P0534

DTC P0534

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor
DTC P0534
- Air Conditioning (A/C) Refrigerant Charge Low

Circuit/System Description

The AC compressor function is to provide refrigerant flow in the AC refrigerant loop to help cool down and dehumidify the for the cabin and help maintain the battery temperature. Rather than a more-typical pulley, the A/C compressor uses a 3-phase alternating current, high voltage electric motor to operate. It has an on-board inverter that takes High Voltage direct current from the vehicle's High Voltage Battery and inverts it to alternating current for the motor. The AC compressor shall be activated when any of the three following events occur:

* The customer selects ECO or Comfort.
* The HVAC system is fan only but the customer selects defrost mode
* The High Voltage Battery Thermal System requests the AC compressor on to help maintain the battery temperature

The Hybrid Powertrain control module 2 (HPCM2) uses values from the A/C refrigerant pressure transducers, A/C refrigerant thermistor, ambient air temperature sensor , cabin climate control request, battery cell temperature sensors, battery coolant temperature sensors and battery coolant pumps to determine the speed at which the compressor will operate. This message is sent from the HPCM2 to the A/C compressor control module via GM LAN message.

When in battery active cooling mode, the HPCM2 controls the RESS pump and the RESS valve and requests the AC compressor to turn faster than in typical use to determine whether the refrigerant in the system is low.

Conditions for Running the DTC

DTC P0534 Case 1
* System voltage is equal to or greater than 9V
* the ACCM has 300V
* The ACCM compressor motor is running for at least 30 seconds.
* Must be in battery active cooling mode for at least 1 minute
* The following DTCs must not be set: P0CE0; P0CE2; P0CE3; P0CE6; P0CE7; P1CE7; P1CE8, P0C47; P0C4A, P1F18, P0C44, P0C45, P0C43,P0CD6, p0CD7, P0CD8, P0071; P0072; P0073

DTC P0534 Case 2
* System voltage is equal to or greater than 9V
* AC compressor off for greater than 240 seconds
* OAT greater than 15C.
* The following DTCs must not be set: P2516, P2517, P2518, P0606, P0071,P0072, P0073

DTC P0534 Case 3
* System voltage is equal to or greater than 9V
* AC compressor on for greater than 240 seconds
* OAT greater than 5C.
* The following DTCs must not be set: P2516, P2517, P2518, P0606, P0071,P0072, P0073

DTC P0534 Case 4
* System voltage is equal to or greater than 9V
* AC compressor off for greater than 240 seconds
* The following DTCs must not be set: P0531,P0532, P0533,P0606, P0071; P0072; P0073

Conditions for Setting the DTC

DTC P0534 Case 1

The difference between the RESS coolant outlet temperature and RESS coolant inlet temperature within the evaluation period of 120 seconds is less than a calibrated amount of 3 to 5 degrees C. The required temperature difference requirement is based on outside air temperature and whether the cabin blower is on or off.

DTC P0534 Case 2

Low side pressure is a less than a designated value based on OAT.

DTC P0534 Case 3

Low side pressure is less than 150 kPa for OAT greater than 5C.

DTC P0534 Case 4

High side pressure is greater than 5000 kPa

Action Taken When the DTC Sets

The ACCM is disabled.

Conditions for Clearing the DTC

P0534 is a type B DTC.

Reference Information
Schematic Reference

HVAC Schematics HVAC - Automatic
Connector End View Reference

Component Connector End Views Connector End Views By Name
Description and Operation

Automatic HVAC Description and Operation HVAC - Automatic
Electrical Information Reference

* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference

Control Module References Control Module References for scan tool information

Diagnostic Aids

P1EC3 is the RESS heater circuit fault DTC. It diagnoses three different circuit faults (short-ground, short-battery, open circuit); one of these, short to ground, could cause the RESS heater to activate and could cause P0534 to set. Diagnose P1EC3 before diagnosing P0534.

Circuit/System Verification

Verify that DTC P0534 is set.

If the DTC is set, Refer to Leak Testing Leak Testing.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.