P0016: Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor A)

What it means

Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor A): the value does not correlate with the related sensor or expected pattern. This relates to engine timing; a fault can cause rough running, a no-start, or timing errors.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

The crankshaft position sensor reports crankshaft rotation, while Bank 1 Sensor A is the camshaft position signal used for timing correlation on the Bank 1 side. The ECM compares these signals with the expected relationship; P0016 sets when the crankshaft and Bank 1 camshaft timing do not align as expected, which can result from a timing-chain or cam-phaser problem.

Common causes

Most likely first.

1. Timing chain stretched
2. Chain tensioner worn or stuck
3. Cam phaser internally failed

Symptoms

• Check engine light on
• Power loss especially in mid-rpm range
• Possible rough idle or stalling
• Increased fuel consumption

How to diagnose it

1. Check freeze-frame data and scan for related camshaft, crankshaft, or variable-timing codes to see when the Bank 1 Sensor A correlation fault occurred.
2. Check engine oil level and condition, since inadequate or unsuitable oil can interfere with cam-phaser operation.
3. Inspect the Bank 1 camshaft and crankshaft sensor connectors and wiring for damage, loose contacts, or oil contamination.
4. Compare live camshaft and crankshaft timing data for Bank 1 Sensor A with the manufacturer's expected pattern and check whether the signal changes with engine speed.
5. If sensor signals and wiring are sound, inspect mechanical timing and the Bank 1 chain tensioner and cam phaser using the vehicle-specific procedure.

Common fixes

• Correct low or unsuitable engine oil and address any oil supply problem affecting cam timing.
• Repair damaged wiring or connections at the Bank 1 camshaft or crankshaft sensor circuits.
• Replace a sensor only if testing shows its signal is faulty.
• Repair or replace a worn timing chain or tensioner if mechanical timing checks confirm excess slack.
• Repair or replace the Bank 1 cam phaser if testing confirms it is not controlling timing correctly.

Can I keep driving?

Avoid hard acceleration and have the timing fault diagnosed promptly; rough running, stalling, or loss of power can make driving unpredictable. If the engine runs very roughly, stalls, or makes unusual timing-chain noise, stop driving because a timing failure can cause severe engine damage.