ECU MITSUBISHI 380 2005 Workshop Manual

AUTO-CRUISE CONTROL
ENGINE AND EMISSION CONTROL17-50
DTC 1574: Engine ECU and Its Related Components
.
DTC SET CONDITIONS
This DTC is set when there is a failure in the Engine
ECU and its related components.
.
TROUBLESHOOTING HINTS (THE MOST
LIKELY CAUSES FOR THIS CODE TO BE
SET ARE:)
Malfunction of the MPI system.
Malfunction of the A/T system.
Malfunction of the Engine ECU.
Circuit drawings
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
Refer to component locations GROUP-70
DIAGNOSIS
Required Special Tools:
MB991958: Diagnostic Tool (MUT-III Sub Assembly)
MB991824: V.C.I.
MB991827: MUT-III USB Cable
MB991910: MUT-III Main Harness A
STEP 1. Using Diagnostic Tool MB991958, read the MPI
system diagnostic trouble code.
To prevent damage to Diagnostic Tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting Diagnostic Tool
MB991958.
(1) Connect Diagnostic Tool MB991958 to the data link
connector. (Refer to P.17-11).
(2) Turn the ignition switch to the "ON" position.
(3) Check for MPI system diagnostic trouble code. (Refer to
GROUP 13A, MPI Diagnosis
Diagnostic Function How
to Read and Erase Diagnostic Trouble Code 13A-6) .
(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Disconnect Diagnostic Tool MB991958.
Q: Is any DTC set?
YES : Diagnose the MPI system. (Refer to GROUP 13A,
MPI Diagnosis
Diagnostic Trouble Code Chart
13A-17) . Then go to Step 4.
NO : Go to Step 2.

AUTO-CRUISE CONTROL
ENGINE AND EMISSION CONTROL17-51
STEP 2. Using Diagnostic Tool MB991958, read the A/T
system diagnostic trouble code.
To prevent damage to Diagnostic Tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting Diagnostic Tool
MB991958.
(1) Connect Diagnostic Tool MB991958 to the data link
connector. (Refer to P.17-11).
(2) Turn the ignition switch to the "ON" position.
(3) Check for A/T system diagnostic trouble code. (Refer to
GROUP 23A, A/T Diagnosis
Diagnostic Function How
to Read and Erase Diagnostic Trouble Code P.23A-13).
(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Disconnect Diagnostic Tool MB991958.
Q: Is any DTC set?
YES : Diagnose the A/T system. (Refer to GROUP 23A, A/T
Diagnosis
Diagnostic Trouble Code Chart
P.23A-34). Then go to Step 4.
NO : Go to Step 3.
STEP 3. Using Diagnostic Tool MB991958, read the
auto-cruise control system diagnostic trouble code.
To prevent damage to Diagnostic Tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting Diagnostic Tool
MB991958.
(1) Connect Diagnostic Tool MB991958 to the data link
connector. (Refer to P.17-11).
(2) Turn the ignition switch to the "ON" position.
(3) Use Diagnostic Tool MB991958 to read the auto-cruise
control system diagnostic trouble codes. (Refer to P.17-11).
(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Disconnect Diagnostic Tool MB991958.
Q: Is DTC 1574 set?
YES : Replace the Engine ECU.[Refer to GROUP 13A,
Engine ECU 13A-675] . Then go to Step 4.
NO : It can be assumed that this malfunction is intermittent.
(Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
How to
Cope with Intermittent Malfunction P.00-14).

AUTO-CRUISE CONTROL
ENGINE AND EMISSION CONTROL17-53
SYMPTOM CHARTM1172002300366
NOTE: If engine speed reaches and exceeds 6000
r/min the Auto Cruise Control System will be can-
celled automatically.SYMPTOM INSPECTION
PROCEDURE NO.REFERENCE
PA G E
Communication with
Diagnostic Tool is
not possibleCommunication with all systems is
impossible- Group 13A, MPI
Diagnosis

Symptom
Procedures

Inspection
Procedure 1
13A-539 .
Communication with the Engine ECU only
is impossible- Group 13A, MPI
Diagnosis

Symptom
Procedures

Inspection
Procedure 2
13A-541 .
Auto-cruise control
system is not
cancelled.When brake pedal is depressed 1
P.17-54
When selector lever is moved to "N" range 2
P.17-54
When "CANCEL" switch is turned ON 3
P.17-55
When clutch pedal is depressed 4
P.17-55
Auto-cruise control system cannot be set. 5
P.17-56
Hunting (repeated acceleration and deceleration) occurs at the
set vehicle speed.6
P.17-60
When "CRUISE" (MAIN) switch is turned "ON", "CRUISE"
indicator lamp inside combination meter does not illuminate.
(However, auto-cruise control system is normal).7
P.17-62

