GENERAL – How to Use Troubleshooting/Inspection Service Points00-10
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, “Check harness between power supply and terminal xx” also includes checking for blown fuses.
For inspection service points when there is a blown fuse, refer to “Inspection Service Points for a Blown
Fuse.”
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 – How to Use Troubleshooting/Inspection Service Points00-13
INSPECTION SERVICE POINTS FOR A BLOWN
FUSE
Remove the fuse and measure the resistance between the
load side of the fuse and the earth. Set the switches of all
circuits which are connected to this fuse to a condition of
continuity. If the resistance is almost 0 Ω at this time, there
is a short somewhere between these switches and the load.
If the resistance is not 0 Ω, there is no short at the present
time, but a momentary short has probably caused the fuse
to blow.
The main causes of a short circuit are the following.
Harness being clamped by the vehicle body
Damage to the outer casing of the harness due to wear
or heat
Water getting into the connector or circuitry
Human error (mistakenly shorting a circuit, etc.)
POINTS TO NOTE FOR INTERMITTENT
MALFUNCTIONS
Intermittent malfunctions often occur under certain conditions,
and if these conditions can be ascertained, determining the
cause becomes simple. In order to ascertain the conditions
under which an intermittent malfunction occurs, first ask the
customer for details about the driving conditions, weather
conditions, frequency of occurrence and trouble symptoms,
and then try to recreate the trouble symptoms. Next, ascertain
whether the reason why the trouble symptom occurred under
these conditions is due to vibration, temperature or some
other factor. If vibration is thought to be the cause, carry
out the following checks with the connectors and components
to confirm whether the trouble symptom occurs.
The objects to be checked are connectors and components
which are indicated by inspection procedures or given as
probable causes (which generates diagnosis codes or trouble
symptoms.)
Gently shake the connector up, down and to the left and
right.
Gently shake the wiring harness up, down and to the
left and right.
Gently rock each sensor and relay, etc. by hand.
Gently shake the wiring harness at suspensions and other
moving parts.
NOTE
If determining the cause is difficult, the flight recorder function
of the MUT-II can also be used.
Battery
Fuse
Load
switch
LoadConnector
inspection0 Ω
MPI – Troubleshooting13-40
INSPECTION PROCEDURE 30
Fan motor relay system (Radiator fan, A/C condenser fan)
Probable cause
The engine-ECU turns on/off the built-in power transistor to control the fan motor
relay.Malfunction of the fan motor relay
Malfunction of the fan motor
Improper connector contact, open or short-circuited
harness wire
Malfunction of engine-ECU
NG
Check the radiator fan circuit.
Check the A/C condenser fan circuit.
(Refer to Electrical Wirings.)
NG
Replace the engine-ECU.
OK
Check trouble symptom.
Measure at the engine-ECU connector B-59.
Disconnect the connector, and measure at the harness side.
Voltage between each of 20 and 21 and earth
(Ignition switch: ON)
OK:System voltage
Short the terminal 21 to earth.
(Ignition switch: ON)
OK:Fan operates at low speed.
Short the terminals 20 and 21 to earth.
(Ignition switch: ON)
OK:Fan operates at high speed.OKCheck the following connector: B-59NG
Repair
MPI – Troubleshooting13-41
INSPECTION PROCEDURE 30
Fan motor relay system (Radiator fan, A/C condenser fan)
Probable cause
The engine-ECU turns on/off the built-in power transistor to control the fan motor
relay.Malfunction of the fan motor relay
Malfunction of the fan motor
Malfunction of thermostat
Improper connector contact, open or short-circuited
harness wire
Malfunction of engine-ECU
NG
Check the engine coolant temperature sensor. (Refer to P.13-10,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE 21.)
OK
Replace the engine-ECU.
NG
MUT-II Data list
21 Engine coolant temperature sensor
OK:The engine coolant temperature agrees with the reading
of MUT-II when measured with the engine idling in warm
condition.OKCheck the thermostat.NG
Replace
OK
Check trouble symptom.
OK
Check the following connector: B-60NG
Repair NG
Check the A/C condenser fan circuit. (Refer to Electrical Wirings.)
NG
Measure at the engine-ECU connector B-60.
Disconnect the connector, and measure at the harness side.
