1998 MITSUBISHI LANCER EVOLUTION IV sensor

ABS – Troubleshooting35B-3
2. INSPECTION PROCEDURE FOR DIAGNOSTIC TROUBLE CODES
Code Nos.11, 12, 13 and 14: Wheel speed sensor
(open circuit or short circuit)Probable cause
Code Nos.21, 22, 23 and 24: Wheel speed sensor
Code Nos 11, 12, 13 and 14 are output if the ABS-ECU detects an open circuit or
short-circuit in the (+) wire or (–) wire in any one of the four wheel speed sensors.
Malfunction of wheel speed sensor

Malfunction of wiring harness or connector

Malfunction of ABS-ECU
Code Nos.21, 22, 23 and 24 are output in the following cases.

When there is no input from any one of the four wheel speed sensors when travelling
at 8 km/h or more, even though open circuit can not be verified.

When a chipped or blocked-up ABS rotor is detected and if the anti-lock system
operates continuously because a malfunctioning sensor or a warped ABS rotor
is causing sensor output to drop.
Malfunction of wheel speed sensor

Malfunction of wiring harness or connector

Too much gap between the sensor and the rotor

Malfunction of ABS-ECU

Malfunction of wheel bearing
NG
Check the harness wire, and repair
if necessary.

Between each wheel speed sensor
and ABS-ECU
NG
Replace the ABS-ECU.
OK
Check the trouble symptom.
OK
Check the following connector:
B-24NG
Repair
NG
Repair
OK
Wheel bearing check
OK
ABS rotor check
OK
Wheel speed sensor output voltage
check (Refer to P.35B-17.)NGWheel speed sensor checkNG
Replace
OK
Check the following connectors:
B-24, B-52, B-17, A-26, A-50, D-04,
D-14, D-19OKCheck the trouble symptom.
OK
Measure at the ABS-ECU connector
B-24.

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

Resistances between 8 and 21,
10 and 19, 7 and 20, 9 and 22
OK:1.4 – 1.8 kΩNGWheel speed sensor check
(Refer to P.35B-29.)NG
Replace
Wheel speed sensor installation checkNG
Replace
NG
Replace

ABS – Troubleshooting35B-4
Code No.15: Wheel speed sensor (abnormal output
signal)Probable cause
This code is output when there is an abnormality in the output signal from any one
of the four wheel speed sensors while driving (except for an open circuit or short
circuit).
The four vehicle tires are of different sizes

Malfunction of wheel speed sensor

Malfunction of wiring harness or connector

Malfunction of ABS-ECU

Malfunction of wheel bearing
OK
Check the harness wire, and repair
if necessary.

Between each wheel speed sensor
and ABS-ECU
OK
Wheel bearing checkNG
Replace the ABS-ECU.
OK
ABS rotor checkNG
RepairOK
Check the trouble symptom.
OK
Check the following connector:
B-24NG
Repair
OK
Check the trouble symptom.
OK
Wheel speed sensor output voltage
check (Refer to P.35B-17.)NGWheel speed sensor checkNG
Replace
YES
Wheel speed sensor installation checkNG
Repair
Are the sizes of all four tires identical?NOEquip the vehicle with tires of identical
sizes.
NG

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-10
Code No. 71: Acceleration sensor (lateral acceleration)
systemProbable cause
This code is output under either of the following conditions:

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

The acceleration sensor (lateral acceleration) harness is open- or short-circuited.
Defective acceleration sensor (lateral acceleration)

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 (lateral accelera-
tion) and ABS-ECU.
OK
Check the trouble symptom.NGCheck and repair the harness between
general-purpose fuse No. 6 and
acceleration sensor (lateral accelera-
tion).
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 17 and 18
OK:2.4 – 2.6 V
(horizontal position)NGCheck the following connectors:
B-24, D-32, B-52NG
Repair
NG
Check the harness between accelera-
tion sensor (lateral acceleration) and
ABS-ECU.NG
Repair
OK
Check the trouble symptom.
OK
Check the acceleration sensor (lateral
acceleration). (Refer to P.35B-17.)NG
Replace
(1) NGCheck the following connectors:
D-32, B-49, B-75NG
Repair
Check the following connector:
D-32, B-49, B-75NG
Repair
(2) NG
Measure at D-32 acceleration sensor
(lateral 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-14
INSPECTION PROCEDURE 4
When the ignition key is turned to “START”, the ABS
warning lamp does not illuminate.
Probable cause
The ABS-ECU is powered through IG2 which is turned off when the ignition key
is in START position. The ABS warning lamp is powered through IG1 which is not
turned off even when the ignition key is in START position. So the cause must be
a defective circuit on valve relay side.
Malfunction of wiring harness or connector

Malfunction of valve relay
OK
Check the trouble symptom.NGCheck the harness between the com-
bination meter and valve relay, and
repair if necessary.
OK
Check the motor for operation.NGCheck the harness between the valve
relay and ground, and repair if neces-
sary.
OK
Check the following connector:
A-76NG
Repair
OK
Measure at valve relay connector A-76.

Disconnect the connector and
measure at the harness side.

Disconnect ABS-ECU connector
B-25.

