B1324

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) monitors the high side refrigerant pressure via the A/C refrigerant pressure sensor. The PCM applies a 5.0 volt reference and a low reference (ground) to the sensor. When the pressure is low, the sensors voltage is low. When the pressure is high, the sensors voltage is high. The PCM sends the A/C pressure data to the body control module over the Class 2 serial data circuit. The body control module will not request A/C clutch engagement if the A/C pressure is too high.

CONDITIONS FOR RUNNING THE DTC
The body control module must be powered.

CONDITIONS FOR SETTING THE DTC
The A/C refrigerant pressure is greater than 2968 kPa (430 psi) for more than 500 milliseconds.

ACTION TAKEN WHEN THE DTC SETS
The body control module disables the A/C clutch.

CONDITIONS FOR CLEARING THE DTC
^ When the A/C refrigerant pressure drops to less than 1386 kPa (201 psi) the body control module will clear the current DTC and go to a history DTC. If A/C is still requested, the body control module will then enable the A/C clutch.
^ The history DTC will clear after 40 ignition cycles.
^ Use a scan tool in order to clear the DTC.

DIAGNOSTIC AIDS
^ If DTC B1324 is stored as a history code it indicates that the body control module did receive a high A/C refrigerant pressure message from the PCM. This code could be caused by an intermittent short to voltage on the A/C refrigerant pressure sensor signal circuit which would cause the PCM to set DTC P0530. The code could also be the result of an actual A/C refrigerant over-pressure condition.
^ It is possible for the refrigerant system pressure to exceed 2968 kPa ( 430 psi) during extended engine idle speed with A/C ON and ambient temperatures greater than 41°C (105°F). Other possible causes are:
- An overcharged A/C system
- A failed A/C refrigerant pressure sensor
- Blockage in a refrigerant line
- Debris in front of the A/C condenser
- Radiator or A/C condenser air shields missing or out of location
- Inoperative engine cooling fans
- Extended periods at idle in city traffic followed by rapid acceleration
- Aftermarket products affecting cooling system performance
^ If the concern is intermittent, refer to Testing for Intermittent and Poor Connections in Diagrams.

TEST

Steps 1-5: