Mitsubishi Outlander GS45X. Manual - part 997

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-15

STEP 6. Measure the resistance at A/C control panel 
connector C-119.
(1) Disconnect A/C control panel connector C-119, and 

measure the resistance at the wiring harness side.

(2) Measure the resistance value between terminal 7 and 

ground.

• The measured value should be 2 ohms or less.

Q: Does the measured resistance value correspond with 

this range?
YES :  Go to Step 8.
NO :   Go to Step 7.

STEP 7. Check the wiring harness between A/C control 
panel connector C-119 (terminal 7) and ground.

• Check the A/C control panel ground line for open circuit.

Q: Is the wiring harness between A/C control panel 

connector C-119 (terminal 7) and ground in good 
condition?
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 Malfunctions 

P.00-15

.

NO :  Repair the wiring harness.

STEP 8. Check A/C-ECU connector C-109 for loose, 
corroded or damaged terminals, or terminals pushed back 
in the connector.
Q: Is A/C-ECU connector C-109 in good condition?

YES : Go to Step 9.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

.

STEP 9. Check the wiring harness between A/C-ECU 
connector C-109 (terminal 9) and A/C control panel 
connector C-119 (terminal 9).

• Check the A/C control panel signal line for open and short 

circuit.

Q: Is the wiring harness between A/C-ECU connector 

C-109 (terminal 9) and A/C control panel connector 
C-119 (terminal 9) in good condition?
YES : Go to Step 10.
NO :  Repair the wiring harness.

AC608812EE

Harness side: C-119

MANUAL A/C DIAGNOSIS

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HEATER, AIR CONDITIONING AND VENTILATION

55A-16

STEP 10. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the check result satisfactory?

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 Malfunctions 

P.00-15

.

NO :  Replace the A/C control panel. Then go to Step 11.

STEP 11. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the check result satisfactory?

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 Malfunctions 

P.00-15

.

NO :  Replace the A/C-ECU.

DTC B1003: Mode Dial SW Error

AC901231

A/C-ECU

CPU

A/C Control Panel Circuit

INTERFACE 
CIRCUIT

A/C 
CONTROL 
PANEL

MANUAL A/C DIAGNOSIS

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HEATER, AIR CONDITIONING AND VENTILATION

55A-17

.

DTC SET CONDITION

DTC B1003 will be set when the A/C-ECU cannot 
receive the signal of mode selection knob.

.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble

• The A/C-ECU, the A/C control panel, or connec-

tor(s) or wiring between the two may be defec-
tive.

Past trouble

• If DTC B1003 is stored as a past trouble, carry 

out diagnosis with particular emphasis on wiring 
and connector(s) between the A/C-ECU and the 
A/C control panel. If the connectors and wiring 
are normal, and obviously the ECU is the cause 
of the trouble, replace the ECU. If in doubt, do not 
replace the ECU.

.

TROUBLESHOOTING HINT

• Malfunction of connector.

• Malfunction of the harness.

• Malfunction of the A/C control panel.

• Malfunction of the A/C-ECU.

DIAGNOSIS

Required Special Tool:

•  MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A (Vehicles with 

CAN communication system)

AC702208

Connector: C-109, C-119

C-119

C-109 (B) 

AE

MANUAL A/C DIAGNOSIS

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STEP 1. Using scan tool MB991958, diagnose the CAN bus 
line

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the 

Scan Tool (M.U.T.-III) 

P.55A-7

."

(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.
NO :  Repair the CAN bus line. (Refer to GROUP 54C, 

Diagnosis 

P.54C-17

).

STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Q: Is the check result satisfactory?

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 Malfunctions 

P.00-15

.

NO :  Go to Step 3. 

STEP 3. Check A/C control panel connector C-119 and 
A/C-ECU connector C-109 for loose, corroded or damaged 
terminals, or terminals pushed back in the connector.
Q: Are A/C control panel connector C-119 and A/C-ECU 

connector C-109 in good condition?
YES : Go to Step 4.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

.

ZC501967

AC404789

AC701411AB

MB991824

MB991827

MB991910

Data link 
connector