Mitsubishi Montero Sport (2004+). Manual - part 316

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-677

STEP 6. Check for harness damage between power 
steering pressure switch connector A-76 (terminal No. 1) 
and PCM connector C-90 (terminal No. 52).
Q: Is the harness wire in good condition?

YES : Replace the PCM. Then go to Step 7.
NO :  Repair it. Then go to Step 7.

AK200031

1

AB

CONNECTOR: A-76

A-76

HARNESS CONNECTOR:
COMPONENT SIDE

AK103762

42

43

48

49

50

51

52

53

54

55

56

57

46 45 44

58

59

60

61

62

63

64

65

66

47

41

AB

CONNECTOR: C-90

C-90(GR)

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-678

STEP 7. Using scan tool MB991958, check data list item 27: 
Power Steering Pressure Switch.

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 to the data link connector.
(2) Start the engine and run at idle.
(3) Set scan tool MB991958 to the data reading mode for item 

27, Power Steering Pressure Switch.

• If the steering wheel is stopped while idling, "OFF" will 

be displayed.

• If the steering wheel is steered while idling, "ON" will be 

displayed.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the switch operating properly?

YES : The procedure is complete.
NO :  Repeat the troubleshooting.

AK303629AB

MB991911

MB991827

MB991824 

16-PIN

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-679

DTC P1603: Battery Backup Line Malfunction

.

TECHNICAL DESCRIPTION

• The PCM is checks the open circuit of battery 

backup line.

NOTE: When the system detects an open circuit in 
the battery backup line, it makes 1 failure judgment 
of other diagnostic trouble codes (DTCs).

.

DESCRIPTIONS OF MONITOR METHODS
Battery backup line voltage is under specified value.

.

MONITOR EXECUTION
Continuous

.

MONITOR EXECUTION CONDITIONS (Other 
monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• Not applicable

Sensor (The sensor below is determined to be 

normal)

• Not applicable

.

AK200451

Battery Backup Circuit

WHITE-

BL

ACK

BATTERY
BACKUP

POWERTRAIN CONTROL
MODULE (PCM)

FUSIBLE
LINK(12)

66

47

41

42 43

48 49 50 51 52 53 54 55 56 57

46

45

44

58

59

60 61 62 63

64 65 66

C-90
(MU803781)

AK103738AC

CONNECTOR: C-90

PCM

C-90(GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-680

LOGIC FLOW CHART

.

Check Conditions

• Starting sequence was completed.

• Battery positive voltage is higher than 10 volts.

Judgement Criteria

• Battery backup line voltage has continued to be 6 

volts or lower for 2 seconds.

.

OBD-II DRIVE CYCLE PATTERN
None.

.

TROUBLESHOOTING HINTS (The most likely 
causes for this code to be set are: )

• Open or shorted battery backup line, harness 

damage or connector damage.

• PCM failed.

NOTE: When the engine is started with the IOD or 
storage connector disconnected, the PCM judges 
that an open circuit has occurred in the battery 
backup line. Consequently, the service engine 
soon/malfunction indicator lamp illuminates and the 
DTC is stored in memory.

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I

• MB991827: USB Cable

• MB991911: Main Harness B

START

MONITORING
CONDITIONS

CIRCUIT VOLTAGE

MALFUNCTION

CONTINUOUS

FAILURE FOR 2secs

NO

YES

YES

NO

< 6V

END

GOOD

NO

YES

AK301454