Sensor MITSUBISHI ENDEAVOR 2004 Service Repair Manual

Q: Is the ambient air temperature sensor in good condition?

YES:
Replace the A/C-ECU. Then go to Step 7.
NO:
Replace the ambient air temperature sensor. Then go to Step 7.
STEP 7. Recheck for diagnostic trouble code.

Check again if the DTC is set.
1
.Co
nnect
sca
n too
l MB
991958
to the data
link
connect
or
Fig. 24: Sensor Terminal Resistance Graph

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

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

YES:
The procedure is complete.
NO:
Return to Step 1 .
DTC B1021, B1022: AIR THERMO SENSOR SYSTEM
2004 Mitsubishi Endeavor LS
2004 HVAC Heater Air Conditioning, Ventilation - Endeavor

Fig. 26: View Of Air Thermo Sensor Circuit

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

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

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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.

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.
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.

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.
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.

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Fig. 32: Locating Connector C
-122

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STEP 5. Check the wiring harness between A/C-ECU connector C-16
(terminal 20), C-17 (terminal 24) and air thermo sensor connector C-122
(terminals 1 and 2)
.

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

Q: Is the wiring harness between A/C-ECU connector C-16 (terminal 20),
C-17 (terminal 23) and air thermo sensor connector C-122 (terminals 1
and 2) in good condition?

YES:
Go to Step 6.
NO:
Repair the wiring harness. Then go to Step 7 .
STEP 6. Check the air thermo sensor.

1. Disconnect the air thermo sensor connector C-122.
NOTE: Also check joint connector C-104 for loose, corroded,
or damaged terminals, or terminals pushed back in the
connector. If joint connector C-104 is damaged, repair
or replace the connector as described in HARNESS
CONNECTOR INSPECTION
.

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

Fig. 35: Locating Connector C
-122

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2. Measure the resistance between connector terminals 1 and 2 under at least
two different temperatures. The resistance values should generally match
those in the graph.
Fig. 36: Terminal Resistance Graph

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Q: Is the air thermo sensor in good condition?

YES:
Replace the A/C-ECU. Then go to Step 7.
NO:
Re
place the air thermo sensor. Then
go to Ste
p 7.
NOTE: The temperature at the check should not exceed the
range in the graph.

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