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.
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:
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).
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.
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:
Variable Camshaft Timing & Variable Valve Timing Issues:
Timing Chain Issues:
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:
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.
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.
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.
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.
Next, they’ll check the engine oil pressure. The test is usually conducted when the problem occurs with an operational engine.
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.
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:
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:
Select your vehicles year, make, and model and the repair service you need.
Get a free quote, book an appointment, and speak to a specialist – all online!
Pick a time that works best for you and our mobile mechanics will bring the shop to you.
Not sure? Let us diagnose
1-Year | 12,000-Mile Warranty