What are the causes of the P0016 fault code?

This blog will answer the following questions: What are the causes of the fault code P0016? What is the location of the camshaft position sensor? What are the symptoms of the P0016 fault code? 

What are the causes of the P0016 fault code?

The causes of the fault code P0016 are given below, fault code P0016 is stored in the engine control unit when the signal from the camshaft position sensor bank 1 is implausible.

  • Faulty camshaft position sensor

The camshaft position sensor is very similar to the crankshaft position sensor. It is a hall effect type sensor and the sensor probe detects the position of the camshaft with the help of a sensor ring or a pulse ring.

The engine control unit is constantly monitoring the position of the camshaft with respect to the position of the crankshaft. The signal from both the sensors is responsible for determining the start of the fuel injection and the ignition angle of the engine.

A Faulty camshaft sensor can send the incorrect position of the camshaft to the engine control unit if there is an internal fault in the sensor or an incorrect sensor is installed. The camshaft position sensor can be magnetic or inductive. 

Therefore, if the electrical lines between the engine control unit and the camshaft position sensor are okay and the part number of the installed camshaft position sensor is correct. The fault is present due to a faulty camshaft position sensor and it must be replaced to rectify the concern. 

  • Incorrect engine timing

The intake and exhaust camshafts are connected to the crankshaft by a timing chain or a timing belt. Both the camshafts are installed in a basic position with respect to the crankshaft when the engine is assembled.

This basic position of camshafts differs from engine to engine but the first firing cylinder is always kept at the ignition top dead center or TDC. due to elongation of the timing chain or a damaged timing belt, the basic position of the camshaft becomes incorrect.

The camshaft position sensor is only detecting the current position of the camshaft. Therefore it is important to check the basic position of the camshaft if the fault is still present after replacing the camshaft position sensor.

The elongated timing chain or the damaged timing belt is replaced and the camshafts are set at the basic position again to successfully rectify the problem.

  • Faulty camshaft adjuster

Camshaft adjusters are responsible for variable valve timing. Car manufacturers usually use variable valve timing in the gasoline engine but some diesel engines are still available in the market with variable valve timing.

The camshaft adjusters consist of a sprocket for the timing chain; there are oil galleries in the adjuster which are filled with engine oil when the center valve opens. The camshaft can move independently in front of the sprocket based on the oil pressure present in the camshaft adjusters.

Therefore, if the springs in the camshaft adjusters that return the camshafts to the basic position are weak or faulty, the camshafts are in the incorrect position when the engine is turned off.

The engine control unit only adjusts the camshafts once the engine is started and the engine oil reaches the camshaft adjusters. The old adjusters cannot be repaired, they are replaced by removing the cylinder head cover and the center valves are also renewed at the time of replacement.

  • Faulty camshaft solenoid

The engine control unit actuates the camshaft solenoid located on the cylinder head front plate. The solenoid opens the central valve of the camshaft adjuster to vary the timing of the engine. A faulty solenoid will not adjust the camshaft and the camshaft will be in an incorrect position despite the actuation signal from the engine control unit.

The solenoids are easy to replace as the location is in front of the engine. No programming is required after replacing the camshaft solenoid. Both the intake and the exhaust camshafts use separate solenoids but the part number is the same.

Therefore, it is possible to temporarily interchange the solenoids and check if the fault code switches to the other side.

What is the location of the camshaft position sensor of bank 1?

The location of the camshaft position sensor of back 1 is on top of the cylinder head cover. Bank 1 refers to the first bank of cylinders, all 4 cylinders in an inline 4-cylinder engine are in bank 1.

The location is the same for V6 and V8 engines but the number of camshaft hall sensors is obviously more as there are more than two camshafts to monitor. Usually, diesel engines have only one camshaft position sensor for both the intake as well as exhaust camshafts.

In diesel engines, there is no variable valve timing and the intake, as well as exhaust camshafts, are directly meshed with each other. Petrol engines on the other hand need separate camshaft sensors for exhaust as well as intake camshafts.

The engine control unit of both the petrol as well as diesel engine can operate with the signal from the camshaft position sensor if the crankshaft position sensor or CKP is not working.

What are the symptoms of the P0016 fault code?

The symptoms of the P0016 fault code are given below:

  • Check engine light will be active as the fault code P0016 is present in the fault code memory of the engine control unit. The fault can be erased by any diagnosis scanner but it will occur unless the cause is rectified.
  • The engine will take a long crank to start, especially during the first cold start. The engine oil gets collected in the oil sump and it takes a few seconds for the oil to reach the camshaft adjusters. The camshafts are not in a basic position and the adjuster is faulty.
  • Abnormal noise can come from the front of the engine when it is starting for the first time after a few hours. The noise comes from the camshaft adjusters but as soon as the oil pressure is reached the engine can operate at normal idle speed.
  • As the engine is long cranking, the starter motor takes more power from the main battery. Therefore, if the fault code P0016 is present, a dead or discharged battery is a common symptom.

There is no power loss unless the timing of the engine is completely incorrect. The engines with timing belts have no abnormal noise as the camshafts are not connected to the crankshaft with a metal chain.


This blog explained the causes of the P0016 fault code. The nature of the fault code is serious as the engine timing is not okay. If the fault is not rectified after replacing the camshaft position sensor then the repairs are expensive as camshaft adjusters and complete camshafts may need replacement to rectify the concern.

 How to fix the P0016 fault code?