Check the A/C condenser fan for operating condition.
(Ignition switch: ON)
OK:A/C condenser fan is stationary.
Voltage between each of 32 and 34 and earth
(Ignition switch: ON)
OK:System voltage
Short the terminal 32 to earth. (Ignition switch: ON)
OK:A/C condenser fan operates at high speed.
Short the terminal 34 to earth. (Ignition switch: ON)
OK:A/C condenser fan operates at low speed.
Check trouble symptom.
OK
OK
Check the following connector: B-59NG
Repair
Measure at the engine-ECU connector B-59.
Disconnect the connector, and measure at the harness side.
Check the radiator fan for operating condition.
(Ignition switch: ON)
OK:Radiator fan is stationary.
Voltage between each of 20 and 21 and earth
(Ignition switch: ON)
OK:System voltage
Short the terminal 20 to earth.
(Ignition switch: ON)
OK:Radiator fan operates at high speed.
Short the terminal 21 to earth.
(Ignition switch: ON)
OK:Radiator fan operates at low speed.NGCheck the radiator fan circuit. (Refer to Electrical Wirings.)
BODY – General / Keyless Entry System42-2
GENERAL
OUTLINE OF CHANGE
The descriptions of the troubleshooting using on MUT-II tester have been incorporated.
KEYLESS ENTRY SYSTEM
SPECIAL TOOL
ToolNumberNameUse
MB991502MUT-II sub assemblyRecording secret codes
TROUBLESHOOTING
INSPECTION CHART FOR TROUBLE SYMPTOMS
Trouble symptomInspection procedure No.Reference page
None of the doors can be locked or unlocked using the transmitter.142-2
All of the doors can be locked and unlocked using the transmitter,
but the room lamp does not flash or illuminate. (However, the room
lamp operates normally when the doors are opened and closed.)242-4
Secret codes cannot be registered.342-4
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
INSPECTION PROCEDURE 1
None of the doors can be locked or unlocked using the
transmitter.
Probable cause
The cause may be a malfunction of the transmitter, a malfunction of the receiver
or the lock and unlock signals are not being input to the ETACS-ECU.Malfunction of transmitter
Malfunction of receiver
Malfunction of ETACS-ECU
Malfunction of wiring harness or connector
Malfunction of key reminder switch
Malfunction of door switch
NG
To next page
OK
Replace the transmitter battery. (Refer to P.42-7.)
Ye s
Has the secret code been registered properly? *NGRe-register the secret code. (Refer to P.42-8.)
Can the doors be locked and unlocked by the driver’s-side door
key cylinder and lock knob?NoCheck the centre door lock system.
NOTE
*: This should be done if a transmitter or receiver has been replaced, and if a secret code has not
been registered properly.
BODY – Keyless Entry System42-4
INSPECTION PROCEDURE 2
All of the doors can be locked and unlocked using the
transmitter, but the room lamp does not flash or
illuminate. (However, the room lamp operates normally
when the doors are opened and closed.)
Probable cause
If the room lamp operates normally when the doors are opened and closed, the cause
of the problem may be a malfunction of the receiver or a malfunction of the harness
between the room lamp the receiver.Malfunction of receiver
Malfunction of connector or wiring harness
NG
Repair
NG
Check the harness wire between room lamp and receiver, and
repair if necessary.
OK
Replace the receiver.
OK
Check trouble symptoms.
Measure at the receiver connector D-01.
Disconnect the connector, and measure at the harness side.
Voltage between 11 and body earth
OK:System voltageNGCheck the following connectors:
B-80, D-01
INSPECTION PROCEDURE 3
Secret codes cannot be registered.
Probable cause
The cause may be a malfunction of the diagnosis connector, a malfunction of the
power supply or earth circuit of the receiver, a malfunction of the earth circuit or
a malfunction of the diagnosis output circuit.Malfunction of receiver
Malfunction of MUT-II
Malfunction of connector or wiring harness
NG
Repair
NG
Check the harness wire, and repair if necessary.
Between receiver and diagnosis connector
NG
Repair
NG
Check the harness wire, and repair if necessary.
Between fusible link No.1 and diagnosis connector
OK
Check trouble symptoms.NGCheck the harness wire, and repair if necessary.
