GENERAL ± How to Use Troubleshooting/Inspection Service Points00-9
HOW TO USE THE INSPECTION PROCEDURES
The causes of a high frequency of problems occurring in electronic circuitry are generally the connectors,
components, the ECU and the harnesses between connectors, in that order. These inspection procedures
follow this order, and they first try to discover a problem with a connector or a defective component.
Indicator does not turn on or off even if control
mode switch is pressed.
Indicator switch should not be illuminated is
illuminated.Probable cause
OK
OK
OK
Measure at switch connector A-44
Disconnect the connector, and measure at the harness
side.
Voltage between terminal 6 ± earth and terminal 8 ±
earth
OK:Approx. 5V
OK
NG
Check the following connector. A-44
Repair
OK
Check trouble symptom.
Replace the ECS-ECU.
In the above cases, the ECS switch circuit is defective or the indicator
circuit is defective.
CHECKING PROCEDURE 4
2. Indicates inspection carried out using the
MUT-II.
Indicates the operation and inspection proce-
dures.
Indicates the OK judgement conditions.
3. Detailed inspection procedures (methods)
such as component inspection and circuit
inspection are listed on a separate page, and
are given here for reference.
5. Inspect the contact condition at each connector terminal.
(Refer to Connector Inspection Service Points.)
The connector position can be located in the wiring diagram in the
electrical wiring manual by means of this symbol.
Caution
After carrying out connector inspection, always be sure to
reconnect the connector as it was before.
6. Confirm that there are trouble symptoms. If trouble symptoms have
disappeared, the connector may have been inserted incorrectly and the
trouble symptom may have disappeared during inspection.
If it seems that trouble symptoms still remain, proceed to the next page of
instructions.
7. If trouble symptoms still remain up to this stage, there is a possibility that there is an
open or short circuit in the harness between the connectors, so check the harness.
Alternatively, the cause may be a defective ECU, so try replacing the ECU and check
if the trouble symptom disappears.
NGECU switch component inspection (Refer to P.3-44.)
NG
1. Comments on the diagnosis code or trouble
symptom above.
MUT-II Data list
17 Control mode selection switch
OK:Voltage changes between approx. 0V approx.
2.5V approx. 5V when the switch is operated.
4. Indicates voltage and resistance to be measured at a particular
connector.
(Refer to Connector Measurement Service Points.)
The connector position can be located in the wiring diagram in the
electrical wiring manual by means of this symbol.
Indicates operation and inspection procedures, inspection terminals
and inspection conditions.
Indicates the OK judgement conditions.
HARNESS INSPECTION
Check for an open or short circuit in the harness between the terminals which were defective according
to the connector measurements. Carry out this inspection while referring to the electrical wiring manual.
Here, ªCheck harness between power supply and terminal xxº also includes checking for blown fuses.
For inspection service points when there is a blown fuse, refer to ªInspection Service Points for a Blown
Fuse.º
MEASURES TO TAKE AFTER REPLACING THE ECU
If the trouble symptoms have not disappeared even after replacing the ECU, repeat the inspection procedure
from the beginning.
GENERAL ± Supplemental Restraint System (SRS)00-31
Harness connector
(No. of terminals,
colour)SDU
terminal
No.Destination of harnessCorrective action
2 pins, red1, 2Body wiring harness Clock springReplace clock spring
±3, 4±±
±5, 6±±
14 pins, red7, 8±±
9Body wiring harness Diagnosis connectorCorrect or replace each
wiring harness
10Body wiring harness Front wiring harness
Ignition switch (ST)
wiring harness
11Body wiring harness Junction block (fuse No. 11)
12Body wiring harness Junction block (fuse No. 10)
13Body wiring harness Combination meter (SRS
warning lamp)
14±±
15Body wiring harness Front wiring harness
Front impact sensor (+) (R.H.)Sensor cable* installa-
tion procedures
(Refer to GROUP 52B )16Body wiring harness Front wiring harness
Front impact sensor (+) (L.H.)(Refer to GROUP 52B.)
17Body wiring harness Front wiring harness
Front impact sensor (±) (L.H.)
18Body wiring harness Front wiring harness
Front impact sensor (±) (R.H.)
19, 20Body wiring harness EarthCorrect or replace each
wiring harness
NOTE
The sensor cable marked with * is available as service part.
