve relay
OK
Measure at the ABS-ECU connector
B-25.

Connector connected

Ignition switch: ON
(1) Voltage between 37 and body
ground
OK:Battery voltage
(2) Voltage between 48 and body
ground
OK:Battery voltage(1) NGCheck the following connectors:
A-76, B-25NG
Repair
(2) NG
Check the following connectors:
A-76, B-25NG
Repair
OK
Check the valve relay.NG
Replace
OK
Check the trouble symptom.NGCheck the harness wire, and repair
if necessary.

Between fusible link No. 8 and
valve relay
OK
Measure at the valve relay connector
A-76.

Disconnect the connector, and
measure at the harness side
connector.

Ignition switch: ON
(1) Voltage between 6 and body
ground
OK:Battery voltage
(2) Voltage between 2 and body
ground
OK:Battery voltage(1) NGCheck the following connector:
A-76NG
Repair
(2) NGCheck the following connector:
A-76NG
Repair
Measure at the ABS-ECU connector
B-24.

Disconnect the connector, and
measure at the harness side
connector.

Start the engine.

Voltage between 13 and body
ground
OK:Battery voltageNGCheck the following connectors:
B-24, B-52, B-74, B-76NG
Repair

ABS – TroubleshootingABS – Troubleshooting35B-6
Code No. 27: AYC monitor system (defective AYC)Probable cause
This code is output when the AYC monitor signal becomes faulty.
Defective AYC-ECU

Defective ABS-ECU

Defective harness or connector
OK
Replace the ABS-ECU.
OK
MUT-II data list
AYC signal
OKOFF to be displayed when the
engine runs at idle with the
vehicle stationary.NGReplace AYC-ECU.
OK
Check the harness between ABS-ECU
and AYC-ECU.NG
Repair
Check the following connectors:
B-25, B-96NG
Repair
Code No. 32: Acceleration sensor (longitudinal accelera-
tion) circuit systemProbable cause
This code is output under either of the following conditions:

The output from the acceleration sensor (longitudinal acceleration) becomes 0.5
V or less, or 4.5 V or more.

The acceleration sensor (longitudinal acceleration) harness is open- or
short-circuited.
Defective acceleration sensor (longitudinal accelera-
tion)

Defective harness or connector

Defective ABS-ECU
OK
Check the trouble symptom.NGReplace ABS-ECU.
OK
Check the trouble symptom.NGCheck and repair the harness between
acceleration sensor (longitudinal
acceleration) and ABS-ECU.
OK
Check the trouble symptom.NGCheck and repair the harness between
general-purpose fuse No. 6 and
acceleration sensor (longitudinal
acceleration).
OK
Replace ABS-ECU.
OK
Check the following connector:
B-24NG
Repair
OK
Measure at B-24 ABS-ECU connector.

Connect the connector.

Ignition switch: ON

Voltage across 4 and 17
OK:2.4 – 2.6 V
(horizontal position)NGCheck the following connectors:
B-24, D-20, B-52NG
Repair
NG
Check the harness between accelera-
tion sensor (longitudinal acceleration)
and ABS-ECU.NG
Repair
OK
Check the trouble symptom.
OK
Check the valve relay.NG
Replace
(1) NGCheck the following connectors:
D-20, B-49, B-75NG
Repair
Check the following connector:
D-20, B-49, B-75NG
Repair
(2) NG
Measure at D-20 acceleration sensor
(longitudinal acceleration) connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON
(1) Voltage across 1 and body ground
OK:Battery voltage
(2) Continuity across 3 and body
ground
OK:Conducting

ABS – Troubleshooting35B-7
Code No.33: Stop lamp switch system (open circuit or
stop lamp stays ON)Probable cause
This code is output, if the stop lamp switch is continuously on for 15 minutes or
more.
Malfunction of stop lamp switch

Malfunction of wiring harness or connector

Malfunction of ABS-ECU
OK
Check the trouble symptom.NGCheck the harness wire, and repair
if necessary.

Between dedicated fuse No. 11
and ABS-ECU
OK
Check the trouble symptom.NGReplace the ABS-ECU.
OK
Check the trouble symptom.NGCheck the harness wire, and repair
if necessary.

Between stop lamp switch and
ABS-ECU
OK
Check the following connectors:
B-15, B-21, B-25, B-32, B-65NG
Repair
OK
Check the following connector:
B-25NG
Repair
YES
Measure at the ABS-ECU connector
B-25.

Disconnect the connector, and
measure at the harness side
connector.

Stop lamp switch: ON

Voltage between 34 and body
ground
OK:Battery voltageNG
Check the following connectors:
B-25, B-32, B-65NG
Repair
OK
Stop lamp switch checkNG
Repair
Does the stop lamp turn on and off
normally?NOStop lamp switch installation checkNG
Repair
Code No. 41, 42, 43, 44: Solenoid valve systemProbable cause
ABS-ECU monitors the solenoid valve energization circuit at all times. This code is
output when no current flows through the solenoid even when ABS-ECU energizes
it or when current continues flowing through the solenoid even when ABS-ECU
deenergizes it, which is considered to be attributable to an open- or short-circuited
solenoid coil or open- or short-circuited harness.
Defective hydraulic unit

Defective harness or connector

Defective ABS-ECU
OK
Replace the ABS-ECU.
OK
Check the trouble symptom.NGCheck the harness between hydraulic
unit (solenoid valve) and ABS-ECU.NG
Repair
OK
Check the trouble symptom.NGCheck and repair the harness between
hydraulic unit and valve relay.
OK
Check the following connectors:
A-21, B-24, B-25NG
Repair
OK
Measure at A-22 hydraulic unit connec-
tor and A-76 valve relay connector.

