P0018: Crankshaft Position - Camshaft Position Correlation (Bank 2 Sensor A)

What it means

Crankshaft Position - Camshaft Position Correlation (Bank 2 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 sensor reports engine rotation, while the bank 2 sensor A camshaft signal tracks the corresponding camshaft, usually the intake cam. The control module compares these signals to check their timing relationship. P0018 sets when the bank 2 crankshaft and sensor A camshaft signals do not match the expected correlation, which can point to a stretched timing chain or a bank 2 intake cam phaser fault.

Common causes

Most likely first.

1. Timing chain stretched (bank 2)
2. Bank 2 cam phaser 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. Save freeze-frame data and check for related crankshaft or camshaft sensor codes, which may help distinguish a signal problem from incorrect timing.
2. Review live crankshaft and bank 2 sensor A camshaft data during cranking and running to check whether the cam signal is missing, erratic, or consistently out of time.
3. Inspect the bank 2 sensor A connector and wiring and look for accessible signs of timing-component wear or damage.
4. Test the crankshaft and bank 2 sensor A signals and circuits according to the wiring diagram and manufacturer's procedures.
5. If the signals and circuits test correctly, verify mechanical timing and inspect the timing chain and bank 2 intake cam phaser.

Common fixes

• Repair damaged wiring or a poor connection at the bank 2 sensor A camshaft circuit.
• Replace a crankshaft or bank 2 sensor A camshaft sensor only if testing confirms it is faulty.
• Correct mechanical timing if it is misaligned.
• Replace a stretched timing chain or faulty bank 2 intake cam phaser confirmed by inspection.

Can I keep driving?

Avoid unnecessary driving because incorrect timing can cause rough running, stalling, or a no-start, and continued operation may worsen engine damage. Stop if it runs roughly, makes unusual timing noise, or loses substantial power.