7. SRS components should not be subjected to heat over 93C, so remove the SRS-diagnosis unit,
air bag module, clock spring and front impact sensors before drying or braking the vehicle after painting.
8. Whenever you finish servicing the SRS, check warning lamp operation to make sure that the system
functions properly. (Refer to GROUP 52B ± SRS Maintenance.)
9. Make certain that the ignition switch is OFF when the MUT-II is connected or disconnected.
10. If you have any questions about the SRS, please contact your local distributor.
NOTE
SERIOUS INJURY CAN RESULT FROM UNINTENDED AIR BAG DEPLOYMENT, SO USE ONLY
THE PROCEDURES AND EQUIPMENT SPECIFIED IN THIS MANUAL.
ABS <2WD> ± Troubleshooting35B-7
INSPECTION PROCEDURE FOR DIAGNOSIS CODES
Code No. 11, 12, 13, 14 Wheel speed sensor open circuit
or short circuitProbable cause
Code No. 21, 22, 23, 24 Wheel speed sensor abnormal
The ABS-ECU determines that an open circuit or short circuit occurs in more than
one line of wheel speed sensors.Malfunction of wheel speed sensor
Malfunction of wiring harness or connector
Malfunction of ABS-ECU
These codes are output at the following times:
When an open circuit cannot be found, but more than one wheel speed sensor
does not output any signal during driving at 8 km/h or higher.
When a chipped or plugged-up rotor tooth, etc. is detected.
When the sensor output drops and anti-lock control is continuously carried out
due to a defective sensor or a warped rotor.Malfunction of wheel speed sensor
Malfunction of rotor
Malfunction of wheel bearing
Malfunction of wiring harness or connector
Malfunction of ABS-ECU
NG
Replace the ABS-ECU.
OK
Check trouble symptoms.
OK
Check the following connector.
C-62NG
RepairOK
Wheel bearing check. (Refer to GROUP
26 and 27 ± On-vehicle Service.)
OK
Rotor check. (Refer to P.35B-40.)NGReplace the rotor.
OK
Wheel speed sensor output voltage
check. (Refer to P.35B-24.)NGWheel speed sensor check. (Refer to
P.35B-39.)NGReplace the wheel speed sensor.
OK
Measure at the ABS-ECU connectors
C-62
Disconnect the connector and
measure from the harness side.
Resistance values between 10 ± 23,
7 ± 20, 8 ± 21 and 9 ± 22.
OK: 1.2 ± 1.4 kWNGCheck the following connectors.
A-01, A-07, F-01, F-16, D-01 and C-02NG
Repair
Wheel speed sensor installation check.NG
Repair
OK
Check trouble symptoms.NGCheck the harness wire between each
wheel speed sensor and ABS-ECU, and
repair if necessary.
ABS <2WD> ± Troubleshooting35B-8
Code No. 15 Wheel speed sensor (Abnormal output signal)Probable cause
A wheel speed sensor outputs an abnormal signal (other than an open or short-circuit).Improper installation of wheel speed sensor
Malfunction of wheel speed sensor
Malfunction of rotor
Malfunction of wheel bearing
Malfunction of wiring harness or connector
Malfunction of ABS-ECU
NG
Replace the ABS-ECU.
OK
Check trouble symptoms.
OK
Wheel bearing check. (Refer to GROUP
26 and 27 ± On-vehicle Service.)OKCheck the harness wire between each
wheel speed sensor and ABS-ECU, and
repair if necessary.
OK
Rotor check. (Refer to P.35B-40.)NGReplace the rotor.
OK
Check the following connector.
C-62NG
Repair
OK
Wheel speed sensor output voltage
check (Refer to P.35B-24.)NGWheel speed sensor check. (Refer to
P.35B-39.)NGReplace the wheel speed sensor.
Wheel speed sensor installation check.NG
Repair
Code No. 16 Power supply systemProbable cause
The voltage of the ABS-ECU power supply drops lower or rises higher than the specified
value. If the voltage returns to the specified value, this code is no longer output.Malfunction of wiring harness or connector.
Malfunction of ABS-ECU
Caution
If battery voltage drops or rises during inspection, this code will be output as well. If the voltage
returns to standard value, this code is no longer output.
