P0012 Code: Meaning, Symptoms, Causes, Diagnostics, And Fixes

The P0012 OBD2 Code involves a timing problem with the camshaft. The technical name of the problem is Camshaft Position “A” – Timing Over-Retarded (Bank 1). This generic code comes from the engine control module (ECM) when the bank 1 intake camshaft is retarded or impeded in some ways. The problem can happen in one of two moments when the camshaft is timing during the advancing or retarding phases.

P0012 Code Definition

• P0012 Generic: Camshaft Position “A” – Timing Over-Retarded (Bank 1)
• P0012 Toyota: Camshaft Position ‘A’ Timing Over-Retarded Bank 1
• P0012 Ford: Variable Camshaft Timing Over Retarded Bank 1
• P0012 BMW: ‘A’ Camshaft Position Timing Over-Retarded Bank 1
• P0012 Mazda: CMP Timing Over Retard Right Side

What Does P0012 Mean?

P0012 Generic code shows that the intake camshaft timing is more retarded than what the ECM thinks it should be.

The P0012 Ford code can be triggered when the VCT position is in an over-retarded position.

The P0012 BMW code shows something wrong with the intake camshaft that is regulated by VANOS.

The P0012 code in a Mazda activates when the camshaft has a retarded timing. The camshaft is not properly adjusting to the variable valve timing, which lets the car adjust timing to different rates of speed.

In a Toyota, a P0012 code means that the engine timing for the camshaft is either advanced or retarded. The Oil Control Valve regulates the angle of the intake camshaft.

What Are The Symptoms Of P0012 Code?

When the ECM notices that something is happening with the camshaft, it turns on the check engine light. This is the first sign that something is wrong. However, you might notice a few other symptoms as the light shines.

Your vehicle’s engine might have difficulty starting because of the retarded position of the camshaft. As the camshaft is not in the ideal position, you might have reduced fuel efficiency, too. As the camshaft is important to the car running as it should, you might also notice a rougher ride with the engine stalling or hesitating.

What Are The Causes Of P0012?

The causes of P0012 usually involve the camshaft or the oil control valve. One cause could be the camshaft phaser unable to get out of the retarded position. Along with this cause, you might see that the variable camshaft timing oil control valve is open and unable to close. The variable camshaft timing piston and phaser might have issues with oil flow, too.

How Serious Is P0012 Code?

Any issue that causes the engine to run roughly along with stalling or hesitating can be a serious issue. The valve train or engine could have more problems if the P0012 problems are not repaired. Your vehicle could develop more problems because of excessive fuel consumption affecting engine parts. Carbon fouling is another serious issue that can come from not repairing the failed camshaft position. 

How To Diagnose The P0012 Code?

Because car engines differ in makes and models, the exact method varies. After the P0012 code is determined, you should walk through a few steps to determine what the actual problem is. First, look at the wiring connections near the oil-control solenoid valve, and the camshaft and crankshaft sensors, too. If there are problems with the connections, the P0012 code might be triggered.

You should also check if the car has plenty of clean oil with the proper viscosity as recommended by the manufacturer. The recommended oil will be listed in the vehicle’s manual.

You can use the code scanner to find out when the code is triggered and what is happening in the vehicle at that time. Then, reset the codes and see if the ECM sends the code again. If this happens, you should turn the oil control solenoid valve on and off to test the camshaft timing. If nothing happens, it is time to investigate the pinpoint tests and properly repair the car.

What Common Mistakes To Avoid While Diagnosing Code P0012?

There may be a problem with the timing of the camshaft and not a problem with the wiring to the ECM. You can do this by visually checking the wiring connections on the sensors that talk to the ECM. Then, run through the pinpoint steps so you do not misdiagnose the P0012 code. It is best to only make repair if you are certain the problem exists.

What Should I Do To Fix The Code P0012?

There are a few things you can do to fix the P0012 code. The first is to reset the codes and take the vehicle for a drive to determine if it has a rough ride, stalls, or hesitates. It is also helpful to change the oil and filter to the specifications in the vehicle’s owner’s manual.

You can also repair connections and wiring at the camshaft oil control solenoid. You might have to replace the wiring or connections. You might need to replace the camshaft oil control valve at the intake camshaft. After that, look for jumped timing problems at the timing chain. If there is a problem, you should repair it.

You will need a ratchet and socket set to change the oil. You might also need an oil filter wrench and a pan for the oil change, too. A camshaft sensor tester is useful for checking the wiring near the camshaft.

Tips To Avoid P0012 In The Future

Avoiding the P0012 code is partially in your control. Because the camshaft phaser uses oil pressure and oil to control the advance and retard function, you should be sure you are using the right type of oil in your vehicle. If the oil is the wrong viscosity, the camshaft phaser can be affected thus triggering codes and causing engine-running problems.