ENGINE AND EMISSION CONTROL -Auto-cruise Control System17-19
Inspection Procedure 9
Auto-cruise control switch input system check
NG
Check the harness between the auto-cruise control switch and
the throttle valve controller, and repair if necessary.
OK
NG
Repair
OK
Check trouble symptom. NG
OK
Auto-cruise control switch check (Refer to P.17-29.)NG
Replace
NG OKClock spring check (Refer to GROUP 52B.)
Repair
OK
NG
Repair
NG
OK
Check trouble symptom.
NG
Check the harness between the J/B and the auto-cruise control
switch, and repair if necessary.
Check the following connectors:
D-210, D-31, D-205, D-205-2, D-205-3
OK
Check trouble symptom.
NG
Repair
NG
Replace the throttle valve controller.NG
Measure at the throttle valve controller connector D-11.
DDisconnect the connector and measure at the harness side.
DIgnition switch and auto-cruise control MAIN switch: ON
DVoltage between terminal 12 and earth
OK:System voltage
Measure at the auto-cruise control switch connector D-205-3.
DDisconnect the connector and measure at the harness side.
DIgnition switch: ON
DVoltage between terminal 1 and earth
OK:System voltage
NG
Check the harness between the auto-cruise control switch and
the throttle valve controller, and repair if necessary.
OK
Check trouble symptom.
Check the following connectors:
D-205-3, D-205-2, D-205, E-10, D-11
Measure at the throttle valve controller connector D-11.
DDisconnect the connector and measure at the harness side.
DIgnition switch and auto-cruise control MAIN and CANCEL
switch: ON
DVoltage between terminal 10 and earth
OK:System voltageCheck the following connectors:
D-205-3, D-205-2, D-205, E-10, D-11
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ENGINE AND EMISSION CONTROL -Auto-cruise Control SystemENGINE AND EMISSION CONTROL -Auto-cruise Control System17-20
INSPECTION CHART FOR TROUBLE SYMPTOMS <4M4>
Trouble symptomInspection
procedure No.Reference page
Communication with MUT-IIis not possible.117-20
Auto-cruise control isEven if brake pedal is depressed217-21
not cancelled.
Even if clutch pedal is depressed
Even if select lever is set to N range417-22
Even if CANCEL switch is set to ON517-22
Auto-cruise control cannot be set.617-22
Hunting (repeated acceleration and deceleration) occurs at the set vehicle speed.717-23
When the MAIN switch of the auto-cruise control switch is turned ON, the
auto-cruise control indicator lamp does not illuminate. (However, the auto-cruise
control system is normal.)817-23
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS <4M4>
Inspection Procedure 1
Communication with MUT-II
is not possible.
Probable cause
If the MUT-
IIcan not also communicate with the systems other than the diesel fuel
system, the diagnosis line circuit may be defective.
If the MUT-
IIcan not communicate with only the diesel fuel system and the auto-cruise
control system, the harness wire between the engine-ECU and the diagnosis connector,
may be defective.
In addition, if the MUT-
IIcan not communicate with only the auto-cruise control system,
the auto-cruise control switch may be defective.DMalfunction of the connector
DMalfunction of the harness
DMalfunction of the auto-cruise control switch
DMalfunction of the engine-ECU
NORefer to GROUP 13C - Troubleshooting (Inspection procedure 2).
Can the MUT-
IIcommunicate with the other systems (except the
diesel fuel system)?NORefer to GROUP 13C - Troubleshooting (Inspection procedure 1).
YES
Can the MUT-
IIcommunicate with the diesel fuel system?
YES
Check the auto-cruise control switch input signal.
(Refer to Inspection Procedure 9, P.17-24.)
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ENGINE AND EMISSION CONTROL -Auto-cruise Control System17-21
Inspection Procedure 2
Even if brake pedal is depressed, auto-cruise control is
not cancelled.
Probable cause
The cause is probably a malfunction of stoplampswitch or a malfunction of stop
lampcircuit.DMalfunction of the stoplampswitch
DMalfunction of the connector
DMalfunction of the harness
DMalfunction of the engine-ECU
RepairIs the stoplampswitch installed correctly?NO
YES
Follow the INSPECTIONPROCEDURE FOR DIAGNOSIS CODE
No. 22 - Stoplampswitch system. (Refer to P.17-14.)
Inspection Procedure 3
Even if clutch pedal is depressed, auto-cruise control is
not cancelled.
Probable cause
The cause is probably a malfunction of clutch switch or clutch switch circuit.DMalfunction of the clutch switch
DMalfunction of the connector
DMalfunction of the harness
DMalfunction of the engine-ECU
Clutch switch check (Refer to GROUP 21.)NG
Replace
OK
Measure at clutch switch connector D-137.
DDisconnect the connector and measure at the harness side.
DContinuity between terminal 1 and body earth
OK:ContinuityNGCheck the following connector:D-137
NG
Repair OK
Check trouble symptom.
OK
Check trouble symptom.
OK
Check the following connectors:
D-111, E-10, D-26, D-137
D-111, E-10, D-124, D-137
RepairNG
Check the harness between the clutch switch and body earth,
and repair if necessary.
