P0016 Fault Code: Camshaft / Crankshaft Correlation (Bank 1)

Meaning and definition

VAG records this code as 16400/P0016/000022, an incorrect correlation between the Camshaft Position Sensor (G40) and the Engine Speed Sensor (G28) on bank 1. The crankshaft and camshaft are linked by the timing chain or belt and must turn in a fixed relationship. The ECU reads the position of each through its sensor, and when the two no longer match within tolerance it stores P0016.

Because the code is about the relationship between the two shafts rather than one part, it is a strong hint that the mechanical timing has moved, most often through chain stretch on VAG petrol engines. It can occasionally be a sensor or wiring issue, but the timing components are always the first thing to rule out.

How the ECU detects the code

The ECU compares the signal from the camshaft sensor against the crankshaft signal many times a second. If the cam is consistently early or late relative to the crank by more than the allowed amount, the ECU flags the correlation as incorrect, stores P0016 and turns on the engine warning light. A larger deviation will often trigger rough running or limp mode as well.

Which VAG engines are most affected

P0016 is most closely associated with the EA888 2.0 TSI and TFSI engines and the smaller 1.4 and 1.8 TSI units across Volkswagen specialists and Audi specialists models, as well as SEAT and Skoda, where timing chain stretch is a well documented weakness. Belt-driven engines can also set it after a skipped tooth or a failed camshaft adjuster. It often appears alongside camshaft sensor codes such as the P0340 camshaft position sensor fault.

Warning light and starting problems

The engine warning light is usually the first sign, often with hard or slow starting as the ECU works to line the timing up. In more advanced cases the car may be reluctant to start at all, because the cam and crank are far enough out that the engine struggles to fire cleanly.

Rough running, misfire and power loss

With the timing out of step the engine can run rough, misfire and feel down on power, and it may drop into limp mode to protect itself. Fuel economy can suffer too. These symptoms tend to get worse as the underlying timing fault develops.

Timing chain rattle

On the chain-driven VAG petrol engines, a rattle from the timing chain area, especially for a few seconds on a cold start, is an important warning sign that often goes hand in hand with P0016. It points to a worn chain or tensioner and should be checked quickly, because it can develop into serious damage.

Timing chain stretch and worn tensioners

On the EA888 engines the leading cause is a stretched timing chain or a failed chain tensioner, which lets the camshaft slip slightly relative to the crankshaft. This is a known weak point on these engines and is the first thing we look at when P0016 appears with a chain rattle.

Camshaft adjuster and oil-related faults

The camshaft adjuster and its control solenoid, sometimes called the spool valve, vary the cam timing in normal use, and a fault here can throw the correlation out. These adjusters rely on clean oil at the right pressure, so low or dirty oil and missed services can bring the problem on or make it worse.

Sensors, wiring and belt faults

Less commonly, a faulty camshaft or crankshaft sensor, damaged wiring, or on belt-driven engines a timing belt that has jumped a tooth can produce P0016. A proper diagnosis separates these from genuine chain wear so the right repair is carried out.

Reading the code and timing data

We start by reading the code and the live timing data with dealer level equipment, which shows the actual deviation between the camshaft and crankshaft. This tells us how far the timing has moved and is the quickest way to judge whether we are dealing with a sensor issue or genuine mechanical wear. It is part of our car diagnostics in Worthing.

Inspecting the chain, tensioner and adjuster

If the data points to mechanical wear, we inspect the timing chain, tensioner, guides and camshaft adjuster. On these engines it is common to find a stretched chain or a tensioner that is no longer holding correctly. Confirming the mechanical condition stops us replacing sensors that were never the cause.

Checking sensors and oil condition

Where the timing looks correct, we test the camshaft and crankshaft sensors and their wiring, and check the oil condition and level, since the cam adjuster depends on clean oil. This confirms whether the fault is electrical or down to oil supply before any parts are changed.

Replacing the timing chain or tensioner

Where the chain has stretched or the tensioner has worn, the fix is to fit a new timing chain kit and reset the timing accurately. This is a substantial job on these engines, but it is the correct repair when chain wear is the cause and it removes the risk of the chain jumping. Our car repairs team carries this out once the diagnosis is confirmed.

Renewing the adjuster, solenoid or sensors

If the cause is the camshaft adjuster, its solenoid or a faulty sensor, the affected part is replaced and the timing rechecked. Where dirty oil has contributed, an oil and filter change is part of putting it right so the new parts are not starved of clean oil.

Verifying the timing and clearing the code

After any repair we verify the camshaft to crankshaft timing, clear the code and road test to confirm the correlation is correct and the warning light stays off. Keeping to regular servicing with the correct oil afterwards helps protect the new timing components.

Regular oil changes and servicing

The timing chain and cam adjusters on these engines depend on clean oil at the right level and pressure. Keeping to the service schedule, using the correct specification oil, and not stretching oil changes all help the chain and tensioner last and reduce the chance of P0016 returning.

Acting on early warning signs

A brief chain rattle on cold start is the classic early warning. Acting on it quickly, before the chain stretches far enough to set a code or jump, can mean a far smaller repair and avoids catastrophic engine damage. For the full set of related codes, see our full VAG fault-code library and the VW and Audi error-code resource.