DTC 45

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

Pressure Sensor System Circuit:

CIRCUIT OPERATION
The AWD-ECU receives accumulator pressure information from the pressure sensor to control the electric pump.

DTC SET CONDITIONS
DTC 45 is set when the output signal from the pressure sensor is below 0.2 volts.

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
^ Malfunction of the pressure sensor
^ Damaged harness and connector
^ Malfunction of the AWD-ECU

DIAGNOSIS
Required Special Tool:
^ MB991958: Scan Tool (M.U.T-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?
YES: It can be assumed that this malfunction is intermittent.
NO: Go to Step 2.

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?
YES: Go to Step 3.
NO: Go to Step 5.

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?
YES: Go to Step 4.
NO: Repair or replace the damaged components.

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?
YES: It can be assumed that this malfunction is intermittent.
NO: Replace the AWD-ECU.

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?
YES: Go to Step 6.
NO: Repair or replace the damaged components.

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?
YES: Replace the pressure sensor.
NO: Repair or replace the harness wire.