AUTO-CRUISE CONTROL
ENGINE AND EMISSION CONTROL17-54
SYMPTOM PROCEDURES
INSPECTION PROCEDURE 1: When the Brake Pedal is Depressed, Auto-cruise Control System is not
Cancelled.
.
COMMENT
The stoplamp switch circuit is suspected.
.
TROUBLESHOOTING HINTS (THE MOST
LIKELY CAUSES FOR THIS CASE:)
Malfunction of the stoplamp switch.
Damaged harness or connector.
Malfunction of the Engine ECU.
Circuit drawings
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
Refer to component locations GROUP-70
DIAGNOSIS
Refer to P.17-35, Diagnostic Trouble Code Procedures DTC
22: Stoplamp Switch System.
INSPECTION PROCEDURE 2: When the Selector Lever is Moved to "N" Range, Auto-cruise Control
System is not Cancelled.
.
COMMENT
The transmission inhibitor switch circuit is suspected.
.
TROUBLESHOOTING HINTS (THE MOST
LIKELY CAUSES FOR THIS CASE:)
Malfunction of the transmission inhibitor switch.
Damaged harness or connector.
Malfunction of the Engine ECU.
Malfunction of A/T ECU.
Circuit drawings
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
Refer to component locations GROUP-70
DIAGNOSIS
Refer to GROUP 23A, A/T Diagnosis Diagnostic Trouble
Code Procedures
DTC 0705: Transmission Inhibitor Switch
System (Open/short Circuit) P.23A-97.

AUTO-CRUISE CONTROL
ENGINE AND EMISSION CONTROL17-55
INSPECTION PROCEDURE 3: When the Auto-cruise Control "CANCEL" Switch is Set to ON,
Auto-cruise Control System is not Cancelled.
.
COMMENT
The cause is probably an open-circuit in the output in
the circuit inside the "CANCEL" switch.
.
TROUBLESHOOTING HINTS (THE MOST
LIKELY CAUSES FOR THIS CASE:)
Malfunction of the auto-cruise control switch.
Circuit drawings
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
Refer to component locations GROUP-70
DIAGNOSIS
Replace the auto-cruise control switch. (Refer to P.17-75,
Auto-cruise Control).
INSPECTION PROCEDURE 4: When the Clutch Pedal is Depressed, Auto-cruise Control System is not
Cancelled.
.
COMMENT
The clutch switch circuit is suspected.
.
TROUBLESHOOTING HINTS (THE MOST
LIKELY CAUSES FOR THIS CASE:)
Malfunction of the clutch switch.
Damaged harness or connector.
Malfunction of the Engine ECU.
Circuit drawings
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
Refer to component locations GROUP-70
DIAGNOSIS
Refer to P.17-15, Diagnostic Trouble Code Procedures DTC
0830: Clutch Switch System.

AUTO-CRUISE CONTROL
ENGINE AND EMISSION CONTROL17-56
INSPECTION PROCEDURE 5: Auto-cruise Control System cannot be Set.
.
COMMENT
The fail-safe function is probably canceling
auto-cruise control system. In this case, Diagnostic
Tool MB991958 can be used to retest each system
by checking the diagnostic trouble codes. The
Diagnostic Tool can also be used to check if the cir-
cuits of each input switch are normal or not by check-
ing the input switch codes.
.
TROUBLESHOOTING HINTS (THE MOST
LIKELY CAUSES FOR THIS CASE:)
Malfunction of the auto-cruise control switch.
Malfunction of the stoplamp switch.
Malfunction of the transmission inhibitor switch.
Malfunction of the Engine ECU.
Circuit drawings
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
Refer to component locations GROUP-70
DIAGNOSIS
Required Special Tools:
MB991958: Diagnostic Tool (MUT-III Sub Assembly)
MB991824: V.C.I.
MB991827: MUT-III USB Cable
MB991910: MUT-III Main Harness A
STEP 1. Using Diagnostic Tool MB991958, read the
diagnostic trouble code.
To prevent damage to Diagnostic Tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting Diagnostic Tool
MB991958.
(1) Connect Diagnostic Tool MB991958 to the data link
connector. (Refer to P.17-11).
(2) Turn the ignition switch to the "ON" position.
(3) Check for auto-cruise control system diagnostic trouble
code. (Refer to P.17-11).
(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Disconnect Diagnostic Tool MB991958.
Q: Is DTC set?
YES : Diagnose the auto-cruise control system. (Refer to
P.17-14, Diagnostic Trouble Code Chart). Then go to
St e p 6 .
NO : Go to Step 2.

AUTO-CRUISE CONTROL
ENGINE AND EMISSION CONTROL17-59
STEP 4. Using Diagnostic Tool MB991958, check A/T data
list item 34: Transmission Inhibitor Switch.
To prevent damage to Diagnostic Tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting Diagnostic Tool
MB991958.
(1) Connect Diagnostic Tool MB991958 to the data link
connector. (Refer to P.17-11).
(2) Turn the ignition switch to the "ON" position.
(3) Set Diagnostic Tool MB991958 to data reading mode for
Auto Transmission system. (Refer to P.17-11).
Item 34, Transmission Inhibitor Switch.
When selector lever is at the "P" or "N" position, the
display on Diagnostic Tool MB991958 should be
"ON".
When selector lever is at the "R" or "D" position, the
display on Diagnostic Tool MB991958 should be
"OFF".
(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Disconnect Diagnostic Tool MB991958.
Q: Is the switch operating properly?
YES : Go to Step 5.
NO : Refer to P.17-54, Symptom Procedures
Inspection
Procedure 2. Then go to Step 6.
STEP 5. Check the symptoms.
Q: Can auto-cruise control be set?
YES : It can be assumed that this malfunction is intermittent.
(Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
How to
Cope with Intermittent Malfunction P.00-14).
NO : Replace the Engine ECU.[Refer to GROUP 13A,
Engine ECU 13A-675] . Then go to Step 6.
STEP 6. Check the symptoms.
Q: Can auto-cruise control be set?
YES : The procedure is complete.
NO : Return to Step 1.

