Technical Description of OBD-II Trouble Code
The circuit controlling the Positive Crankcase Ventilation Heater is experiencing low voltage.
What does that mean?
This is a generic diagnostic trouble code (DTC) that applies to OBD-II vehicles, including BMW, Mini, Jeep, Chrysler, Ford, and others.
The Positive Crankcase Ventilation (PCV) system is designed to remove harmful vapors from the engine and prevent them from being released into the atmosphere. It uses manifold vacuum to draw the vapors from the crankcase into the intake manifold, where they are burned alongside the fuel and air mixture. The PCV valve controls the circulation within the system, making it an effective ventilation and pollution management device for the crankcase.
The PCV system has been standard in all new vehicles since the 1960s, with various types of systems created over the years. However, the main function remains the same. There are two main types of PCV systems: open and closed. Both function similarly, but the closed system has proven to be more effective for air pollution control since its introduction in 1968.
The PCV system includes a heater element that helps remove moisture, a major contaminant in the engine. While the engine generates heat that can burn off most of the moisture, condensation occurs when it cools down. Engine oils contain additives that suspend the water molecules caused by the moisture, but over time, the capacity of these additives is exceeded, leading to water corrosion of the engine’s metal parts.
The Engine Control Module (ECM) monitors and adjusts the positive crankcase ventilation heater control circuit. If the P053B code is active, the ECM has detected a low voltage electrical condition in the PCV heater control circuit.
Example of a PCV valve:
What is the severity of this DTC?
In this case, the severity is medium-high. Dealing with the problem is crucial because a failed PCV system due to sludge buildup and oil leaks can cause damage to the engine. A plugged PCV valve can lead to various other engine problems, including gasket and oil seal failure due to increased pressure.
What are some of the symptoms of the code?
Symptoms of a P053B diagnostic code may include:
What are some of the common causes of the code?
Causes for this P053B positive crankcase ventilation code may include:
What are some P053B diagnostic and troubleshooting steps?
The first step in the troubleshooting process for any malfunction is to research the Technical Service Bulletins (TSB) for known issues with the specific vehicle.
Advanced diagnostic steps are vehicle-specific and may require specialized equipment and knowledge. The following are basic steps, but refer to a vehicle-specific repair guide for detailed instructions.
Basic Step #1
There are several ways to check if the PCV valve is working correctly. Regardless of the method used, the engine should be idling. Here are two methods:
Method 1: Detach the PCV valve from the valve cover with the hose still attached. Place your finger over the open end of the hose. If the valve is functioning properly, you will feel a strong suction sensation. Shake the valve to check for any obstructions. If it rattles, there are no obstructions. If there is no rattling sound, the valve is damaged.
Method 2: Remove the cap from the oil filler hole on the valve corner. Place a stiff piece of paper on top of the opening. If the valve is functioning properly, the paper should be sucked in place against the hole within seconds.
If the valve is not functioning properly, try cleaning it with carburetor cleaner, focusing on areas with significant contamination. Ensure any discoloration and gummy deposits are removed, indicating a thorough cleaning of the valve.
Basic Step #2
Inspect the harness involved in the PCV system’s circuit(s). Oil contamination is a possible cause due to the presence of oil within the system. If oil is leaking on harnesses, wires, and/or connectors, it can cause electrical issues by eating away at wire insulation. Repair any oil contamination to ensure a good electrical connection within the positive crankcase ventilation heater control circuit.
This article is for informational purposes only, and specific technical data and service bulletins for your vehicle should always take precedence.
