[Previous][Next]
P0531-00 Refrigerant Pressure Sensor Rationality correlation Fault
 
 
cautionBefore replacing the ECU, ensure that the CAN bus lines is normal.
 
 
DESCRIPTIONS OF MONITOR METHODS
  • A/C refrigerant pressure is monitored.
  • The electric compressor doesn't operate when the refrigerant pressure is less than 0.101 MPa (14.65 psi) or more than 2.812 MPa (407.847 psi).
  • The electric compressor can not work for battery cooling when the ambient temperature is less than 0°C (32°F) because amount of compressor oil recirculation is low, and it will lead breakage of compressor, so the monitor is not performed under the condition.
  • The monitor uses the hybrid battery temperature minimum value and engine intake air temperature instead of the ambient temperature to enable diagnostics.
  • PHEV A/C amp. monitors during the following condition;
    • Battery inlet refrigerant temperature 2°C (35.6°F) or more *1
    • Drive battery temperature minimum value 15°C (59°F) or more *2
    • Engine intake air temperature 15°C (59°F) or more
    note*1 When the battery inlet refirgerant temperature is less than 2°C (35.6°F), the electric compressor doesn't work for battery cooling.
    *2 The drive battery temperature minimum value is 10°C (50°F) higher than the ambient air temperature. The threshold for drive battery temperature minimum value is determined 15°C (59°F) in consideration of sensor allowance and A/D converter allowance.
 
 
MONITOR EXECUTION
Continuous
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
    • Battery inlet refrigerant temperature sensor
    • Drive battery temperature sensor
    • Intake air temperature sensor
 
 
DTC SET CONDITIONS
Logic Flow Chart
 
 
TROUBLE JUDGMENT
Check Condition
  • The heater PHEV A/C amp. power supply voltage is between 10 and 16 volts.
  • Battery inlet refrigerant temperature is 4°C (39°F) or more.
  • Drive battery temperature minimum value is 15°C (59°F) or more.
  • Intake air temperature is 15°C (59°F) or more.
Judgment Criterion
  • Change the A/C pressure sensor pressure is 2.812 MPa (407.847 psi) for 300 seconds or more.
Judgment Criterion
  • Change the A/C pressure sensor pressure is 0.101 MPa (14.65 psi) for 300 seconds or less.
 
 
OBD-II DRIVE CYCLE PATTERN
 
 
PROBABLE CAUSES
  • Malfunction of harness and connectors
  • Malfunction of refrigerant pressure sensor
  • Malfunction of PHEV A/C amp.
 
 
DIAGNOSIS
1.Check the power supply circuit voltage of the refrigerant pressure sensor
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Change the power supply mode of the electric motor switch to ON (READY indicator: ON).
(3) Measure the voltage between the PHEV A/C amp. connector (S5 terminal) and body ground.
OK : 1 V or less
Is the inspection result normal?
Repair harness or connector.
 
2.Check the signal circuit voltage of the refrigerant pressure sensor
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Change the power supply mode of the electric motor switch to ON (READY indicator: ON).
(3) Measure the voltage between the PHEV A/C amp. connector (SH_PRE terminal) and body ground.
OK : 1 V or less
Is the inspection result normal?
Repair harness or connector.
 
3.Check of open/short to ground circuit in S5 line between PHEV A/C amp. and refrigerant pressure sensor
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Check the continuity between the PHEV A/C amp. connector (S5 terminal) and body ground.
OK : No continuity
(3) Check the continuity between the PHEV A/C amp. connector (S5 terminal) and refrigerant pressure sensor.
OK : Continuity exists (2 Ω or less)
Is the inspection result normal?
Repair harness or connector.
 
4.Check of open circuit in SG line between PHEV A/C amp. and refrigerant pressure sensor
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Check the continuity between the PHEV A/C amp. connector (SG terminal) and refrigerant pressure sensor.
OK : Continuity exists (2 Ω or less)
Is the inspection result normal?
Repair harness or connector.
 
5.Check of open/short to ground circuit in SH_PRE line between PHEV A/C amp. and refrigerant pressure sensor
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Check the continuity between the PHEV A/C amp. connector (SH_PRE terminal) and body ground.
OK : No continuity
(3) Check the continuity between the PHEV A/C amp. connector (SH_PRE terminal) and refrigerant pressure sensor.
OK : Continuity exists (2 Ω or less)
Is the inspection result normal?
Repair harness or connector.
 
6.Check the refrigerant pressure sensor
Check the refrigerant pressure sensor. Refer to SIMPLE INSPECTION OF THE REFRIGERANT PRESSURE SENSOR.
Is the inspection result normal?
Replace refrigerant pressure sensor. Refer to REMOVAL AND INSTALLATION.
 
7.Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to OBD-II Drive Cycle - Pattern 1 OBD-II DRIVE CYCLE.
(2) Check the DTC.
Is the DTC set?
Replace PHEV A/C amp. Refer to Removal and Installation.
The trouble can be an intermittent malfunction. Refer to General Information - How to Use Troubleshooting/Inspection Service Points, How to Cope with Intermittent Malfunctions HOW TO COPE WITH INTERMITTENT MALFUNCTIONS.