Fuel PCV Compensation Value reset in the OBD Scanner
The fuel PCV (Pressure Control Valve) compensation value is a parameter used by the ECM to correct fuel delivery based on the performance of the PCV system.
The PCV system is designed to control crankcase pressure by allowing blow-by gases (gases that get past the piston rings and escape into the crankcase) to be drawn into the intake manifold for burning.
With time, this system can be blocked or made too small leading to an increased pressure in the crankcase. Consequently, this pressure may affect how fuel gets delivered within such systems causing a gross imbalance between air and gas components thereof.
To compensate for this difference in pressure, maintain proper air-fuel mixture for optimum combustion and emission controls, ECM applies a Fuel PCV Compensation Value as a correction factor.
Usually, after changing or servicing PCV system parts resetting of Fuel PCV Compensation value using OBD (On-Board Diagnostics) scanner is done. This action makes ECM so that it remembers new conditions of its PCV system hence accurate fuel delivery and efficient engine operation are achieved.
Resetting Fuel PCV Compensation Value varies from one vehicle to another and the scanner being used. One normally has to go through the menu of the scanner to find reset function of this value, which involves following instruction prompts on the screen.
Upon resetting, during subsequent driving cycles, the ECM will begin learning and adjusting its fuel PCV compensation value based on performance of a new PCV system.
Instruction to Access the Fuel PCV Compensation Value reset in the OBD Scanner
The Fuel PCV Compensation Value reset can be accessed by following this instruction.
- Open your OBD scanner.
- Select Local Diagnose if you are using Launch X431.
- Select Car Brand Select Model (auto-detect is better to detect the vehicle VIN).
- Select and check the following: ECMECT (Engine and ECT), ECM (Engine Control Module)
- Select Special Function Then click Fuel PCV Compensation Value reset.
The sample car model with this feature is the Toyota Rav4.
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