Diagnose and fix trouble code P0012
A P0012 trouble code is part of a family of trouble codes that can be set if there’s a problem with the engine’s variable valve timing (VVT) system. The P0012 code is a generic OBDII code defined as: Intake Camshaft Position Timing – Over-Advanced (Bank 1). Bank 1 is the bank containing cylinder #1. The following trouble codes also relate to the VVT system:
P0010 Intake Camshaft Position Actuator Circuit / Open (Bank 1)
P0011 Intake Camshaft Position Timing – Over-Advanced (Bank 1)
P0012 Intake Camshaft Position Timing – Over-Retarded (Bank 1)
P0013 Exhaust Camshaft Position Actuator Circuit / Open (Bank 1)
P0014 Exhaust Camshaft Position Timing – Over-Advanced (Bank 1)
P0015 Exhaust Camshaft Position Timing – Over-Retarded (Bank 1)
What causes P0012?
VVT systems rely on the proper oil viscosity, proper oil level, proper oil pressure, and a good oil control valve, also called a phaser. The computer determines proper camshaft angle and orders a change to either advance or retard the camshaft. At that point the oil control valve or phaser to pulse oil pressure to the VVT mechanism to rotate perform the timing change.
Low oil level can cause a P0012 trouble code
Checking oil level should be the first thing you do if you find a P0012 trouble code. The VVT system must
have constant flow of oil at the right pressure to operate the system. If you find a low oil level, top it off, clear the code and drive the vehicle. If the code doesn’t come back, you’ve found the source of the problem
Sludge buildup can cause a P0012 trouble code
Sludge causes a blockage in the oil pickup tube which then reduces
oil flow to the engine. Sludge is caused by running the engine at low oil levels, neglecting oil changes or going too far on an oil change, poor PCV operation or using a poor quality oil. Change the oil, clear the code and drive the vehicle.
The wrong oil viscosity can cause a P0012 trouble code
The computer assumes you’ve used the recommended oil viscosity. Based on that viscosity, the computer knows how often to pulse the oil control valve to achieve camshaft movement. If you use a different viscosity oil you can cause a P0012 trouble code. Change the oil and filter using the recommended viscosity, clear the code and drive the vehicle. If the code doesn’t return, you’ve found the root cause.
The wrong oil filter can cause a P0012 trouble code
Some engines are especially particular about the oil filter used. Some aftermarket oil filters reduce oil flow and reduce oil pressure to the point where it causes a substantial enough drop in pressure to result in improper VVT operation which then sets a P0012 trouble code.
If your engine was working properly until you did an oil and filter change and the code set shortly after that, suspect the oil filter.
A bad or clogged oil control valve or phaser can cause a P0012 trouble code
Running too long on an oil change can cause sludge buildup
in the filter screen of the oil control valve and that can cause it to malfunction and set a trouble code. If you’ve performed the fixes listed above, check the inlet screen on the oil control valve or phaser.
©, 2019 Rick MuscoplatPosted on by Rick Muscoplat