AUTO-CRUISE CONTROL
ENGINE AND EMISSION CONTROL17-60
INSPECTION PROCEDURE 6: Hunting (Repeated Acceleration and Deceleration) Occurs at the Set
Vehicle Speed.
.
COMMENT
The output shaft speed sensor signal or the throttle
body is suspected.
.
TROUBLESHOOTING HINTS (THE MOST
LIKELY CAUSES FOR THIS CASE:)
Malfunction of the output shaft speed sensor.
Malfunction of the throttle body.
Malfunction of the Engine ECU.
Malfunction of the A/T ECU.
Circuit drawings
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
Refer to component locations GROUP-70
DIAGNOSIS
Required Special Tools:
MB991958: Diagnostic Tool (MUT-III Sub Assembly)
MB991824: V.C.I.
MB991827: MUT-III USB Cable
MB991910: MUT-III Main Harness A
STEP 1. Using Diagnostic Tool MB991958, read the
diagnostic trouble code.
To prevent damage to Diagnostic Tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting Diagnostic Tool
MB991958.
(1) Connect Diagnostic Tool MB991958 to the data link
connector. (Refer to P.17-11).
(2) Turn the ignition switch to the "ON" position.
(3) Check for A/T system diagnostic trouble code. (Refer to
GROUP 23A, A/T Diagnosis
Diagnostic Function How
to Read and Erase Diagnostic Trouble Code P.23A-13).
(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Disconnect Diagnostic Tool MB991958.
Q: Is any DTC set?
YES : Diagnose the A/T system. (Refer to GROUP 23A, A/T
Diagnosis
Diagnostic Trouble Code Chart
P.23A-34). Then go to Step 4.
NO : Go to Step 2.

AUTO-CRUISE CONTROL
ENGINE AND EMISSION CONTROL17-61
STEP 2. Using Diagnostic Tool MB991958, read the
diagnostic trouble code.
To prevent damage to Diagnostic Tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting Diagnostic Tool
MB991958.
(1) Connect Diagnostic Tool MB991958 to the data link
connector. (Refer to P.17-11).
(2) Turn the ignition switch to the "ON" position.
(3) Check for MPI system diagnostic trouble code(Refer to
GROUP 13A, MPI Diagnosis
Diagnostic Function How
to Read and Erase Diagnostic Trouble Code 13A-6).
(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Disconnect Diagnostic Tool MB991958.
Q: Is any DTC set?
YES : Diagnose the MPI system. (Refer to GROUP 13A,
MPI Diagnosis
Diagnostic Trouble Code Chart
13A-17). Then go to Step 4.
NO : Go to Step 3.
STEP 3. Retest the system
Q: Does hunting occur?
YES : Replace the Engine ECU[Refer to GROUP 13A,
Engine ECU 13A-675]. Then go to Step 4.
NO : It can be assumed that this malfunction is intermittent.
(Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
How to
Cope with Intermittent Malfunction P.00-14).
STEP 4. Retest the system
Q: Does hunting occur?
YES : Return to Step 1.
NO : The procedure is complete.

AUTO-CRUISE CONTROL
ENGINE AND EMISSION CONTROL17-63
CIRCUIT OPERATION
The Engine ECU detects "CRUISE" (MAIN) switch
"ON" signal to illuminate the "CRUISE" indicator
lamp on the combination meter.
.
COMMENT
Connector(s), wiring harness in the CAN bus line
between the Engine ECU and the combination
meter, power supply to the Engine ECU, the combi-
nation meter, the Engine ECU may be defective.
.
TROUBLESHOOTING HINTS
Malfunction of the combination meter.
Damaged harness or connector.
Malfunction of the Engine ECU.
Circuit drawings
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
Refer to component locations GROUP-70
DIAGNOSIS
Required Special Tools:
MB991958: Diagnostic Tool (MUT-III Sub Assembly)
MB991824: V.C.I.
MB991827: MUT-III USB Cable
MB991910: MUT-III Main Harness A
STEP 1. Using Diagnostic Tool MB991958, diagnose the
CAN bus line.
To prevent damage to Diagnostic Tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting Diagnostic Tool
MB991958.
(1) Connect Diagnostic Tool MB991958 to the data link
connector. (Refer to P.17-11).
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line. (Refer to P.17-11).
(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Disconnect Diagnostic Tool MB991958.
Q: Is the check result satisfactory?
YES : Go to Step 2
NO : Repair the CAN bus lines. (Refer to GROUP 54C,
Diagnosis
Can Bus Diagnostic Chart P.54C-15).
Then go to Step 4.