2004 MITSUBISHI ENDEAVOR air conditioning

Fig. 27: Identifying Connectors C
-16 And C
-17
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2004 Mitsubishi Endeavor LS
2004 HVAC Heater Air Conditioning, Ventilation - Endeavor

Fig. 28: Identifying Connectors C
-104 And C
-122

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

DTC SET CONDITION
DTC B1021 is set if there is a short circuit in the air thermo sensor input
circuit. DTC B1022 is set if there is a defective connector connection, or if there is an
open circuit in the harness.
TECHNICAL DESCRIPTION (COMMENT)
CURRENT TROUBLE
The A/C-ECU, the air thermo sensor, or connector(s) or wiring between the
two may be defective.
PAST TROUBLE
2004 Mitsubishi Endeavor LS
2004 HVAC Heater Air Conditioning, Ventilation - Endeavor

If DTC B1021 or B1022 is stored as a past trouble, carry out diagnosis with
particular emphasis on wiring and connector(s) between the A/C-ECU and the
air thermo sensor. 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.
TROUBLESHOOTING HINT
Malfunction of connector. Malfunction of the harness. Malfunction of the air thermo sensor. Malfunction of the A/C-ECU.
DIAGNOSIS REQUIRED SPECIAL TOOL:

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, diagnose the CAN bus line.

Use scan tool MB991958 to diagnose the CAN bus lines.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Dia
gnose the CAN bus line.

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

Fig. 29: Connecting Scan Tool MB991958 To Data Link Connector

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

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA
.
Q: Is the check result satisfactory?

YES:
Go to Step 2.
NO:
Repair the CAN bus lines (Refer to
CAN BUS DIAGNOSTICS
TABLE
).
Then go to Step 7 .
STEP 2. Recheck for diagnostic trouble code.

Recheck if the DTC is set.
1. Erase the DTC.
2. Turn the ignition switch to "ON" position.
3. Check if the DTC is set.
Q: Is the check result satisfactory?

YES:
It can be assumed that this malfunction is intermittent.
Refer to
HOW TO USE TROUBLESHOOTING/ INSPECTION
SERVICE POINTS
.
NO:
Go to Step 3.
STEP 3. Using scan tool MB991958, check data list item 03: air thermo
sensor.

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 the
"LOCK" (OFF) position before connecting or
disconnecting scan tool MB991958.

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

Fig. 30: Connecting Scan Tool MB991958 To Data Link Connector

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

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA
.
2. Ignition switch: ON
3. Check the data list.
Item 03: air thermo sensor.
Check that the passenger room temperature matches the displayed
value on the scan tool while the engine is cold.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor within the specified range?

YES:
Replace the A/C-ECU. Then go to Step 7 .
NO:
Go to Step 4.
STEP 4. Check A/C-ECU connectors C-16, C-17 and air thermo sensor
connector C-122 for loose, corroded or damaged terminals, or terminals
pushed back in the connector.

Q: Are A/C-ECU connectors C-16, C-17 and air thermo sensor connector
C-122 in good condition?

YES:
Go to Step 5.
NO:
Repair or replace the connector. Refer to
HARNESS
CONNECTOR INSPECTION
. Then
go to Ste
p 7 .
NOTE: When this DTC is set and the system is fail-safe
status, the value of service data displays -6°C.

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

Fig. 31: Locating Connectors C
-16 And C
-17
Courtes
y of MITSUBISHI MOTOR SALES OF AMERICA
.

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