P0012: Camshaft Timing Out Of Position

What is P0012?

P0012 is an OBD-II Diagnostic Trouble Code (DTC) defined as “Camshaft Position A – Timing Over-Retarded (Bank 1).”

It means that your car’s Engine Control Module (ECM) has detected that the intake camshaft timing for Bank 1 (the engine side that holds the number one cylinder) is more retarded than what the ECM commands it to be. This over-retarded timing can happen during the advancing or retarding phase of the camshaft timing.

A variable valve timing system (VVT system) optimizes fuel consumption and engine performance by regulating when the intake and exhaust cam valves open and close. These valves are driven by the camshaft.

The ECM adjusts the camshaft through the oil control valve (or variable valve timing control solenoid valve). It analyzes the actual intake valve timing using signals from the crankshaft and camshaft position sensor. This is how the ECM verifies the intake camshaft timing.

The P0012 code occurs when the ECM detects that the intake camshaft is stuck in a retarded position or opens too long after the engine’s intake cycle.

Common symptoms

If your vehicle has an over-retarded camshaft timing for Bank 1, you’re likely to come across one or more of the following symptoms:

• The ECM will switch on the Check Engine Light if the camshaft timing cannot be commanded to move. 

Note: Depending on your car’s model, the Check Engine Light may be known as the Service Engine Soon (SES) light or the Malfunction Indicator Lamp (MIL).

• The vehicle will experience misfire codes (P0300-P0308) in one or multiple cylinders.
• You may hear rattling or knocking noises from the car engine. 
• Depending on how retarded the camshaft position is, the engine may function roughly, idle, or frequently stall.
• The engine will consume large amounts of fuel (decreasing fuel economy) as the camshaft isn’t in a normal position.
• The car engine will struggle due to the retarded cam timing, especially during cold starts. 
• Your car will fail emissions tests or smog checks due to reduced fuel efficiency.
• The car will struggle to acquire greater speeds and show poor engine performance because of the failing camshaft position sensor.

Can I still drive?

It’s advisable to stop driving immediately and fix DTC P0012 without delay to avoid internal engine damage. Since Bank 1 of the engine won’t be running at optimum levels, it may put additional pressure on Bank 2.

Further, the problem may diminish your engine’s fuel economy. The engine may show signs of hesitation, lack power, or simply stumble. You’ll also fail the smog test as the check engine light will be on.

So it’s best to diagnose and fix the P0012 trouble code before resuming regular driving. Neglecting the trouble code for too long may cause critical damage to other engine parts, affect the engine performance, and result in costly repairs.

P0012 causes

Internal engine issues like dirty or sludged oil or incorrect camshaft timing may cause the P0012 trouble code. 

Here’s a more detailed list of some of the underlying reasons for error code P0012:

Oil & Oil Control Valve Issues:

• Low levels of engine oil
• Polluted engine oil
• Usage of incompatible engine oil
• Variable camshaft timing (VCT) oil control valve stuck in an open position
• Insufficient oil flow to the VCT piston and phaser

Variable Camshaft Timing & Variable Valve Timing Issues:

• Malfunctioning cam timing
• Damaged variable camshaft timing solenoid (VCT solenoid)
• Faulty camshaft phaser, jammed in the retarded position
• Defective variable valve timing actuator

Timing Chain Issues:

• Worn timing chain or timing belt that has stretched over time
• Failed timing chain guide or tensioner

Diagnosis

Fixing the P0012 error code requires advanced mechanical knowledge, and you should have a certified technician perform the diagnosis for you.

Your mechanic will typically follow these steps to identify the root cause of the P0012 code:

1. Scan For Any Other Engine Code

Before beginning the repair work, they’ll scan your vehicle to verify code P0012 is the only code present. If any other code is present, they’ll address and repair that first.

2. Check Engine Oil Level And Condition

Next, they’ll observe the color and texture of the engine oil. If the oil is black with slimy consistency, the mechanic will remove the oil cap and valve cover to inspect the valve train for sludge.

After removing the valve cover, they can see if any sludge is blocking the oil’s passage to the oil control valves. If yes, they’ll replace the engine oil.

Additionally, if your engine has a low oil level, the mechanic will fill it up adequately. The oil filter will also be appropriately examined. If the oil filter is too old and shows signs of being ineffective, it’ll be replaced. 

3. Inspect The Camshaft Oil Control Valve

If there isn’t any sludge and the engine has the desired oil viscosity, they’ll check and replace (if required) the Bank 1 intake camshaft oil control valve. 

4. Assess The Camshaft Oil Control Valve Solenoid

The mechanic will get the oil control solenoid valve to be on and off — to see if the camshaft timing changes.

They’ll also look for loose connections, damaged wires, etc., in the oil control solenoid valve and camshaft sensor. This process may entail breaking the wiring harness to inspect all related wiring closely.

5. Check The Oil Pressure

Next, they’ll check the engine oil pressure. The test is usually conducted when the problem occurs with an operational engine. 

6. Reset The Code And Retest

Finally, they’ll reset the codes to clear the OBD-II fault codes and retest the vehicle to see if the P0012 code reappears or if the check engine light turns on.

If no further problems are noted and DTC P0012 still exists, the technician will conduct a manufacturer’s particular pinpoint tests for the P0012 code and fix it as needed.

Possible repairs for P0012 & Costs

To resolve the P0012 code, one has to diagnose and analyze the engine control module data to understand what is causing the malfunction in the camshaft’s timing.

Often a simple oil change can fix the problem. Or a filter replacement can do the trick to ensure proper oil flow to the VCT piston and camshaft phaser.

However, if these don’t solve the issue, it’s likely a more severe concern, like a worn timing belt, solenoid failure, or an actuator failure. That’s why it’s crucial to get your automobile checked by a specialist for proper repair and long-lasting solutions.

Ideally, the certified technician will consider performing any of the below-mentioned procedures in an attempt to clear trouble code P0012:

• Changing the oil and filter as per the engine’s specifications
• Repairing or replacing the wiring to the camshaft oil control solenoid
• Replacing the camshaft oil control valve for the Bank 1 intake camshaft
• Replacing the camshaft phaser
• Switching out the timing chain
• Checking electrical connections in the camshaft sensor and oil control solenoid valve
• Replacing the engine assembly

The repair cost will include the cost of the relevant parts and standard labor charges. Here’s what you can expect to pay for different repairs:

• For a simple oil change: $20-$60
• For fixing or replacing the oil control valve or variable valve timing control solenoid: $300-$400
• For substituting engine assembly: $3000-$4000