Before carrying out the following inspection, check the battery level, and refill distilled water if
necessary.
OK
Check the battery.
OK
Check trouble symptoms.NGCheck the harnes wire between the igni-
tion switch and the ABS-ECU, and repair
if necessary.
OK
Check trouble symptoms.NGReplace the ABS-ECU.
OK
Check the following connector.
C-62NG
Repair
Measure at the ABS-ECU connector
C-62.
Disconnect the connector and
measure at the harness side.
Start the engine. Voltage between
13 ± Body earth
OK:System voltageNGCheck the following connectors.
C-88, C-86 and C-02NG
Repair
ABS <2WD> ± Troubleshooting35B-10
Code No. 41, 42, 43 Solenoid valveProbable cause
The ABS-ECU always monitors the solenoid valve drive circuit. It determines that
there is an open or short-circuit in the solenoid coil or in a harness: When no current
flows in the solenoid even though the ABS-ECU turns on it, and vice versa.Malfunction of wiring harness
Malfunction of hydraulic unit
Malfunction of ABS-ECU
NG
Check the harness between the hydrau-
lic unit and ABS-ECU, and repair if nec-
essary.
OK
Check trouble symptoms.
Measure at hydraulic unit connector
A-09.
Disconnect the connector and
measure at the harness side.
Resistance values between the
following terminals
1-5, 2-5, 3-5
OK: 5.0 W
6-5, 7-5, 8-5
OK: 2.2 WNGReplace the hydraulic unit.
OK
Measure at hydraulic unit connector
A-09 and ABS-ECU connectors C-62
and C-64.
Disconnect the connector and
measure at the harness side.
Continuity between the following
terminals
OK:Continuity
HU side
ABS-ECU
side (C-64)
HU side
ABS-ECU
side (C-62)NGCheck the following connectors.
A-09, C-62 and C-64NG
Repair
OK
Measure at hydraulic unit connector
A-09 and valve relay connector A-39.
Disconnect the connector and
measure at the harness side.
Continuity between the following
terminals
OK:Continuity
HU side
Valve relay sideNGCheck the following connector and
diode.
A-09 and A-39NG
Repair
OK
Check trouble symptoms.NGCheck the harness between the hydrau-
lic unit and valve relay, and repair if nec-
essary.
OK
Check the following connectors.
C-62 and C-64NG
Repair
OK
Check trouble symptoms.NGReplace the ABS-ECU. 1
52
2
14 6
41
3
37
18
2
5
310
3
ABS <2WD> ± Troubleshooting35B-11
Code No. 51 Valve relayProbable cause
When the ignition switch is turned to ON, the ABS-ECU switches the valve relay
off and on during the initial check. In that way, the ABS-ECU compares the signals
sent to the valve relay with the voltage in the valve power monitor line. That is how
to check if the valve relay is operating normally. The ABS-ECU always checks if
current flows in the valve power monitor line, too. It determines that there is an open
circuit when no current flows. If no current flows in the valve power monitor line,
this diagnosis code is output.Malfunction of valve relay
Malfunction of wiring harness or connector
Malfunction of ABS-ECU
Malfunction of hydraulic unit
NOTE
Whenever reading the diagnosis codes using the ABS warning lamp (Refer to GROUP 00 ± How to
Use Troubleshooting/Inspection Service Points), this diagnosis code will be output. That is not a malfunction
but because the valve relay connector is disconnected. After repairing all other malfunctions, connect
the valve relay connector again to check the valve relay. Then check that the ABS warning lamp does
not illuminate. If it illuminates, the valve relay may be defective. So carry out the following procedure.
Valve relay check. (Refer to P. 35B-28.)NGReplace the valve relay.
OK
Measure at valve relay connector A-39.
Disconnect the connector and
measure at the harness side.
Voltage between 6 ± body earth
OK:System voltageNGCheck the harness between fusible link
No. 11 and valve relay, and repair if nec-
essary.
OK
Measure at ABS-ECU connector C-62
and C-64.
Disconnect the connector and
measure at the harness side.
Resistance between 26 ± 37
OK:60 ± 120 WNGCheck the following connector.
A-39OKCheck trouble symptoms.
NG
Check the harness between valve relay
and ABS-ECU, and repair if necessary.
