A/C pressure transducer consists of piezoelectric element and it detects aircon refrigerant pressure. Piezoeletric type is more advantageous to obtain linear data of pressure than existing switch type. Thus, optimum control of aircon compressor and fan is realized and improved fuel efficiency follows with it.
P0533 is set when the voltage above 4.7V - maximum voltage of A/C pressure transducer signal - is detected for more than 0.6 sec.. This code is due to open or short in signal or ground circuit of A/C pressure transducer.
Item | Detecting Condition | Possible Cause | ||
DTC Strategy | ● Voltage monitoring | ● A/C pressure transducer circuit ● A/C pressure transducer component | ||
Enable Conditions | ● IG KEY "ON" | |||
Threshold Value | ● When output signal is above the maximum value ( above 4.7V ) | |||
Diagnostic Time | ● 0.6 sec. | |||
Fail Safe | Fuel cut | NO | ||
EGR Off | NO | |||
Fuel Limit | NO | |||
Check Lamp | NO | |||
Output signal(voltage) changes in accordance with the amount of refrigerant and the change of weather. Check if normal pressure change occurs in accordance with aircon compressor operation at normal pressure range shown in "Specification".
Connect Scantool to Data Link Connector (DLC).
Warm engine up to normal operating temperature.
Turn "OFF" electrical devices and A/C.
Monitor " A/C PRESSURE SENSOR " parameter on the scantool.
Specification : A/C "OFF" : 1200mV~1800mV
A/C "ON" : higher than A/C "OFF" pressure by more than 500mV
※ A/C Pressure sensor transducer voltage varies too much, therefore do not concern too much about the figure instead, check the rising tendancy of A/C Pressure transducer.
Electrical systems consist of a lot of harness and connectors, poor connection of terminals can cause various problems and damge of component.
Perform checking procedure as follows.
Check damage of harness and terminals : Check terminals for contact resistance, corrosion and deformation.
Check connecting condition of ECM and component connector : Check terminal seperation, damage of locking device and connecting condition between terminal and wiring.
Disconnect the pin which requires checking at male connector and insert it to the terminal at female connector for checking connecting condition. ( after checking, reconnect the pin at correct position. )
Is the problem found?
▶ Repair the trouble causing part and go to "Verification of Vehicle Repair".
▶ Go to "Power Circuit Inspection".
IG KEY "OFF", ENGINE "OFF"
Disconnect A/C pressure transducer connector.
IG KEY "ON"
Measure the voltage of A/C pressure transducer terminal 3.
Specification : 4.8V~5.1V
Is the measured voltage within the specification ?
▶ Go to "Signal Circuit Inspection".
▶ Repair open in power circuit of A/C pressure transducer and go to "Verification of Vehicle Repair".
Check signal circuit voltage
IG KEY "OFF", ENGINE "OFF"
Disconnect A/C pressure transducer connector and ECM connector.
IG KEY "ON"
Measure the voltage of A/C pressure transducer terminal 2.
Specification : 0.0V~0.1V
Is the measured voltage within the specification?
▶ Go to "Ground Circuit Inspection".
▶ Repair short to battery and go to "Verification of Vehicle Repair".
IG KEY "OFF", ENGINE "OFF"
Disconnect A/C pressure transducer connector.
IG KEY "ON"
Measure the voltage of A/C pressure transducer terminal 3. [ TEST "A" ]
Measure the voltage of A/C pressure transducer terminal 3 and terminal 1. [ TEST "B" ]
( terminal 3: Check + prove , terminal 1 : Check - prove )
Specification : the voltage difference between TEST "A" and TEST "B" is within 200mV
Is the measured voltage within the specification?
▶ Go to "Component Inspection"
▶ When "B" voltage is not detected : Repair open in ground circuit and go to "Verification of Vehicle Repair".
▶ When the voltage difference between "A" and "B" is above 200mV : Eliminate the causes of excessive resistance and go to "Verification of Vehicle Repair".
Aircon pressure sensor visual inspection
IG KEY "OFF", ENGINE "OFF"
Disconnect A/C pressure transducer connector.
Check if corrosion and contamination at aircon pressure sensor terminal is detected.
Check aircon pressure sensor connecting torque and aircon refrigerant leakage.
Does any problem is detected at aircon pressure sensor?
▶ Replace aircon pressure sensor and go to "Verification of Vehicle Repair".
▶ Go to "2. Check A/C pressure transducer waveform " as follows.
Check A/C pressure transducer waveform
IG KEY "OFF", ENGINE "OFF"
Connect A/C pressure transducer connector.
Connect oscilloscope to A/C pressure transducer connector terminal 2.
Monitor aircon pressure sensor waveform at idle as turning Aircon "ON".
Specification : Refer to "Siganl waveform ＆ data"
Is A/C pressure transducer waveform outputted correctly?
▶ Go to "Verification of Vehicle Rapair".
▶ Replace A/C pressure transducer and go to "Verification of Vehicle Rapair".
After a repair, it is essential to verify that the fault is corrected.
After connecting Scantool select "DIAGNOSTIC TROUBLE CODES(DTCs)" mode.
Clear recorded DTC using Scantool.
Drive the vehicle within DTC "Enable conditions" in "General information".
After selecting "DIAGNOSTIC TROUBLE CODES(DTCs)" mode and check if DTC is recorded again.
Are any DTCs recorded ?
▶ Go to the DTC guide of recorded NO. in Scantool.
▶ System operates within specification.