NG
Check the harness between the throttle valve controller and clutch
switch.
NG
Replace the engine-ECU. OKCheck trouble symptom.NG
Repair
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ENGINE AND EMISSION CONTROL -Auto-cruise Control System17-22
Inspection Procedure 4
Even if select lever is set to N range, auto-cruise control
is not cancelled.
Probable cause
The cause is probably a defective inhibitor switch circuit.DMalfunction of the connector
DMalfunction of the harness
DMalfunction of the engine-ECU
OK
Check trouble symptom.
Check the following connectors:D-113, E-113, C-05NG
Repair
NG
Check the harness between the engine-ECU and inhibitor switch.
NG
Replace the engine-ECU. OKCheck trouble symptom.NG
Repair
Inspection Procedure 5
Even if auto-cruise control CANCEL switch is set to ON,
auto-cruise control is not cancelled.
Probable cause
The cause is probably an open-circuit in the circuit inside the CANCEL switch.DMalfunction of the auto-cruise control switch
Replace the auto-cruise control switch.
Inspection Procedure 6
Auto-cruise control cannot be set.
Probable cause
The cause is probably that the fail-safe function is cancelling auto-cruise control.
In this case, the MUT-
IIcan be used to check the trouble symptoms in each system
by inspecting the diagnosis codes.
The MUT-
IIcan also be used to check if the circuits of each input switch are normal
or not by inspecting the data list.DMalfunction of the auto-cruise control switch
DMalfunction of the harnesses
DMalfunction of the connectors
DMalfunction of the engine-ECU
Check trouble symptoms.
Can the auto-cruise control system communicate with the MUT-
II?NOFollow inspection procedure for trouble symptom No.1.
(Refer to P.17-20.)
YES
MUT-
IISelf-Diag code
(1) Is a diagnosis code regarding the auto-cruise control
system output?
(2) Is a diagnosis code regarding the diesel fuel system
output?(1) YESINSPECTION CHART FOR DIAGNOSIS CODES (Refer to
P.17-13.)
NO
MUT-
IIData list
02 SET switchNGCheck the control switch input system. (Inspection procedure 9,
P.17-24.)
OK
MUT-
IIData list
07 Clutch switch
NG
NO
Replace the throttle valve controller.(2) YES
Carry out the troubleshooting regarding the diesel fuel system.
(Refer to GROUP 13C.)
Follow inspection procedures for trouble symptom Nos. 3 or 4.
(Refer to P.17-21, 22.) NG
Replace the engine-ECU.
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ENGINE AND EMISSION CONTROL -Auto-cruise Control System17-23
Inspection Procedure 7
Hunting (repeated acceleration and deceleration) occurs
at the set vehicle speed.
Probable cause
The cause is probably a malfunction of vehicle speed sensor or GE actuator (electronic
governor).
In either case, a diagnosis code regarding the diesel fuel system must be confirmed.DMalfunction of the vehicle speed sensor
DMalfunction of the GE actuator (electronic governor)
DMalfunction of the engine-ECU
MUT-II Self-Diag code
Is a diagnosis code regarding the diesel fuel system output?YES
NO
Check trouble symptoms.NGReplace the engine-ECU.
Follow the troubleshooting regarding the diesel fuel system. (Refer
to GROUP 13C.)
Inspection Procedure 8
When the MAIN switch of the auto-cruise control switch is
turned on, the auto-cruise control indicator lamp does not
illuminate. (However, the auto-cruise control in normal.)
Probable cause
There may be a burnt-out bulb or a malfunction of the auto-cruise control indicator
lampcircuit.DBurnt-out bulb
DMalfunction of the harness
DMalfunction of the connector
DMalfunction of the engine-ECU
OK
Auto-cruise control indicatorlamp bulbcheckNG
Replace
NG
Repair
OK
NG
OK
Check trouble symptom.
NG
Check the harness between the J/B and the combination meter,
and repair if necessary.
Check the following connectors:
D-02, E-10, D-110
OK
Check trouble symptom.
NG
Repair
NG
Replace the engine-ECU.NG
Measure at the engine-ECU connector D-110.
DDisconnect the connector and measure at the harness side.
DIgnition switch and auto-cruise control MAIN switch: ON
DVoltage between terminal 22 and earth
OK:System voltage
Measure at the combination meter connector D-01.
DDisconnect the connector and measure at the harness side.
DIgnition switch and MAIN switch: ON
DVoltage between terminal 62 and earth
OK:System voltageCheck the following connector:D-01
NG
Check the harness between the combination meter and the engine-
ECU, and repair if necessary. OK
Check trouble symptom.
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ENGINE AND EMISSION CONTROL -Auto-cruise Control System17-24
Inspection Procedure 9
Auto-cruise control switch input system check
NG
Check the harness between the auto-cruise control switch and
the engine-ECU, and repair if necessary.
OK
NG
Repair
OK
Check trouble symptom. NG
OK
Auto-cruise control switch check (Refer to P.17-29.)NG
Replace
NG OKClock spring check (Refer to GROUP 52B.)
