2007 Liberty KJ Factory Service Manual 9 - ENGINE

P0533-A/C PRESSURE SENSOR CIRCUIT HIGH





For a complete wiring diagram Refer to Section 8W.



Possible Causes
 
(C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
 
(C18) A/C PRESSURE SIGNAL CIRCUIT OPEN
 
(C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO THE (K301) 5-VOLT SUPPLY CIRCUIT
 
(K310) SENSOR GROUND CIRCUIT OPEN
 
A/C PRESSURE TRANSDUCER
 
CAN C BUS CIRCUIT OPEN OR SHORTED
 
BCM
 
PCM
 


Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).



Diagnostic Test

1. A/C PRESSURE TRANSDUCER VOLTAGE ABOVE 4.9 VOLTS

NOTE: Diagnose any CAN C Bus Communication DTCs before continuing.

NOTE: Make sure the A/C refrigerant System is properly charged per Service Information.


Start the engine.
With a scan tool, read the A/C Pressure Sensor voltage.

Is the voltage above 4.9 volts?

Yes


No

2. A/C PRESSURE TRANSDUCER



Turn the ignition off.
Disconnect the A/C Pressure Transducer harness connector.
Connect a jumper wire between the (C18) A/C Pressure Signal circuit and the (K310) Sensor ground circuit in the Transducer harness connector.
Ignition on, engine not running.
With the scan tool, monitor the A/C Pressure Transducer voltage.

Is the voltage below 1.0 volt with the jumper wire installed?

Yes


No

3. (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE



Turn the ignition off.
Disconnect the C2 BCM harness connector.
Ignition on, engine not running.
Measure the voltage on the (C18) A/C Pressure Signal circuit in the A/C Pressure Transducer harness connector.

Is the voltage above 5.2 volts?

Yes


No

4. (C18) A/C PRESSURE SIGNAL CIRCUIT OPEN



Turn the ignition off.
Measure the resistance of the (C18) A/C Pressure Signal circuit from the A/C Pressure Transducer harness connector to the C2 BCM harness connector.

Is the resistance below 5.0 ohms?

Yes


No

5. (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO THE (K301) 5-VOLT SUPPLY CIRCUIT



Measure the resistance between the (C18) A/C Pressure Signal circuit and the (K301) 5-volt Supply circuit in the A/C Pressure Transducer harness connector.

Is the resistance below 5.0 ohms?

Yes


No

6. (K310) SENSOR GROUND CIRCUIT OPEN



Disconnect the C2 BCM harness connector.
Measure the resistance of the (K310) Sensor ground circuit from the A/C Pressure Sensor harness connector to the C2 BCM harness connector.

Is the resistance below 5.0 ohms?

Yes


No

7. BCM

NOTE: Before continuing, check the BCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.


Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Were there any problems found?

Yes


No