Mitsubishi Evolution X. Manual - part 1274

 

  Index      Mitsubishi     Mitsubishi Evolution X - service repair manual 2008 year

 

Search            

 

 

 

 

 

 

 

 

 

Content   ..  1272  1273  1274  1275   ..

 

 

Mitsubishi Evolution X. Manual - part 1274

 

 

AUTO A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55-47

STEP 2. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Connect scan tool MB991958 to the data link connector
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES : Replace the A/C-ECU. On completion, check that the 

DTC is not reset.

NO :  There is an intermittent malfunction such as poor 

engaged connector(s) or open circuit (Refer to 
GROUP 00, How to Use Troubleshooting/Inspection 
Service Points 

− How to Cope with Intermittent 

Malfunctions 

P.00-15

.)

DTC U0141: ETACS-ECU Time-out

CAUTION

If DTC U0141 is set in the A/C-ECU, diagnose the 
CAN main bus line.

CAUTION

Whenever the ECU is replaced, ensure that the 
communication circuit is normal.

.

TROUBLE JUDGMENT

The A/C-ECU receives air conditioning opera-
tion-related signals from the ETACS-ECU via the 
CAN bus lines. If the ECU cannot receive any of the 
air conditioning control-related signals from the 
ETACS-ECU, the diagnostic trouble code U0141 is 
stored.

.

TECHNICAL DESCRIPTION (COMMENT) 

Current trouble

• Connector(s) or wiring harness in the CAN bus 

lines between the ETACS-ECU and the 
A/C-ECU, the power supply system to the 
ETACS-ECU, the ETACS-ECU itself, or the 
A/C-ECU may be defective.

Past trouble

• If DTC U0141 is stored as a past trouble, carry 

out diagnosis with particular emphasis on wiring 
and connector(s) in the CAN bus line between 
the A/C-ECU and the ETACS-ECU, and the 
power supply system to the ETACS-ECU. 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.
NOTE: For a past trouble, you cannot find it by 
the scan tool CAN bus diagnostics even if there is 
a failure in CAN bus lines. In this case, refer to 
GROUP 00, How to Use Troubleshooting/Inspec-
tion Service Points 

 How to Cope with Intermit-

tent Malfunctions 

P.00-15

) and check the CAN 

bus lines. You can narrow down the possible 
cause of the trouble by referring to the DTC, 
which is set regarding the CAN communica-
tion-linked ECUs (Refer to GROUP 54C, Expla-
nation about the scan too CAN bus diagnostics 

P.54C-14

).

.

TROUBLESHOOTING HINTS

• Malfunction of the A/C-ECU

• Malfunction of the ETACS-ECU

• Damaged harness wires and connectors

AUTO A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55-48

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB992006: Extra Fine Probe

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

• MB991824: V.C.I.

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A

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.55-7

."

(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-14

).

STEP 2. Using scan tool MB991958 read the ETACS-ECU 
diagnostic trouble code.
Check whether an ETACS-ECU DTCs are set or not.
(1) Turn the ignition switch to the "ON" position.
(2) Check for ETACS-ECU DTCs.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES :  Diagnose the ETACS-ECU (Refer to GROUP 54A, 

Diagnostic Trouble Code 

P.54A-582

).

NO :   Go to Step 3.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

AUTO A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55-49

STEP 3. Using scan tool MB991958, check for any 
diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked 
systems below, is set.

• Combination meter

DTC indicating a time-out error related to the engine or 
automatic transaxle control system

(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES : Go to Step 4.
NO :  Go to Step 5.

STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES :  Replace the ETACS-ECU. On completion, check that 

the DTC is not reset.

NO :  There is an intermittent malfunction such as poor 

engaged connector(s) or open circuit (Refer to 
GROUP 00, How to Use Troubleshooting/Inspection 
Service Points 

− How to Cope with Intermittent 

Malfunctions 

P.00-15

.)

STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES : Replace the A/C-ECU. On completion, check that the 

DTC is not reset.

NO :  There is an intermittent malfunction such as poor 

engaged connector(s) or open circuit (Refer to 
GROUP 00, How to Use Troubleshooting/Inspection 
Service Points 

− How to Cope with Intermittent 

Malfunctions 

P.00-15

.)

AUTO A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55-50

DTC U0151: SRS-ECU Time-out

CAUTION

If DTC U0151 is set in the A/C-ECU, diagnose the 
CAN main bus line.

CAUTION

Whenever the ECU is replaced, ensure that the 
communication circuit is normal.

.

TROUBLE JUDGMENT

The A/C-ECU receives air conditioning opera-
tion-related signals from the SRS-ECU via the CAN 
bus lines. If any of the air conditioning control-related 
signals from the SRS-ECU cannot be received, the 
diagnostic trouble code U0151 is stored.

.

TECHNICAL DESCRIPTION (COMMENT) 

Current trouble

• Connector(s) or wiring harness in the CAN bus 

lines between the SRS-ECU and the A/C-ECU, 
the power supply system to the SRS-ECU, the 
SRS-ECU itself, or the A/C-ECU may be defec-
tive.

Past trouble

• If DTC U0151 is stored as a past trouble, carry 

out diagnosis with particular emphasis on wiring 
and connector(s) in the CAN bus line between 
the A/C-ECU and the SRS-ECU, and the power 
supply system to the SRS-ECU. 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.
NOTE: For a past trouble, you cannot find it by 
the scan tool CAN bus diagnostics even if there is 
a failure in CAN bus lines. In this case, refer to 
GROUP 00, How to Use Troubleshooting/Inspec-
tion Service Points 

 How to Cope with Intermit-

tent Malfunctions 

P.00-15

) and check the CAN 

bus lines. You can narrow down the possible 
cause of the trouble by referring to the DTC, 
which is set regarding the CAN communica-
tion-linked ECUs (Refer to GROUP 54C, Expla-
nation about the scan too CAN bus diagnostics 

P.54C-14

).

.

TROUBLESHOOTING HINTS

• Malfunction of the SRS-ECU

• Malfunction of the A/C-ECU

• Damaged harness wires and connectors

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB992006: Extra Fine Probe

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

• MB991824: V.C.I.

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A

 

 

 

 

 

 

 

Content   ..  1272  1273  1274  1275   ..