P04FB fault code: what 6 owners reported

Roughly 6 months ago, the check engine light came on in my 2025 Chevrolet Equinox RS, which had under 20,000 miles on it at the time. I purchased an OBD scanner to run a diagnostic test, which came back with error code P04FB (Crankcase Ventilation Hose Connection Pressure Sensor Issue). I called the dealership that sold me the vehicle, and they ran their own diagnostics. They encountered the same error code, and ended up replacing the "faulty" crankcase ventilation pressure sensor, which was covered under warranty. Less than a week after they replaced the sensor, the check engine light came back on. I re-ran my OBD scanner, and it showed the same exact error code as before. Basically, the…

I am experiencing a recurring P04FB diagnostic trouble code on my 2023 GMC Acadia, related to the crankcase pressure sensor. GM issued Bulletin No. PIP5841C, which attributes the issue to moisture buildup freezing inside the sensor. Their recommended fix is to remove the sensor, blow out any moisture, and reinstall it. However, this is not a permanent solution—the code returns within days, suggesting an inherent design flaw in the PCV system. Additionally, the replacement sensor (Part #12718935) is on national backorder, making it impossible to obtain. Many owners across multiple GM models using this engine (such as the Chevrolet Blazer and Cadillac XT4) are experiencing the same problem…

This is a 2025 vehicle with 25,000 miles and the Check Engine Soon light stays illuminated due to a faulty PCV Valve or possibly a poorly designed crankcase. The engine code is P04FB and is commonly found as an issue when you do a search. As a safety precaution, the vehicle is programmed to not allow the remote start to work as designed when the engine light is on so this issue affects the overall functionality of the car. Having spoken with the dealership, they report seeing that engine code often and that the part is on backorder. The dealership seems to think it's the crankcase causing the issue and not the PCV Valve as the fix they have been ordering for them is the case. It will…

The contact owns a 2021 GMC Acadia. The contact stated while driving at an undisclosed speed, the check engine warning light illuminated and DTC: P04FB; was displayed. The vehicle was taken to the dealer where it was diagnosed with moisture of the crank case. The vehicle was repaired. The contact stated that the failure was a quick fix and was covered under the warranty. The contact stated that the failure had occurred several times and was covered under warranty. The contact was informed that there was no fix for the failure. The manufacturer was not made aware of the failure. The failure mileage was approximately 37,000.

Bought vehicle in October 2024. About 5 hours after we purchased vehicle the check engine light came on, dealership did reset and everything checked out to be safe and sent us on our way. Fast forward to January (do not remember date) check engine light came on again, this time took it to auto zone to hook the car up to the scanner, it did give an error code of P04FB which is a crankcase ventilation sensor. From auto zone we did take it back to the dealership and the had the same code as auto zone. Dealer ship did reset and acknowledged that Chevy was “working on it” but no fix is available. Everything seemed to be ok until 6/5/2025 and the another time in June when the check engine light…

The contact owns a 2025 Chevrolet Equinox. The contact stated that while driving at various speeds, a yellow check engine warning light illuminated. The vehicle was taken to the dealer where it was diagnosed, and contact was provided DTC: P04FB (Crankcase Ventilation Systems Pressure Sensor Issue). The contact was informed that the Manufacturer's engineers were working on an improved solution. The vehicle was not repaired. The dealer cleared the code. The contact stated that the failure persisted. The manufacturer was not made aware of the failure. The failure mileage was approximately 5,000.