P1F0C
DTC P1F0A-P1F0D
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 P1F0A
- Electric A/C Compressor Control Module A/C Compressor Motor Current Feedback Circuit Low
DTC P1F0B
- ACCM Motor drive circuit fault
DTC P1F0C
- Electric A/C Compressor Control Module A/C Compressor Motor Current Feedback Circuit High
DTC P10FD
- A/C Compressor Motor Start-Up Current Performance
Circuit/System Description
The AC compressor function is to provide refrigerant flow in the AC refrigerant loop to help cool down the cabin, help dehumidify the air in a defrost mode 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 pushes the AC button
* The HVAC control, in AUTO mode, requests the electric AC compressor on to help in cooling the cabin or removing moisture in the defrost mode
* The High Voltage Battery Thermal System requests the AC compressor on to help maintain the battery temperature
The VICM uses values from the A/C refrigerant pressure transducers, A/C refrigerant thermistor, duct temperature sensors, ambient air temperature sensor , passenger compartment temperature sensor, evaporator temperature sensor, 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 VICM to the A/C compressor control module via GM LAN message.
AC Compressor has a motor start up procedure that can take a variable length of time to run to bring the motor up to requested speed. Length of time is dependent on external conditions such as underhood temperature and high side pressure. In hotter conditions, the motor start up time will be longer. The ACCM monitors an internal parameter known as the DC Link Current which is based off DC Input Current. It is not possible to measure this parameter externally.
Conditions for Running the DTC
DTC P1F0A
* System voltage is above 9 V.
* Vehicle is in Run Mode or Charging Mode with RESS Thermal Active
* Compressor is in Start Up Mode
DTC P1F0B
* System voltage is above 9 V.
* Vehicle is in Run Mode or Charging Mode with RESS Thermal Active
* Compressor is in Start Up Mode
DTC P1F0C
* System voltage is above 9 V.
* Vehicle is in Run Mode or Charging Mode with RESS Thermal Active
* Compressor is in Start Up Mode
DTC P1F0D
* System voltage is above 9 V.
* Vehicle is in Run Mode or Charging Mode with RESS Thermal Active
* Compressor is in Start Up Mode
Conditions for Setting the DTC
DTC P1F0A
* ACCM Temperature is greater than 85 deg C and compressor motor speed does not reach to 1800 rpm within 20sec. after the start of spinning
* ACCM Temperature is less than or equal to 85 degC and ACCM compressor motor speed does not reach to 1800 rpm and ACCM compressor motor spins for 1 minute after IGBT temperature raises 10 deg C
DTC P1F0B
Any ACCM phase current (U/V/W) >= -1A during initial motor startup process
DTC P1F0C
ACCM DC link Current is less than 2.5 Amps for 6 seconds
DTC P1F0D
ACCM DC link Currentt is greater than 36.7 Amps for 6 seconds
Action Taken When the DTC Sets
The ACCM is disabled but will retry once the Compressor Speed Request goes to 0 rpm and a new Speed Request > 0 rpm is sent.
Conditions for Clearing the DTC
The DTC's can be cleared by sending a clearing code request with the scan tool and cycling the ignition, with bus sleep
Reference Information
Schematic Reference
HVAC Schematics HVAC - Automatic
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1 A4
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
Circuit/System Verification
1. Verify that DTC DTC P0F0A-P1F0D is not set.
• If the DTC is set, verify that the A/C compressor control module and the VICM (HPCM2) have the latest software and reprogram the modules if needed
2. If DTC sets again replace the A/C compressor control module.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
Air Conditioning and Drive Motor Battery Cooling Compressor Replacement Air Conditioning and Drive Motor Battery Cooling Compressor Replacement