Mitsubishi 380. Manual - part 871

IGNITION SWITCH

CHASSIS ELECTRICAL

54A-18

DTC12: Encrypted Codes are Not the Same or Not Registered.

.

DTC SET CONDITION

The encrypted code sent by the transponder is not 
the same encrypted code which is registered in the 
ETACS-ECU.

NOTE: DTC 12 is always output together with MPI 
system DTC P0513.

.

TROUBLESHOOTING HINTS

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

• The encrypted code in the ignition key has not 

been properly registered 

• Malfunction of ETACS-ECU

.

DIAGNOSIS

Was the encrypted code registered?

YES : Replace the ETACS-ECU and then re-register the 

encrypted code (Refer to 

P.54A-37

).

NO :  Register the encrypted code (Refer to 

P.54A-37

).

SYMPTOM CHART

M1543007201105

CAUTION

During diagnosis, a DTC code associated with 
other system may be set when the ignition switch 
is turned on with connector(s) disconnected. On 
completion, confirm all systems for DTC code(s). 
If DTC code(s) are set, erase them all.

SYMPTOM

INSPECTION 
PROCEDURE NO.

REFERENCE PAGE

Communication with diagnostic tool MB991958 is impossible.

1

P.54A-19

The ignition key cannot be registered.

2

P.54A-30

Engine cranks, but does not start.

3

P.54A-31

IGNITION SWITCH

CHASSIS ELECTRICAL

54A-19

SYMPTOM PROCEDURES

INSPECTION PROCEDURE 1: Communication with Diagnostic Tool MB991958 is Impossible.

.

CIRCUIT OPERATION

The ETACS-ECU is energized by the MPI relay when 
the ignition switch is turned "ON". The Engine-ECU 
transmits a signal from diagnostic tool MB991958 to 
the ETACS-ECU as it is. In the same way, a signal 
from the ETACS-ECU is also transmitted to 
diagnostic tool MB991958 as it is.

.

TECHNICAL DESCRIPTION (COMMENT)

• This malfunction may be caused by a defective 

ETACS-ECU, Engine-ECU, or a defect in the 
communication line between the ETACS-ECU 
and Engine-ECU. If this malfunction appears 
when the MPI system and diagnostic tool 
MB991958 can communicate each other, MPI 
system DTC P0513 will reset.

• If the MPI system is normal, the MPI relay can be 

determined as normal. In addition, if the MPI sys-
tem and diagnostic tool MB991958 can communi-
cate each other, the circuits between the data link 
connector and the Engine-ECU can determined 
as normal.

16DB407A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

A/T

CONTROL

UNIT

AC305210

CONNECTOR: A-13

AS

A-13 (GR)

AC305977

CONNECTOR: B-17X

AM

54DB006A

CONNECTORS: C-218

JUNCTION BLOCK
(REAR VIEW)

C-218 (GR)

HARNESS SIDE

45

46

48 47

49

50
59

51
60

52

53
62

65

61

54
63

56

68

64

67 66

57

58

55

IGNITION SWITCH

CHASSIS ELECTRICAL

54A-20

NOTE: If this malfunction appears, MPI system 
DTC P0513 will be output.

.

TROUBLESHOOTING HINTS

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

• Malfunction of the ETACS-ECU

• Malfunction of the Engine-ECU

• The wiring harness or connectors may have 

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

.

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB991958: Diagnostic Tool (MUT-III Sub Assembly)

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

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A (Vehicles with CAN 

communication system)

STEP 1. Using diagnostic tool MB991958, read the MPI 
system diagnostic trouble code.

CAUTION

To prevent damage to diagnostic tool MB991958, always 
turn the ignition switch to "LOCK" (OFF) position before 
connecting or disconnecting diagnostic tool.
 Use diagnostic tool MB991958 to confirm the MPI system 
DTC.
(1) Connect diagnostic tool MB991958 to the data link 

connector.

(2) Turn the ignition switch "ON" to position.
(3) Read the MPI system diagnosis code.

NOTE: If the diagnostic tool MB991958 cannot communi-
cate with the MPI system, refer to GROUP 13A, MPI Diag-
nosis 

− Symptom Procedures Chart 

P.13A-21

.

Q: Is an MPI system DTC P0513 output?

YES : Refer to GROUP 13A, MPI Diagnosis 

− Diagnostic 

Trouble Code Chart 

P.13A-17

.

NO :  Go to Step 2.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

IGNITION SWITCH

CHASSIS ELECTRICAL

54A-21

STEP 2. Check ETACS-ECU connector C-219 for loose, 
corroded or damaged terminals, or terminals pushed back 
in the connector.
Q: Is ETACS-ECU connector C-219 in good condition?

YES : Go to Step 3.
NO :  Repair or replace the damaged component(s). Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

. If the functions or equipment described in 

"CIRCUIT OPERATION" work normally, the interior 
light loaded signal should be normal.

STEP 3. Check the battery line of power supply circuit to 
the ETACS-ECU. Measure the voltage at ETACS-ECU 
connector C-219.
(1) Disconnect ETACS-ECU connector C-219 and measure the 

voltage available at the junction block side of the connector.

(2) Measure the voltage between terminal 20 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 5.
NO :  Go to Step 4.

54DB014A

CONNECTOR: C-219

JUNCTION BLOCK SIDE

JUNCTION BLOCK

(REAR VIEW)

54DB014A

CONNECTOR: C-219

JUNCTION BLOCK SIDE

JUNCTION BLOCK

(REAR VIEW)

AC209836

201918 171615 1413 1211 10 9 8 7 6 5 4 3 2 1

AE

CONNECTOR C-219
(JUNCTION BLOCK SIDE)