P0AF0 on GMC: How to Diagnose & Fix
Drive Motor Inverter Temperature Sensor 'A' Circuit High
1 GMC model · 1 documented issue
P0AF0 on GMC by model: symptoms, diagnosis and fix
Some Hummer EV SUVs experience slower-than-expected DC fast charging speeds and intermittent charge port communication failures. The SUV's 800V charging is rated at up to 300 kW (the pickup is rated at 350 kW), but software limitations and battery temperature management can reduce speeds significantly. The charge port door actuator can also fail, preventing the port from opening. CCS connector fit issues at some public charging stations cause the vehicle to reject the charge session.
Common Symptoms
- DC fast charging capping at 100-150 kW instead of the rated 300 kW
- Charge port door not opening
- Charging session ending prematurely
- Unable to initiate charging at some stations
- Battery preconditioning not activating before arrival at charger
How to Fix
Pre-condition the battery for DC fast charging by enabling the "target charge station" feature in navigation — this warms the battery to optimal temperature before arrival. Ensure the latest OTA software update is installed, as GM has improved charging algorithms. For charge port door issues, the actuator can be replaced under warranty. Try multiple charger brands if one consistently fails to connect.
Sources for this issue (2)
P0AF0 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0AF0 mean on a GMC?
P0AF0 stands for "Drive Motor Inverter Temperature Sensor 'A' Circuit High." This hybrid/electric powertrain code sets when the control module sees the signal from the drive motor inverter temperature sensor 'A' circuit above its expected range (typically an open circuit or a short to voltage). The inverter's temperature reading is used to protect the power electronics, so when the module cannot trust it, it may limit electric drive power and illuminate a hybrid/EV warning or check engine light. Diagnose with the factory service information and observe high-voltage safety precautions. On GMC it is documented across 1 model: Hummer EV SUV.
What are the most common causes of P0AF0?
The most common causes of P0AF0 are: Open or high-resistance inverter temperature sensor circuit, Sensor signal circuit shorted to voltage, Failed drive motor inverter temperature sensor (often internal to the inverter/power module), Damaged, loose or corroded inverter connector, Faulty drive motor control module / inverter assembly. The specific cause varies by vehicle.
How much does it cost to fix P0AF0 on a GMC?
Repair costs vary widely with the root cause and GMC model; each issue on this page carries its own estimate where one is published.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.