PIT6112

Bulletin No.: PIT6112
Published date: 01/17/2024
Preliminary Information
PIT6112 P0534 Service High Voltage Diagnostic Tips
Models
Brand:
Model:
VIN:
Model Years:
from
Engine:
to
Transmissions:
Cadillac
LYRIQ
2023 - 2024
All
All
All
All
Chevrolet
Blazer EV
2024
All
All
All
All
Involved Region or Country North America
Condition
Service high voltage system message on the DIC along with a P0534
Cause
Refrigerant system not operating as well as intended
Correction:
Diagnostic tips for DTC P0534:
Start by performing an evacuation and recharge and make sure system has the correct refrigerant level.
Refer to SI for exact Specs and tolerances.
When doing evacuation and recharge use a clean oil catch bottle in the AC machine to look for any debris in system.
If the refrigerant level is found to be ok, then proceed to let vehicle set in the o -power mode for four hours preferably in a temperature stable area like
inside the shop.
Letting the vehicle set for four hours allows all the HVAC pressure and temperature sensors to equalize and get close to surrounding ambient
temperature.
A four hour cold soak makes it much easier to nd a failed or skewed sensor. The sensors we want to look at are in the Battery Energy Control Module
data and Body Control Module data.
Compare the data in the BECM, paying attention to the AC refrigerant temperature sensors 1-8. They should all be within 4 degrees of ambient
temperature.
The data that needs to be viewed in the BCM is the passenger compartment air temperature sensor voltage.
This sensor needs to be converted from voltage to temperature. After letting the vehicle set, compare all temperature sensors to one another, and if any
outliers are found, follow SI diagnostics for that sensor and replace the sensor as needed.
If all sensors look ok, update the BECM to the latest calibrations.
Note : For the BCM Passenger compartment air temperature sensor, see the chart below and use the blue line to convert from voltage to temperature.
This sensor may be up to 10 degrees o due to this conversion. This sensor is known as the B10E Sun Load and Ambient Light and Charge Indicator
Sensor in SI. If a faulty sensor is found, replace it as needed. If nothing is found, ensure the BECM has the latest calibrations.
Version History
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01/17/2024 - Created on.
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