Ignition switch: ON

Voltage between 3 and body
ground
OK:Battery voltageNGCheck the following connectors
and diode:
A-76, B-26NG
Repair
ABS valve relay check.NGReplace the valve relay.
INSPECTION PROCEDURE 5
Brake operation is abnormal
Probable cause
The varies depending on the driving conditions and the road surface conditions, so
problem diagnosis is difficult. However, if a normal diagnosis code is displayed, carry
out the following inspection.
Improper installation of wheel speed sensor

Incorrect sensor harness contact

Foreign material adhering to wheel speed sensor

Malfunction of wheel speed sensor

Malfunction of wheel bearing

Malfunction of hydraulic unit

Malfunction of ABS-ECU
NG
Repair
Hydraulic unit checkOKWheel speed sensor inspection. [Refer to Inspection Procedure
for “when either of diagnosis codes No. 11 to 14 is output” (P.35B-3).]

ABS – Troubleshooting35B-15
5. CHECK AT ABS-ECU TERMINALS
5-1 TERMINAL VOLTAGE LISTING
(1) The voltage is to be measured across each terminal and ground terminal.
(2) Fig. below shows the arrangement of the terminals.
Terminal
No.Check itemCheck requirementNormally
1Solenoid valve OUT (FL) outputIgnition switch: ON (after initial check)Battery voltage
2Solenoid valve OUT (RR) outputIgnition switch: ON (after initial check)Battery voltage
3Solenoid valve IN (RR) outputIgnition switch: ON (after initial check)Battery voltage
4Acceleration sensor (longitudinal
acceleration) inputIgnition switch: ON2.4 – 2.6 V
(horizontal position)
11Wheel speed (FL) outputVehicle stationary1 V or less
Moving forward slowly0 – 5 V
13ABS-ECU power supplyIgnition switch: ONBattery voltage
14Solenoid valve IN (FL) outputIgnition switch: ON (after initial check)Battery voltage
15GroundAt all times0 V
17Acceleration sensor groundAt all times0 V
18Acceleration sensor (lateral
acceleration) inputIgnition switch: ON2.4 – 2.6 V
(horizontal position)
24Wheel speed (RL) outputVehicle stationary1 V or less
Moving forward slowly0 – 5 V
25GroundAt all times0 V
32ABS-ECU backup power supplyAt all timesBattery voltage
33Wheel speed (FR) outputVehicle stationary1 V or less
Moving forward slowly0 – 5 V
34Stop lamp switch inputStop lamp switch: ONBattery voltage
Stop lamp switch: OFF0 V
37Valve relay outputIgnition switch:
ON
When relay is ON0 V
ONWhen relay is OFFBattery voltage
38Motor relay outputIgnition switch:
ON
When motor is energized0 V
ONWhen motor is deenergizedBattery voltage
40Solenoid valve OUT (RL) outputIgnition switch: ON (after initial check)Battery voltage
41Solenoid valve OUT (FR) outputIgnition switch: ON (after initial check)Battery voltage
42GroundAt all times0 V

ABS – Troubleshooting35B-16
Terminal
No.Normally Check requirement Check item
44Wheel speed (RR) outputVehicle stationary1 V or less
Moving forward slowly0 – 5 V
48Valve relay monitor inputIgnition switch: ON (after initial check)Battery voltage
49Motor relay monitor outputIgnition switch:
ON
When motor is energized0 V
ONWhen motor is deenergizedBattery voltage
50ABS warning lamp outputIgnition switch:
ON
When lamp is offBattery voltage
ONWhen lamp is on0 V
51Solenoid valve IN (RL) outputIgnition switch: ON (after initial check)Battery voltage
52Solenoid valve IN (FR) outputIgnition switch: ON (after initial check)Battery voltage
5-2 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
ABS-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
1 – body groundSolenoid valve OUT (FL) output4.04 – 4.54 Ω
2 – body groundSolenoid valve OUT (RR) output4.04 – 4.54 Ω
3 – body groundSolenoid valve IN (RR) output8.04 – 9.04 Ω
7 – 20Wheel speed sensor (FL) input1.4 – 1.8 kΩ
8 – 21Wheel speed sensor (RR) input1.4 – 1.8 kΩ
9 – 22Wheel speed sensor (RL) input1.4 – 1.8 kΩ
10 – 23Wheel speed sensor (FR) input1.4 – 1.8 kΩ
14 – body groundSolenoid valve IN (FL) output8.04 – 9.04 Ω
15 – body groundGroundConducting
25 – body groundGroundConducting
40 – body groundSolenoid valve OUT (RL) output4.04 – 4.54 Ω
41 – body groundSolenoid valve OUT (FR) output4.04 – 4.54 Ω
42 – body groundGroundConducting
48 – body groundValve relay monitor inputConducting
49 – body groundMotor relay monitor inputConducting
51 – body groundSolenoid valve IN (RL) output8.04 – 9.04 Ω
52 – body groundSolenoid valve IN (FR) output8.04 – 9.04 Ω

ABS – On-vehicle Service / Lateral Acceleration Sensor35B-17
ON-VEHICLE SERVICE
WHEEL SPEED SENSOR OUTPUT VOLTAGE
MEASUREMENT
The EVOLUTION-V has the ABS-ECU connector terminal
arranged as shown at left. Accordingly, the terminals to
measure the output voltage of the wheel speed sensors are
different from EVOLUTION-V.
Follow the conventional procedures except these pick-out
terminals.
Measurement terminals:
Front LHFront RHRear LHRear RH
71098
20232221
LATERAL ACCELERATION SENSOR
INSPECTION
Use the same procedures as those for the conventional
longitudinal acceleration sensor.
ABS-ECU connector harness side
Longitudinal
acceleration
sensor
Lateral acceleration sensor