OK
Measure at ABS-ECU connector C-64.
Disconnect the connector and
measure at the harness side.
Continuity between 48 ± body earth
OK:ContinuityNGCheck the harness between the valve
relay and ABS-ECU, and repair if neces-
sary.
OK
Check the following connector.
C-64OKCheck trouble symptoms.NGReplace the ABS-ECU.
ABS <2WD> ± Troubleshooting35B-12
Code No. 53 Motor relay, motorProbable cause
These codes are output at the following times:
When the motor relay is on but no signal is input to the motor monitor line (motor
is not operating, etc.)
When the motor relay is off but a signal is input to the motor monitor line for 5 seconds
or more (motor continues operating, etc.)
When the motor relay does not operateMalfunction of motor relay
Malfunction of wiring harness or connector
Malfunction of hydraulic unit
Malfunction of ABS-ECU
Caution
Because force-driving of the motor by means of the actuator test will drain the battery, the engine
should be started and left to run for a while after testing is completed.
NG
Repair
MUT-II Actuator test
Is the sound of the motor operating
heard for items 01 ± 03 only?Ye sCheck the harness between the hydrau-
lic unit and ABS-ECU, and repair if nec-
essary.
No
ABS motor relay check. (Refer to
P.35B-28.)NGReplace the motor relay.
OK
Measure at motor relay connector A-38.
Disconnect the connector and
measure at the harness side.
Voltage between 5 ± body earth
OK:System voltageNGCheck the harness between fusible link
No. 11 and ABS motor relay, and repair
if necessary.
OK
Measure at ABS-ECU connectors C-62
and C-64.
Disconnect the connector and
measure at the harness side.
Resistance between 26 ± 38
OK:72 ± 88 WNGCheck the following connector.
A-38
OK
Check trouble symptoms.NGCheck the harnesses between motor
relay and ABS-ECU, and repair if
necessary.
OK
Measure at ABS-ECU connector C-64.
Disconnect the connector and
measure at the harness side.
Continuity between 49 ± body earth
OK:ContinuityNGCheck the harness between the
hydraulic unit and ABS-ECU, and repair
if necessary. Motor earth, repair if
necessary.
OK
Motor operation check. (Refer to
P.35B-27.)NGReplace the hydraulic unit.
OK
Check the following connector.
C-64NG
Repair
OK
Check trouble symptoms.NGReplace the ABS-ECU.
ABS <2WD> ± Troubleshooting35B-15
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
Inspection Procedure 1
Communication with MUT-II is not possible.
(Communication with all systems is not possible.)
Probable cause
The reason is probably a defect in the power supply system (including earth) for
the diagnosis line.Malfunction of connector
Malfunction of harness
Refer to GROUP 13A ± Troubleshooting.
Inspection Procedure 2
Communication with MUT-II is not possible.
(Communication with ABS only is not possible.)
Probable cause
When communication with the MUT-II is not possible, the cause is probably an open
circuit in the ABS-ECU power circuit or an open circuit in the diagnosis output circuit.Blown fuse
Malfunction of wiring harness or connecter
Malfunction of ABS-ECU
OK
Check trouble symptoms.NGReplace the ABS-ECU.
OK
Check the following connectors.
C-62 and C-64NG
Repair
OK
Check trouble symptoms.NGCheck the harness wire between the
ignition switch and the ABS-ECU, and
repair if necessary.
OK
Measure at ABS-ECU connectors C-62
and C-64
Disconnect the connector and
measure at the harness side.
Continuity between 4, 15, 16, 25
(C-62), 42 (C-64) ± body earth
OK:ContinuityNG
OK
Measure at ABS-ECU connector C-62
Disconnect the connector and
measure at the harness side.
Ignition switch: ON
Voltage between 13 ± body earth
OK:System voltageNGCheck the following connectors.
C-88, C-86 and C-02NG
Repair
OK
Check trouble symptoms.NGCheck the harness between the ABS-
ECU and diagnosis connector, and re-
pair if necessary.
Measure at diagnosis connector C-35
and ABS-ECU connector C-64
Disconnect the connector and
measure at the harness side.
Continuity between the following
terminals
OK:Continuity
ABS-ECU side
Diagnosis connector sideNGCheck the following connector.
C-02NG
Repair
Repair 47
1367