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
54-1
CHASSIS
ELECTRICAL
CONTENTS
GENERAL 3. . . . . . . . . . . . . . . . . . . . . . . . . .
BATTERY 3. . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE SPECIFICATION 3. . . . . . . . . . . . . . .
ON-VEHICLE SERVICE 3. . . . . . . . . . . . . . . . . .
IGNITION SWITCH
SYSTEM> 6. . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOL 6. . . . . . . . . . . . . . . . . . . . . . . . .
TROUBLESHOOTING 6. . . . . . . . . . . . . . . . . . . .
IGNITION SWITCH 11. . . . . . . . . . . . . . . . . . . . . .
IGNITION SWITCH AND IMMOBILIZER
SYSTEM
SPECIAL TOOL 13. . . . . . . . . . . . . . . . . . . . . . .
TROUBLESHOOTING 13. . . . . . . . . . . . . . . . . .
IGNITION SWITCH AND IMMOBILIZER
SYSTEM 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COMBINATION METERS 22. . . . . . . . . . . .
SERVICE SPECIFICATIONS 22. . . . . . . . . . . .
SEALANT 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOLS 23. . . . . . . . . . . . . . . . . . . . . .
TROUBLESHOOTING 24. . . . . . . . . . . . . . . . . .
CONTINUED ON NEXT PAGE
WARNINGS REGARDING SERVICING OF SUPPLEMENTAL RESTRAINT SYSTEM (SRS) EQUIPPED VEHICLES
WARNING!
(1) The service personnel must thoroughly review this manual, and especially its GROUP 52B – Supplemental Restraint
System (SRS) before beginning any service or maintenance of any component of the SRS or any SRS-related
component.
(2) When removing or installing the components indicated in the table of contents by an astarisk (*), use utmost care so
as not to apply any strong shock to SRS components.
NOTE
The SRS includes the following components: SRS-ECU, SRS warning lamp, air bag module, clock spring and interconnecting
wiring. Other SRS-related components (that may have to be removed/installed in connection with SRS service or maintenance) are
indicated in the table of contents by an asterisk (*).
CHASSIS ELECTRICAL – Ignition SwitchCHASSIS ELECTRICAL – Ignition Switch54-6
IGNITION SWITCH
SPECIAL TOOL
ToolNumberNameUse
MB991502MUT-II sub
assemblyETACS-ECU input signal checking
TROUBLESHOOTING
DIAGNOSIS FUNCTION
INPUT SIGNAL INSPECTION POINTS
Refer to Group 00 – How to Use Troubleshooting / Inspection
Service Points.
INSPECTION CHART FOR TROUBLE SYMPTOMS
Trouble symptomsInspection
procedureReference page
Communication with
MUTIIis impossible
Key hole illumination lamp remains illuminated.154-7
MUT-II is impossible.
Even if driver’s side door is opened, key hole
illumination lamp does not illuminate.254-7
While key hole illumination lamp is illuminated,
ignition key is turned to the ON position but key hole
illumination lamp does not switch off. (However, it
switch off after 10 seconds.)354-8
Key reminder warning
buzzer systemWhile the key reminder warning buzzer is sounding,
the ignition key is turned to the ON position but the
sound dose not stop. (However, it stops when the
driver’s side door is closed.)354-8
The key reminder warning buzzer dose not stop
sounding even if the key is removed. (However, it
stops when the driver’s side door is closed.)454-9
The key reminder warning buzzer does not sound
ever if the driver’s side door is opened while the key
is still inserted. (However, the ignition key should be
in the OFF position.)554-10
NOTE
If every input signal can not be checked with the MUT-II, a diagnosis circuit system failure is probably
the cause.
CHASSIS ELECTRICAL – Ignition Switch54-7
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
Inspection Procedure 1
Key hole illumination lamp remains illuminated.
Probable cause
The cause is probably a harness short or a defective ETACS-ECU or buzzer ECU.Malfunction of harness wire
Malfunction of ETACS-ECU
Malfunction of buzzer ECU
Disconnect the ignition key cylinder illumination lamp connector
B-84 and measure the continuity:
Between 4 and body earth
OK:ConductingNGCheck the harness wire between the ignition key cylinder illumination
lamp and junction block, and repair if necessary.
OK
Replace the ETACS-ECU or buzzer ECU.
Inspection Procedure 2
Even if driver’s side door is opened, key hole illumination
lamp does not illuminate.