Repair
OK
NG
Repair
NG
OK
Check trouble symptom.
NG
Check the harness between the J/B and the auto-cruise control
switch, and repair if necessary.
Check the following connectors:
D-210, D-31, D-205, D-205-2, D-205-3
OK
Check trouble symptom.
NG
Repair
NG
Replace the engine-ECU.NG
Measure at the engine-ECU connector D-111.
DDisconnect the connector and measure at the harness side.
DIgnition switch and auto-cruise control MAIN switch: ON
DVoltage between terminal 45 and earth
OK:System voltage
Measure at the auto-cruise control switch connector D-205-3.
DDisconnect the connector and measure at the harness side.
DIgnition switch: ON
DVoltage between terminal 1 and earth
OK:System voltage
NG
Check the harness between the auto-cruise control switch and
the engine-ECU, and repair if necessary.
OK
Check trouble symptom.
Check the following connectors:
D-205-3, D-205-2, D-205, E-10, D-111
Measure at the engine-ECU connector D-112.
DDisconnect the connector and measure at the harness side.
DIgnition switch and auto-cruise control MAIN and CANCEL
switch: ON
DVoltage between terminal 61 and earth
OK:System voltageCheck the following connectors:
D-205-3, D-205-2, D-205, E-10, D-112
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ENGINE AND EMISSION CONTROL -Auto-cruise Control System17-25
DATA LIST REFERENCE TABLE
For the data, which is input to the engine-ECU
<6G7-M/T, 4M4>, engine-A/T-ECU <6G7-A/T> andthrottle valve controller <6G7>, the following items
can be read out by using the MUT-II
.
HOW TO READ OUT DATA LIST
1. Connect the MUT-II
to the 16-pin diagnosis
connector.
Caution
Turn off the ignition switch befor connecting
and disconnecting the MUT-II
.2. Turn the ignition switch to “ON” position.
3. Select “auto-cruise control” on the MUT-II
menu, and then read out the data list.
<6G7>
Terminal
No.Check itemCheck conditionsNormal condition
01Auto-cruiseMAINMAIN switch: ONON
control
switchMAIN switch: OFFOFF
02SETMAIN switch:SET switch: ONON
(COAST)ONSET switch: OFFOFF
03RESUMERESUME switch: ONON
(ACCEL)RESUME switch: OFFOFF
04CANCELCANCEL switch: ONON
CANCEL switch: OFFOFF
05Stop lamp switchBrake pedal: DepressedON
(for stop lamp circuit)Brake pedal: ReleasedOFF
06Stop lamp switchBrake pedal: DepressedOFF
(for auto-cruise control
circuit)
Brake pedal: ReleasedON
07Clutch switch
Brake pedal: ReleasedOFF
Inhibitor switchSelector lever: “N“, “P” positionON
Selector lever: Other than “N“, “P” positionOFF
08Accelerator switchAccelerator pedal: ReleasedON
(Idle position switch)Accelerator pedal: DepressedOFF
09Auto-cruise controlAuto-cruise control system: ActivatedON
systemAuto-cruise control system: Not activatedOFF
10Vehicle speed sensorRoad test the vehicleThe speedometer and
the MUT-IIdisplay the
same value.
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ENGINE AND EMISSION CONTROL -Auto-cruise Control System17-26
Terminal
No.Normal condition Check conditions Check item
11Throttle position sensorAccelerator pedal: Fully depressed450 - 800 mV
Accelerator pedal: DepressedThe more deeply the
pedal is depressed, the
higher value the MUT-
IIdisplay
Accelerator pedal: Release4,200 - 4,900 mV
12Accelerator pedalAccelerator pedal: Fully depressed985 - 1,085 mV
position sensorAccelerator pedal: DepressedThe more deeply the
pedal is depressed, the
higher value the MUT-
IIdisplay
Accelerator pedal: Release4,000 mV or more
<4M4>
Terminal
No.Check itemCheck conditionsNormal condition
01Auto-cruiseMAINMAIN switch: ONON
control
switchMAIN switch: OFFOFF
02SETMAIN switch:SET switch: ONON
(COAST)ONSET switch: OFFOFF
03RESUMERESUME switch: ONON
(ACCEL)RESUME switch: OFFOFF
04CANCELCANCEL switch: ONON
CANCEL switch: OFFOFF
05Stop lamp switchBrake pedal: DepressedON
(for stop lamp circuit)Brake pedal: ReleasedOFF
06Stop lamp switchBrake pedal: DepressedOFF
(for auto-cruise control
circuit)
Brake pedal: ReleasedON
07Clutch switch
Brake pedal: ReleasedOFF
Inhibitor switchSelector lever: “N”, “P” positionON
Selector lever: Other than “N”, “P” positionOFF
08Accelerator switchAccelerator pedal: ReleasedON
(Idle position switch)Accelerator pedal: DepressedOFF
09Auto-cruise controlAuto-cruise control system: ActivatedON
systemAuto-cruise control system: Not activatedOFF
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