P0012 Explained: Understanding Over-Retarded Intake Camshaft Timing

P0012 Explained: Understanding Over-Retarded Intake Camshaft Timing

Diagnostic Trouble Code (DTC) P0012 stands for “Intake (A) Camshaft Position Timing – Over-Retarded (Bank 1).” This code indicates that the engine control module (ECM) has detected that the intake camshaft timing for bank 1 is more retarded than what the ECM has commanded. This condition occurs when the camshaft timing is delayed beyond the acceptable range.

How Serious Is This Issue?

The severity of the P0012 code can vary. In some cases, it may cause minor drivability issues, while in others, it can lead to significant engine performance problems. If left unaddressed, it could potentially cause more severe engine damage.

Is It Safe to Drive with This DTC Code?

Driving with a P0012 code is not recommended. The engine may experience poor performance, stalling, or even fail to start. Additionally, driving with this code can lead to further damage to the engine components, making the repair more costly.

Symptoms and Common Causes


  • Illuminated Check Engine Light
  • Engine struggles to start
  • Poor idling
  • Engine stalling
  • Decreased fuel efficiency
  • Rattling noise from the engine

Common Causes:

  • Low or dirty engine oil
  • Failing camshaft variable timing solenoid
  • Worn timing chain or timing belt
  • Faulty variable valve timing (VVT) actuator
  • Contaminated engine oil obstructing the VVT solenoid screen
  • Inadequate oil flow to the variable camshaft timing system

How Can I Fix It?

Steps to Fix P0012:

  • Check Engine Oil: Ensure the engine oil level is correct and the oil is clean. Replace the oil and filter if necessary.
  • Inspect VVT Solenoid: Check the variable valve timing solenoid for proper operation. Replace if faulty.
  • Check Timing Chain/Belt: Inspect the timing chain or belt for wear and proper alignment. Replace if necessary.
  • Clean or Replace VVT Actuator: Ensure the VVT actuator is not stuck or damaged. Clean or replace it as needed.
  • Inspect Wiring and Connections: Check for any damaged wiring or poor connections related to the camshaft position sensor and VVT system.

Can I Fix This DTC Code Myself?

If you have basic mechanical skills and the necessary tools, you may be able to fix the P0012 code yourself. However, some steps, like checking the timing chain or belt, may require more advanced skills and tools. If you’re not confident in your abilities, it’s best to consult a professional mechanic.

Parts That Might Need Replacement and Repair Costs

Parts That Might Need Replacement:

  • Engine oil and filter
  • Camshaft variable timing solenoid
  • Timing chain or belt
  • VVT actuator
  • Camshaft position sensor

Estimated Costs:

  • Oil and Filter Change: $30 – $70
  • VVT Solenoid: $50 – $150
  • Timing Chain/Belt Replacement: $500 – $1,000
  • VVT Actuator: $200 – $500
  • Camshaft Position Sensor: $100 – $200

Will the Repair Be Expensive?

The cost of repairing a P0012 code can vary widely depending on the underlying cause. Simple fixes like an oil change are inexpensive, while more complex repairs like replacing the timing chain can be costly. On average, expect to spend between $200 and $1,000.

Can I Reset the DTC Code Myself?

You can reset the DTC code using an OBD-II scanner. However, if the underlying issue is not resolved, the code will likely reappear. It’s essential to diagnose and fix the root cause before resetting the code.

Will It Affect Performance or Fuel Efficiency?

Yes, a P0012 code can significantly affect engine performance and fuel efficiency. Symptoms like poor idling, engine stalling, and decreased fuel efficiency are common. Addressing the issue promptly can help restore your vehicle’s performance.

How Can I Prevent It in the Future?

Preventive Measures:

  • Regularly change engine oil and filter as per the manufacturer’s recommendations.
  • Use the correct type of oil specified for your vehicle.
  • Perform routine maintenance checks on the timing chain/belt and VVT system.
  • Address any engine performance issues promptly to prevent further damage.


The P0012 DTC code indicates an issue with the intake camshaft timing being over-retarded, which can lead to various engine performance problems. While some fixes are straightforward, others may require professional assistance. Regular maintenance and prompt attention to any engine issues can help prevent this code from appearing in the future. If you encounter this code, it’s crucial to diagnose and address the root cause to avoid further damage to your vehicle.

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