Probable cause
The cause is probably a defective key hole illumination lamp circuit system, or a
defective driver’s side door switch input circuit system if the ignition key reminder
warning buzzer is also faulty.Malfunction of driver’s side door switch
Malfunction of bulb
Malfunction of connector
Malfunction of harness wire
Malfunction of ETACS-ECU
Malfunction of buzzer ECU
OK
Replace ETACS-ECU or buzzer ECU.
MUT-II Pulse check
Driver’s side door switch input signal
OK:The MUT-II buzzer sounds once
when the driver’s side door switch
is ON.NG
Driver’s side door switch input circuit
system inspection (Refer to Inspection
Procedure 6 on P.54-10.)
OK
Disconncet the key hole illumination
lamp connector B-84, and measure at
the harness side.
Voltage between 3 and body earth
OK:System voltageNGCheck the following connectors:
B-49, B-75, B-73NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between
ETACS-ECU or buzzer ECU and fusible
link 1, and repair if necessary.
Vehicle with buzzer ECU
Remove ETACS-ECU or buzzer ECU
from junction block, and measure at the
junction block connector B-79
Ignition key cylinder illumination
lamp connector connected
Voltage between 12 and body earth
OK:System voltage
OK
OK
NG
Check the following connectors:
B-84, B-49, B-75, B-73NG
Repair
OK
Check trouble symptom.
Check the harness wire between the
ignition key cylinder illumination lamp
and fusible link 1, and repair if neces-
sary.
NG
CHASSIS ELECTRICAL – Ignition Switch54-8
Inspection Procedure 3
While key hole illumination lamp is illuminated, ignition
key is turned to the ON position but key hole illumination
lamp does not switch off. (However, it switch off after 15
seconds.)
Probable cause
While the key reminder warning buzzer is sounding, the
ignition key is turned to the ON position but the sound
dose not stop. (However, it stops when the driver’s side
door is closed.)
The cause is probably a malfunction of the ignition switch input circuit, ETACS-ECU
or buzzer ECU. Furthermore, if there is a malfunction of a multipurpose fuse, the
cause may also be a short circuit in a harness.Malfunction of fuse
Malfunction of connector
Malfunction of harness
Malfunction of ETACS-ECU
Malfunction of buzzer ECU
OK
Replace ETACS-ECU.
MUT-II Pulse check
Ignition switch input inspection
OK:The MUT-II buzzer sounds once
when the ignition key is turned
to the ON from OFF position.
NG
Disconnect the junction block connector
B-76 and measure at the harness side.
Voltage between the terminal No.
8 and body earth.
OK:System voltageNGCheck the following connectors:
B-76, B-79Repair
OK
Check trouble symptom.
Replace the buzzer ECU.
Replace ETACS-ECU.
Check the harness wire between the
ignition switch (IG1) and junction block
and repair if necessary.
OK
Junction block harness continuity check
NG
NOTE
The stop indicated with a dotted line
applies only to vehicles with buzzer
ECU. OK
NG
Replace NG
CHASSIS ELECTRICAL – Ignition Switch54-9
Inspection Procedure 4
The key reminder warning buzzer dose not stop sounding
even if the key is removed. (However, it stops when the
driver’s side door is closed.)
Probable cause
The cause is probably a malfunction of the key reminder switch input circuit system,
or a malfunction of ETACS-ECU, or a malfunction of buzzer ECU.Malfunction of key reminder switch
Malfunction of connector
Malfunction of harness
Malfunction of ETACS-ECU
Malfunction of buzzer ECU
YES
Check the following connectors.
B-84, B-75NG
NG
Inspect the harness between the key
reminder switch and ETACS-ECU or
buzzer ECU, and repair if necessary.
OK
Check trouble symptom.
OK
Replace the ETACS-ECU or the buzzer
ECU.OK
NG
Key reminder switch continuity inspec-
tion (Refer to P. 54-12.)NG
Replace
MUT-II Pulse check
Ignition switch input inspection
OK:The MUT-II buzzer sounds once
when the ignition key is removed
from the key cylinder.OKReplace the ETACS-ECU.
Replace
OK
Check trouble symptom
OK
Disconnect the key reminder switch
connector and connect the terminal No.
5 to the body earth. Does the buzzer
stop sounding?NOCheck the following connectors.
B-84, B-75, B-79NG
Repair
Check the harness wire between the
key reminder switch and the body earth
and repair if necessary.
Replace the buzzer ECU.
NOTE
The stop indicated with a dotted line
applies only to vehicles with buzzer
ECU.