What Causes a P0012 Code? – An Overview of the Possible Causes

A P0012 code indicates that the camshaft position (CMP) actuator system has a timing over-retarded problem. This means that the intake camshaft is taking too long to reach its desired position in relation to the crankshaft. This can happen for several reasons, including a faulty camshaft actuator, a broken timing chain/belt, worn valvetrain components, or an incorrect valve timing setting. In some cases, it may even be due to a vacuum leak or other engine component failure. The P0012 code should be diagnosed and repaired as soon as possible to avoid further damage to the engine.

What Causes a P0012 Code?

The P0012 code is an indication that the camshaft position (CMP) sensor timing is out of range. This code is triggered when the engine control module (ECM) detects a difference between the actual engine speed and the target engine speed, or when the camshaft position signal is outside of its expected range. The CMP sensor monitors the rotation of the camshaft and sends a signal to the ECM which then adjusts its timing accordingly. If this signal does not match what is expected, then it can cause an issue with engine timing, leading to poor performance and reduced fuel economy.


P0012 is a diagnostic trouble code (DTC) for “Camshaft Position “A” – Timing Over-Retarded”. This code indicates that there is a problem with the camshaft adjustment solenoid valve or its related components. It can also be caused by a fault in the timing chain or belt.

Common Causes

The most common cause of this code being triggered is low oil pressure within the engine. This can be caused by low levels of oil in your vehicle, or by a faulty camshaft adjuster solenoid valve. Other causes include worn out parts such as spark plugs, air filter, oxygen sensors, and timing chain/belt components.


To diagnose this code, you will need to use a scan tool to check for any shorts or open wires in the CMP sensor circuit. You will also need to inspect your timing chain or belt for proper tension and alignment in order to prevent further damage from occurring due to misalignment. Additionally, you should check your oil pressure and levels in order to ensure that everything is performing at its optimal level.


Common symptoms associated with this code include reduced fuel economy, poor acceleration performance, stalling issues due to misfiring, and other issues related to incorrect engine timing such as hard starting or rough idling conditions.

Vehicle Components Involved in P0012 Code

In order for this code to be triggered, there must be an issue with either the camshaft adjuster solenoid valve or with one of its related components such as the timing chain/belt or spark plugs/wires. Depending on how severe the issue is, it may require more complex repairs such as replacing worn-out parts or even replacing entire components if necessary.

Tools Needed To Diagnose And Repair P0012 Code

In order to diagnose and repair this code properly you will need access to a scan tool which can read live data from your vehicle’s computer system as well as access to basic tools such as feeler gauges for checking tension on belts/chains etc.. Additionally it may also be necessary for specialized tools depending on what exactly needs repairing on your vehicle (such as spark plug socket etc.).

Diagnosing The P0012 Code

The first step in diagnosing this issue properly is checking all wiring and connectors connected to both your CMP sensor circuit as well as any related components such as spark plugs/wires etc.. Next you should inspect your timing chain/belt for proper tension using feeler gauges if necessary before inspecting your camshaft adjuster solenoid valve itself which may need replaced if faulty. Lastly you should check all relevant oil pressure levels within your vehicle just in case low levels are causing any issues related directly or indirectly with any other parts involved with this code being triggered.

What Causes a P0012 Code?

A P0012 code is an indication that the camshaft position (CMP) actuator timing for Bank 1 is excessively retarded. This code is typically caused by either an issue with the camshaft adjuster solenoid valve or the timing chain/belt. The camshaft adjuster solenoid valve regulates the oil pressure to the camshaft adjuster, which in turn controls the timing of the camshafts. The timing chain/belt synchronizes the rotation of the crankshaft to that of the camshafts and other components in order to ensure proper operation of valves and pistons.

Repairing a P0012 Code

In order to repair a P0012 code, it is necessary to replace either the camshaft adjuster solenoid valve or the timing chain/belt, depending on which component is causing the issue. If it is determined that there is an issue with the camshaft adjuster solenoid valve, then it should be replaced as soon as possible in order to restore proper functionality. If there are any signs of wear or damage on the timing chain/belt, then it should also be replaced in order to prevent further problems from occurring.

Preventive Measures for Avoiding a P0012 Code

In order to avoid a P0012 code from occurring, there are several preventive measures that can be taken. First and foremost, it is important to regularly change engine oil and filter in order to maintain optimal performance and reduce wear on moving parts. It is also important to inspect and replace the timing chain/belt according to manufacturer’s recommendations in order to ensure proper operation of valves and pistons. Additionally, it is important to clean any dirt or debris from around camshaft position sensor and its associated harness connectors on a regular basis in order to prevent any issues with communication between components.


In conclusion, understanding what causes a P0012 code and taking preventive measures can help reduce downtime due to repairs caused by this type of issue. By regularly changing engine oil and filter, inspecting and replacing timing chains/belts as needed, and cleaning any dirt or debris from around sensors and their associated harness connectors on a regular basis can all help prevent issues from occurring related to this type of fault code.

FAQ & Answers

Q: What is P0012 Code?
A: P0012 is a camshaft position (CMP) timing over-retarded code that is triggered when the engine control module (ECM) detects the camshaft timing for bank 1 intake camshaft is more retarded than what has been commanded.

Q: What are the Common Causes of a P0012 Code?
A: Common causes of a P0012 code include low oil pressure, a faulty camshaft adjuster solenoid valve, and a faulty timing chain/belt.

Q: What Tools are Needed to Diagnose and Repair P0012 Code?
A: A scan tool and feeler gauge are needed to diagnose and repair a P0012 code.

Q: How do I Diagnose the P0012 Code?
A: To diagnose a P0012 code, check the camshaft position sensor circuit for shorts or open wires and inspect the timing chain or belt for proper tension and alignment.

Q: How Can I Preventively Avoid a P0012 Code?
A: To preventively avoid a P0012 code, regularly change engine oil and filter, inspect and replace timing chain/belt as needed, and clean camshaft position sensor and harness connectors frequently.

In conclusion, the P0012 code is generally caused by an issue with the camshaft position actuator solenoid or a timing belt that has jumped a tooth. It can also be caused by low engine oil, worn out parts, or damaged sensors. Therefore, it is important to get your vehicle checked out by a qualified mechanic if you experience this code, as it can cause serious damage to your engine if left unchecked.

Author Profile

Carl Frisch
Carl Frisch
With more than 30 years in the bicycle industry, I have a strong background in bicycle retailing, sales, marketing and customer service. I have a passion for cycling and a dedication to excellence. As a manager, I worked diligently to increase my capabilities and responsibilities, managing up to eleven mechanics (at Palo Alto Bicycles) and later as a working partner in my own store.

As the shop owner of Spoke n’ Word Cycles in Socorro, NM, the success of the mission was my responsibility, which I pursued passionately since we opened in 2003 through the spring of 2011. I am adept at managing owned and loan inventory, preparing weekly & annual inventory statements, and managing staff. The role as managing partner also allowed me tremendous freedom. I used this personal freedom to become more deeply involved in my own advancement as a mechanic, to spearhead local trail building, and advocating for cycling both locally and regionally.

As a mechanic, I have several years doing neutral support, experience as a team mechanic, and experience supporting local rides, races, club events. I consistently strive to ensure that bicycles function flawlessly by foreseeing issues and working with the riders, soigners, coaches and other mechanics. Even with decades of experience as a shop mechanic and team mechanic, and continue to pursue greater involvement in this sport as a US Pro Mechanic, and UCI Pro Mechanic.

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