Diagnostic article Generic OBD-II
P0AAF: Very cold inlet-air data can be the battery sensor’s high-circuit fault
Read the GM P0AAF inlet-air limit and understand why it differs from the cold-soak plausibility monitor.
Read before applying this article
Documented application
GM 2010 10OBDG10 Hybrid Diagnostics, only the cited controller and monitor. These are historical calibration examples; individual vehicle, engine and hardware applicability is not established.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
P0AAF is the battery inlet-air sensor's circuit-high fault in the cited GM controller. The documented temperature criterion is below −45°C. This is an extreme input-limit check, not the inlet-versus-outlet comparison used by P0AAD.
Run-state monitoring differs from cold-soak evaluation
The source requires battery-controller run mode, suitable low-voltage supply and no P0A1F controller-performance fault. It uses 30 failing samples out of 40 at 100ms intervals. The row does not require the eight-hour off period specified for the separate plausibility test.
That distinction matters if the code appears during an active trip. A diagnostic explanation that says P0AAF can only be evaluated after an overnight soak would import conditions from the wrong monitor.
Preserve the exact input
Save inlet-air temperature and its validity status, not merely ambient temperature or the battery's minimum module temperature. Those measurements may provide context, but the source does not establish that they share a sensor or conversion.
The code does not identify a specific open wire, connector or sensor replacement. The physical circuit and fault location must be established using the vehicle-specific battery service information. A qualified technician should follow the correct isolation and access procedure around high-voltage equipment. An extreme cold indication is a signal diagnosis and must not be treated as evidence that the battery assembly is safe to handle.
Source and applicability
GM 2010 10OBDG10 Hybrid Diagnostics, only the cited controller and monitor. These are historical calibration examples; individual vehicle, engine and hardware applicability is not established. GM PDF, page 237.
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
Hybrid/EV Battery Pack Air Temperature Sensor A Circuit High
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT