Mitsubishi Evolution X. Manual - part 1065

ETACS

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CHASSIS ELECTRICAL

54A-621

DTC B210A: +B power supply (low input)

 

DTC B210B: +B power supply (high input)

CAUTION

Before replacing the ECU, ensure that the input 
and output signal circuits are normal.

.

TROUBLE JUDGMENT

The ETACS-ECU sets DTC B210A if the power sup-
ply fuse voltage decreases to the specified value or 
less, and sets DTC B210B if the power supply fuse 
voltage increases to the specified value or more. 
However, when the status returns to normal, the 
ETACS-ECU automatically erases DTCs B210A and 
B210B.

.

TECHNICAL DESCRIPTION (COMMENT)

The power supply fuse or the ETACS-ECU may have 
a problem.

.

TROUBLESHOOTING HINTS

• The power supply fuse may be defective.

• The ETACS-ECU may be defective.

• The battery may be defective.

• The generator may be defective.

• The wiring harness or connectors may have 

loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector

ETACS-ECU Power Supply Circuit

ETACS-ECU

FUSIBLE
LINK

36

RELAY
BOX

AC708972AX

Connector: C-307

ETACS-ECU

C-307 (B)

ETACS

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CHASSIS ELECTRICAL

54A-622

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB992006: Extra Fine Probe

• 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)

STEP 1. Power supply fuse check.
Q: Is the fuse in good condition?

YES : Go to Step 3.
NO :  Go to Step 2.

STEP 2. Wiring harness check between C-307 ETACS-ECU 
connector and fuse No. 30.
(1) Disconnect ETACS-ECU connector C-307.
(2) Remove fuse No. 30.
(3) Check the continuity (short to ground) between C-307 

ETACS-ECU connector terminal No. 2 and the ground.

OK: No continuity

Q: Is the check result normal?

YES : Replace the fuse No.30.
NO :  A short circuit may be present in the power supply 

circuit. Check the wiring harness between 
ETACS-ECU connector C-307 terminal No. 2 and 
fuse No. 30, and repair if necessary and replace fuse 
No. 30.

STEP 3. Battery check
Refer to 

P.54A-9

.

Q: Is the battery in good condition?

YES : Go to Step 4.
NO :  Charge or replace the battery.

STEP 4. Charging system check
Refer to GROUP 16 

− Output Current Test 

P.16-8

.

Q: Is the charging system in good condition?

YES : Go to Step 5.
NO :  Repair or replace the charging system component(s).

STEP 5. Check ETACS-ECU connector C-307 for loose, 
corroded or damaged terminals, or terminals pushed back 
in the connector.
Q: Is ETACS-ECU connector C-307 in good condition?

YES : Go to Step 6.
NO :  Repair or replace the component(s). Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

.

ETACS

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CHASSIS ELECTRICAL

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STEP 6. Check the battery power supply circuit to the 
ETACS-ECU. Measure the voltage at ETACS-ECU 
connector C-307.
(1) Disconnect ETACS-ECU connector C-307 and measure the 

voltage available at the wiring harness side of the 
connector.

(2) Measure the voltage between terminal 2 and ground.

• The voltage should measure approximately 12 volts 

(battery positive voltage).

Q: Is the measured voltage approximately 12 volts (battery 

positive voltage)?
YES : Go to Step 8.
NO :  Go to Step 7.

STEP 7. Check the wiring harness between ETACS-ECU 
connector C-307 (terminal 2) and the fusible link (36).
Check the power supply line for open circuit.
Q: Is the wiring harness between ETACS-ECU connector 

C-307 (terminal 2) and the fusible link (36) in good 
condition?
YES : No action is necessary and testing is complete.
NO :  The wiring harness may be damaged or the 

connector(s) may have loose, corroded or damaged 
terminals, or terminals pushed back in the connector. 
Repair the wiring harness as necessary.

AC608254 BF

Harness side: C-307

ETACS

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STEP 8. Using scan tool MB991958, check data list.
Check the power supply fuse voltage.

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.54A-579

."

(2) Check the ETACS data list.

• Turn the ignition switch to the "LOCK" (OFF) position.

Q: Do the scan tool MB991958 display the item "voltage 

sensing of IOD Line" is normal condition?
YES : Go to Step 9.
NO :  Replace the ETACS-ECU.

STEP 9. Recheck for diagnostic trouble code.
Check again if the DTC is set to the ETACS-ECU.
(1) Erase the DTC.
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" 

position.

(3) Check if DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES : Replace the ETACS-ECU.
NO :  The trouble can be an intermittent malfunction (Refer 

to GROUP 00, How to Cope with Intermittent 
Malfunction 

P.00-15

).

Item No.

Item name

Normal 
condition

Item 253

Voltage sensing 
of IOD Line

Approximately 
12 volts (battery 
positive voltage)

AC608435

Data link connector

MB991827

MB991824

MB991910

AB