DTC 45: Pressure Sensor System (Open Circuit or Short Circuit): Diagnosis

Required Special Tool:

MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991911: Main Harness B

STEP 1. Using scan tool MB991958, check data list item 18: Pressure Sensor.
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.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Actuator test item 04: Drive the electric pump.
4. Set scan tool MB991958 to the data reading mode.
  - Item 18: Pressure Sensor
    - While the electric pump is driven, 1.0 - 1.6 MPa is displayed.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
1. YES : It can be assumed that this malfunction is intermittent. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION .
2. NO : Go to Step 2.
Fig 1: Connecting Scan Tool To Data Link Connector Step 1
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 2. Measure the pressure sensor system voltage at AWD-ECU connector C-138 by backprobing.
1. Turn the ignition switch to the "ON" position.
2. Measure the voltage between AWD-ECU connector C-138 terminal 32 and ground by backprobing.
  - The voltage should measure between 0.5 and 1.5 volts.
3. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 0.5 and 1.5 volts?
1. YES : Go to Step 3.
2. NO : Go to Step 5.
Fig 2: Identifying AWD-ECU Connector C-138 Terminals
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 3: Measuring Voltage Between AWD-ECU Connector C-138 Terminal 32 And Ground
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 3. Check AWD-ECU connector C-138 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connector and terminals in good condition?
1. YES : Go to Step 4.
2. NO : Repair or replace the damaged components. Refer to HARNESS CONNECTOR INSPECTION .
Fig 4: Identifying AWD-ECU Connector C-138 Terminals
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 4. Using scan tool MB991958, check data list item 18: Pressure Sensor.
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.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Actuator test item 04: Drive the electric pump.
4. Set scan tool MB991958 to the data reading mode.
  - Item 18: Pressure Sensor
    - While the electric pump is driven, 1.0 - 1.6 MPa is displayed.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
1. YES : It can be assumed that this malfunction is intermittent. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION .
2. NO : Replace the AWD-ECU.
Fig 5: Connecting Scan Tool To Data Link Connector Step 4
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 5. Check pressure sensor connector B-30 and AWD-ECU connector C-138 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connectors and terminals in good condition?
1. YES : Go to Step 6.
2. NO : Repair or replace the damaged components. Refer to HARNESS CONNECTOR INSPECTION .
Fig 6: Identifying Pressure Sensor Connector B-30 Terminals
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 7: Identifying AWD-ECU Connector C-138 Terminals
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 6. Check the harness for open circuit or short circuit to ground between pressure sensor connector B-30 terminal 2 and AWD-ECU connector C-138 terminal 32.
Q: Is the harness wire in good condition?
1. YES : Replace the pressure sensor.
2. NO : Repair or replace the harness wire.
Fig 8: Identifying Pressure Sensor Connector B-30 Terminals
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 9: Identifying AWD-ECU Connector C-138 Terminals
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.