Mitsubishi Grandis. Manual - part 791

AUTO-CRUISE CONTROL

ENGINE AND EMISSION CONTROL

17-5

SPECIAL TOOL

M1172000600361

TROUBLESHOOTING

DIAGNOSIS TROUBLESHOOTING FLOW

M1172002000332

Refer to GROUP 00 - How to Use 
Troubleshooting/Inspection Service Points 

P.00-5

.

DIAGNOSIS FUNCTION

M1172002100340

METHOD OF READING THE DIAGNOSIS 
CODE

Use the MUT-III to read the diagnosis code (Refer to 
GROUP 00 

− How to Use 

Troubleshooting/Inspection Service Points 

P.00-5

).

Tool

Number

Name

Use

MB991955

A: MB991824
B: MB991827
C: MB991910
D: MB991911
E: MB991825
F: MB991826

MUT-III 
sub-assembly

A: Vehicle 

Communicati
on Interface 
(V. C. I.)

B: MUT-III USB 

cable

C: MUT-III main 

harness A 
(Vehicles with 
CAN 
communicatio
n system)

D: MUT-III main 

harness B 
(Vehicles 
without CAN 
communicatio
n system)

E: MUT-III 

measurement 
adapter

F: MUT-III 

trigger 
harness

Reading diagnosis code

CAUTION

MUT-III main harness A should 
be used. MUT-III main harness B 
should not be used for this 
vehicle. If you connect MUT-III 
main harness B instead, the CAN 
communication does not 
function correctly.

MB991658

Test harness

Inspection of data list

MB991910

MB991826

MB991955

MB991911

MB991824

MB991827

MB991825

A

B

C

D

E

F

DO NOT USED

MB991658

AUTO-CRUISE CONTROL

ENGINE AND EMISSION CONTROL

17-6

METHOD OF ERASING THE DIAGNOSIS 
CODE

Use the MUT-III to erase the diagnosis code (Refer 
to GROUP 00 

− How to Use 

Troubleshooting/Inspection Service Points 

P.00-5

).

CHECK CHART FOR DIAGNOSIS CODES

M1172002200358

Code No.

Diagnosis item

Reference page

15

Auto-cruise control switch system

P.17-7

21

Cancel latch signal system

P.17-20

22

Stop lamp switch system <L.H. drive vehicles>

P.17-21

Stop lamp switch system <R.H. drive vehicles>

P.17-30

23

Engine-ECU <M/T> or engine-A/T-ECU <A/T> and 
its related components

P.17-38

AUTO-CRUISE CONTROL

ENGINE AND EMISSION CONTROL

17-7

DIAGNOSTIC TROUBLE CODE 
PROCEDURES

Code No.15 Auto-cruise Control Switch System

OPERATION

This circuit judges the signals of each switch (SET, 
RESUME and CANCEL) of the auto-cruise control 
switch. The engine-ECU <M/T> or engine-A/T-ECU 
<A/T> detects the state of the auto-cruise control 
switch by sensing the voltages shown below.

• When all switches are OFF: 4.7 − 5.0 volts

• When the MAIN switch is ON: 0 − 0.3 volt 

• When the SET switch is ON: 2.0 − 2.8 volts 

• When the RESUME switch is ON: 3.3 − 4.1 volts 

• When the CANCEL switch is ON: 0.8 − 1.5 volts 

DIAGNOSIS CODE SET CONDITIONS

If the auto-cruise control switch is operated, this 
diagnosis code will be set when the engine-ECU 
<M/T> or engine-A/T-ECU <A/T> terminal voltage is 
different from the standard value.

AC311228

Auto-cruise
control switch

Clock
spring

Auto-cruise control switch system circuit

Engine-ECU <M/T> or engine-A/T-ECU <A/T>

C-114

C-113

C-17

C-310

C-311

C-304

C-305

Wire colour code
B: Black  LG: Light green  G: Green  L: Blue  W: White  Y: Yellow  SB: Sky blue  BR: Brown  O: Orange  GR: Gray
R: Red  P: Pink  V: Violet

G

B

B

B-W

V-W

V-W

V-R

V-R

AUTO-CRUISE CONTROL

ENGINE AND EMISSION CONTROL

17-8

POSSIBLE CAUSES

• Malfunction of the auto-cruise control switch.

• Malfunction of the clock spring.

• Damaged harness or connector.

• Malfunction of the engine-ECU <M/T>.

• Malfunction of the engine-A/T-ECU <A/T>.

DIAGNOSIS

STEP 1. MUT-III data list

• Item 01: Main switch (Refer to data list reference 

table 

P.17-50

).

• Item 02: Set switch (Refer to data list reference 

table 

P.17-50

).

• Item 03: Resume switch (Refer to data list 

reference table 

P.17-50

).

• Item 04: Cancel switch (Refer to data list 

reference table 

P.17-50

).

Q: Is the check result normal?

YES : 

Go to Step 17.

NO : 

Go to Step 2.

STEP 2. Measure the voltage at auto-cruise 
control switch connector C-305.
(1) Remove the air bag module (driver’s side) (Refer 

to GROUP 52B,  Driver’s, Front Passenger’s Air 

Bag Module(s) and Clock Spring 

P.52B-225

).

(2) Connect the negative (

−) battery cable.

(3) Turn the ignition switch to the "ON" position and 

the MAIN switch to the "OFF" position.

(4) Measure the voltage between connector C-305 

terminal No.2 and earth.

OK: 4.7

−5.0 V

(5) Turn the ignition switch to the "LOCK" (OFF) 

position.

Q: Is the check result normal?

YES : 

Go to Step 9.

NO : 

Go to Step 3.

AC311366

Connector: C-305

<L.H. drive vehicles>

<R.H. drive vehicles>

C-305 (Y)

C-305 (Y)

AC

Clock
spring

Clock
spring

1 2 3

AC205053AI

C-305 harness 
connector: 
harness side