Between diagnosis connector and earth
Ye s
To next page
NG
Check the following
connectors:
B-22, B-50NG
Repair
OK
Measure at the diagnosis
connector B-22.
Continuity between 4
and body earth
Continuity between 5
and body earth
OK:ContinuityOKReplace MUT-II.
OK
Check trouble symptoms.
No
Measure at the diagnosis
connector B-22
Voltage between 16
and body earth
OK:System voltageNGCheck the following connectors:
B-22, B-49, B-75
OK
Can the MUT-II communicate with other systems?
OK
Check trouble symptoms.
Measure at the diagnosis connector B-22 and the receiver connector
D-01.
Disconnect the connector, and measure at harness side.
Continuity between following terminals:
OK:Continuity
7
B-22, D-01
BODY – SunroofBODY – Sunroof42-9
SUNROOF
SERVICE SPECIFICATIONS
ItemsStandard value
Roof lid glass operating current A (at 20C)7 or less
Sunroof motor clutch slippage torque Nm4.7 – 6.2
SEALANT
ItemSpecified sealant
Rail cover assembly3M ATD Part No.8531 or 3M Part No.8646 or equivalent
TROUBLESHOOTING
INSPECTION CHART FOR TROUBLE SYMPTOMS
Trouble symptomInspection procedureReference page
The sunroof can not be operated when the ignition switch is in
ON position.142-9
The motor does not reverse its direction when a load of 140 N
or more is applied while the sunroof is closing.242-11
The timer does not operate for 30 seconds after the ignition
switch is turned to OFF.342-11
Opening or closing of the sunroof is possible for 30 seconds
after turning the ignition switch to OFF, but the timer function
is not extended when the driver’s side door is opened within this
period.442-11
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
Inspection Procedure 1
The sunroof can not be operated when the ignition switch
is in ON position.
Probable cause
One of the following items may be defective.
Sunroof switch
Sunroof motor
Sunroof-ECU power supply circuit
Earth circuitMalfunction of sunroof switch
Malfunction of sunroof motor
Malfunction of sunroof-ECU
Malfunction of wiring harness or connector
BODY – Sunroof42-11
Inspection Procedure 2
The motor does not reverse its direction when a load of
140 N or more is applied while the sunroof is closing.
Probable cause
The sunroof-ECU monitors the load conditions from the amount of current flowing
to the motor. If more than the constant amount of current is flowing, the direction
of motor operation is reversed to prevent jamming.
If the motor does not reverse direction even when an excessive load is being applied,
the cause may be a malfunction of the sunroof-ECU.Malfunction of sunroof-ECU
Replace the sunroof-ECU.
Inspection Procedure 3
The timer does not operate for 30 seconds after the
ignition switch is turned to OFF.
Probable cause
The sunroof-ECU has a timer function which operates for 30 seconds after the ignition
switch is turned to OFF. If the timer does not operate, the cause may be a malfunction
of the sunroof-ECU or of the wiring harness or connector.Malfunction of sunroof-ECU
Malfunction of wiring harness or connector
Measure at the sunroof-ECU connector
D-10.
Disconnect the connector and
measure at the harness side.
Voltage between 7 and body earth
OK:System voltageNGCheck the following connectors:
B-44, B-76, B-73NG
Repair
OK
Check trouble symptoms.
OK
Replace the sunroof-ECU.
Check the harness wire between fusible
link No.1 and sunroof-ECU, and repair
if necessary. NG
Inspection Procedure 4
Opening or closing of the sunroof is possible for 30
seconds after turning the ignition switch to OFF, but the
timer function is not extended when the driver’s side door
is opened within this period.
Probable cause
The sunroof timer operation period is extended when an on signal is output from
the driver’s-side door switch. Because of this, if the timer operation period is not
extended, the cause may be a malfunction of the door switch input circuit.Malfunction of the front door switch (driver’s side)
Malfunction of sunroof-ECU
Malfunction of wiring harness or connector
Check front door switch (driver’s side)
continuity.NG
Replace
OK
Check the following connectors:
B-44, D-03, D-10NG
Repair
OK
Check trouble symptoms.NGCheck the harness wire between front
door switch (driver’s side) and sunroof-
ECU.NG
Repair
OK
Replace the sunroof-ECU.