Disconnect the connector and
measure at the harness side.

Continuity across the following
terminals
Hydraulic Valve relay
unit side side
11–3
OK:Battery voltageNGCheck the following connectors:
A-22, A-76NG
Repair
Check the solenoid valve.NGReplace the hydraulic unit.

ABS – Troubleshooting35B-8
Code No. 51: Valve relay systemProbable cause
This code is output under any of the following conditions:

The solenoid valve power is not supplied when ABS-ECU attempts to turn ON
the valve relay as part of the initial check when the ignition switch is turned ON.

The solenoid valve power remains supplied when ABS-ECU attempts to turn OFF
the valve relay as part of the initial check when the ignition switch is turned ON.

The solenoid valve power is not supplied while the valve relay remains ON under
normal conditions.
Defective ABS valve relay

Defective harness or connector

Defective ABS-ECU
NOTE
In the diagnosis code reading by means of the ABS warning lamp, this code is output in addition to
the actual diagnosis code since the valve relay connector is disconnected.
If the ABS warning lamp turns ON even when the spot represented by the diagnosis code output in
addition to this code has been repaired, and if no diagnosis code other than No. 51 is output, then
the valve relay system is probably defective. Make the following checks.
OK
Check the trouble symptom.NGCheck and repair the harness between
general-purpose fuse No. 6 and valve
relay.
NG
Replace the ABS-ECU.
OK
Check the trouble symptom.
OK
Check the trouble symptom.NGCheck and repair the harness between
valve relay and ABS-ECU.
OK
Check the following connectors:
A-76, B-25NG
Repair
OK
Measure at A-76 valve relay connector
and B-25 ABS-ECU connector.

Disconnect the connector and
measure at the harness side.

Continuity across the following
terminals
OK:Conducting
Valve relay ABS-ECU
side side
3–48
5–37NGCheck the following connectors:
A-76, B-25NG
Repair
OK
Check the trouble symptom.NGCheck and repair the harness between
fusible link No. 8 and valve relay.
OK
Measure at A-76 valve relay connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON
(1) Voltage across 6 and body ground
(2) Voltage across 2 and body ground
OK:Battery voltage(1) NGCheck the following connector:
A-76NG
Repair
(2) NG
Check the following connector:
A-76NG
Repair
Check the valve relay.NG
Replace

ABS – Troubleshooting35B-9
Code No. 53: Motor relay systemProbable cause
This code is output under any of the following conditions:

No signals are input to the motor monitor when the motor relay is ON (motor
does not run, etc.).

A signal is being input to the motor monitor for 3 sec. or more when the motor
relay is OFF (motor continues running, etc.).

The motor relay is inoperative.
Defective motor relay

Defective harness or connector

Defective hydraulic unit

Defective ABS-ECU
Caution
(1) If the motor relay contacts fuse, the motor continues running even when the ignition switch
is turned OFF. In this case, immediately remove fusible link No. 8 (60 A) or disconnect the
A-22 connector or A-77 motor relay connector of the hydraulic unit. Overloading the motor
results in a rundown battery.
(2) Driving the motor through actuator test runs down the battery. After the test, run the engine
for some while.
OK
Check the trouble symptom.NGCheck and repair the harness between
fusible link No. 8 and motor relay.
OK
Check the trouble symptom.NGCheck and repair the harness between
motor relay and hydraulic unit.
OK
Check the trouble symptom.NGCheck and repair the harness between
motor relay and ABS-ECU motor
monitor terminal No. 49.
OK
Check the motor for operation.NGReplace ABS-ECU.
OK
Check the following connectors:
A-22, A-77, B-25NG
Repair
OK
Check the motor for operation.NGReplace the hydraulic unit.
OK
Measure at A-77 motor relay connector
and B-25 ABS-ECU connector.

Disconnect the connector and
measure at the harness side.

Continuity across the following
terminals
Motor relay ABS-ECU
side side
4–49
OK:ConductingNGCheck the following connectors:
A-77, B-25NG
Repair
OK
Measure at A-77 motor relay connector
and A-22 hydraulic unit connector.

Disconnect the connector and
measure at the harness side.

Continuity across the following
terminals
Motor relay Hydraulic
side unit side
4–12
OK:ConductingNGCheck the following connectors:
A-22, A-77NG
Repair
OK
Measure at A-77 motor relay connec-
tor.

Disconnect the connector and
measure at the harness side.

Voltage across 5 and body ground
OK:Battery voltageNGCheck the following connector:
A-77NG
Repair
Check the motor relay.NGReplace the motor relay.