technical data MITSUBISHI ENDEAVOR 2004 Service Repair Manual

DTC U1120: FAILURE INFORMATION ON POWERTRAIN CONTROL MODULE (RELATED TO ENGINE)TROUBLE JUDGMENT The A/C-ECU receives engine control system-related signal from the powertrain
control module by the CAN bus lines. If a fail-safe related data is contained in the
signal from the powertrain control module, DTC U1120 will be stored. TECHNICAL DESCRIPTION (COMMENT)
CURRENT TROUBLE
The wiring harness wire or connectors may have loose, corroded, or damage
terminals, or terminals pushed back in the connector, the powertrain control
module, or the A/C-ECU may be defective.
PAST TROUBLE
If DTC U1120 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 powertrain control module, and the power supply system to the
powertrain control module. 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.
CAUTION: If DTC U1120 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.
CAUTION: The engine control system- related DTC may be set
when DTC U1120 is set (For details refer to
INTERSYSTEM AFFILIATED DTC REFERENCE
TABLE
). Diagnose the engine control system first
when the engine control system- related DTC is set.
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.

2004 Mitsubishi Endeavor LS
2004 HVAC Heater Air Conditioning, Ventilation - Endeavor

Fig. 22: Identifying Connectors

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
CIRCUIT OPERATION The Immobilizer-ECU is energized by the MFI relay when the ignition switch is
turned "ON". The PCM transmits a signal from scan tool MB991958 to the
immobilizer-ECU as it is. In the same way, a signal from the immobilizer-ECU is
also transmitted to scan tool MB991958 as it is. TECHNICAL DESCRIPTION (COMMENT)
This malfunction may be caused by a defective immobilizer-ECU, PCM, or a
defect in the communication line between the immobilizer-ECU and PCM. If
this malfunction appears when the MFI system and scan tool MB991958 can
communicate each other, MFI system DTC P0513 will reset. If the MFI system is normal, the MFI relay can be determined as normal. In
addition, if the MFI system and scan tool MB991958 can communicate each
other, the circuits between the data link connecto
r and the PCM can determined

2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Ignition Switch - Endeavor

Fig. 43: Identifying Connectors

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
CIRCUIT OPERATION The Immobilizer-ECU is energized by the MFI relay when the ignition switch is
turned "ON". The PCM transmits a signal from scan tool MB991958 to the
immobilizer-ECU as it is. In the same way, a signal from the immobilizer-ECU is
also transmitted to scan tool MB991958 as it is. TECHNICAL DESCRIPTION (COMMENT)
This malfunction may be caused by a defective immobilizer-ECU, PCM, or a
defect in the communication line between the immobilizer-ECU and PCM. If
this malfunction appears when the MFI system and scan tool MB991958 can
communicate each other, MFI system DTC P0513 will reset. If the MFI system is normal, the MFI relay can be determined as normal. In
addition, if the MFI system and scan tool MB991958 can communicate each
other, the circuits between the data link connector and the PCM can determined
as normal.

2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Ignition Switch - Endeavor

YES: Register the password (secret code) and encrypted code ON
-
VEHICLE SERVICE
.
NO: Replace the PCM. Then register the password (secret code) and
encrypted code (Refer to ON
-VEHICLE SERVICE
).
INSPECTION PROCEDURE 2: THE IGNITION KEY CANNOT BE REGISTERED TECHNICAL DESCRIPTION (COMMENT) The ignition key transponder or the immobilizer-ECU is suspected to be defective. TROUBLESHOOTING HINTS
Malfunction of the ignition key Malfunction of immobilizer-ECU
DIAGNOSIS Required Special Tools:
MB991958: Scan 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 scan tool MB991958, read the diagnostic trouble code.
Use scan tool MB991958 to check if DTC 11 is set.
1. Connect scan tool MB991958 to the data link connec
tor.
CAUTION: To prevent damage to scan tool MB991958,
always turn the ignition switch to "LOCK" (OFF)
position before connecting or disconnecting
scan tool MB991958.

2004 Mitsubishi Endeavor LS
2004 BODY & ACCESSORIES Ignition Switch - Endeavor