2004 MITSUBISHI ENDEAVOR Ac pressure sensor

CURRENT TROUBLE
The A/C-ECU, the A/C pressure sensor or the connector(s) or wiring between
the two may be defective
PAST TROUBLE
If DTC B1031 or B1032 is stored as a past trouble, carry out diagnosis with
particular emphasis on wiring and connector(s) between the A/C-ECU and the
A/C pressure 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 A/C pressure 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)
MB991658: Test Harness Set 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 i
gnition switch to "ON"
position.

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

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 04: A/C pressure
sensor.

1. Connect scan tool MB991958 to the data link connector.
2. Assemble a manifold gauge onto the high pressure service valve.
3. Turn ON the engine and then turn ON the air conditioner switch.
4. Check the data list.
Item 04: A/C pressure sensor. Check that the refrigerant pressure matches the displayed value on the
scan tool.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor within the specified range?

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

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA
.
STEP 4. Check A/C pressure sensor connector A-28 for loose, corroded or
damaged terminals, or terminals pushed back in the connector.

Q: Is A/C pressure sensor connector A-28 in good condition?

YES:
Go to Step 5.
NO:
Repair or replace the connector. Refer to
HARNESS
CONNECTOR INSPECTION
. Then go to Step 8 .
Fig. 44: Locating Connector A
-28
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

STEP 5. Check the A/C
pressure sensor
.

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

1. Assemble a gauge manifold on the high pressure service valve.
2. Disconnect the A/C pressure sensor connector and connect special tool
MB991658 as shown in the illustration.
3. Turn ON the engine and then turn ON the air conditioner switch.
Fig. 45: Checking A/C Pressure Sensor

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

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

Fig. 46: Connecting Special Tool (MB991658) To Harness Side

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

4. At this time, check to see that the voltage of A/C pressure sensor terminal
No.2 reflects the specifications of the figure.
Q: Is the A/C pressure sensor in good condition?

YES:
Go to Step 6.
NO:
Replace the A/C pressure sensor. Then go to Step 8 .
NOTE: The allowance shall be defined as +/-5%.

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

Fig. 47: A/C Pressure Sensor Terminal Graph

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

STEP 6. Check A/C-ECU connectors C-16, C-17 for loose, corroded or
damaged terminals, or terminals pushed back in the connector.

Q: Are A/C-ECU connectors C-16, C-17 in good condition?

YES:
Go to Step 7.
NO:
Repair or replace the connector. Refer to
HARNESS
CONNECTOR INSPECTION
. Then
go to Ste
p 8 .

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

STEP 7. Check the wiring harness between A/C-ECU connector C-16
(terminal 12), C-17 (terminals 34 and 26) and A/C pressure sensor
connector A-28 (terminals 3, 1 and 2).

Fig. 49: Locating Connector A
-28
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

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

Fig. 51: Locating Connector C
-31
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Q: Is the wiring harness between A/C-ECU connector C-16 (terminal 12),
C-17 (terminals 34 and 26) and A/C pressure sensor connector A-28
(terminals 3, 1 and 2) in good condition?

YES:
Replace the A/C-ECU. Then go to Step 8.
NO:
Repair the wiring harness. Then go to Step 8.
STEP 8. Recheck for dia
gnostic trouble code
.
NOTE: Also check intermediate connector C-31 for loose,
corroded, or damaged terminals, or terminals pushed
back in the connector. If intermediate connector C-31 is
damaged, repair or replace the connector as described
in HARNESS CONNECTOR INSPECTION
.

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