Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor A)
Code P0016 means the PCM has detected that the crankshaft position sensor (CKP) and camshaft position sensor (CMP) signals are out of sync on Bank 1. The crankshaft and camshaft must be precisely timed together via the timing belt or chain — the PCM compares both sensor signals and sets P0016 when the angular difference between them exceeds a threshold. This can indicate a jumped timing chain, a slipped tone ring, failed sensors, or damaged wiring. P0016 should be treated as a potentially serious engine problem — a skipped timing event can cause engine damage.
What You Might Notice
- Check engine light on
- Engine cranks but will not start, or starts hard
- Rough running with reduced power
- Rattling noise from the front of the engine (timing chain)
- Engine may start and immediately stall
- Multiple additional codes may be stored alongside P0016
Most Common Causes
- 1
Stretched or jumped timing chain or belt
The most serious cause. A worn timing chain that has stretched or jumped a tooth causes the cam and crank signals to fall out of their expected relationship. This requires immediate attention — a jumped chain can cause valve-to-piston contact on interference engines.
- 2
Slipped or damaged crankshaft or camshaft tone ring
The reluctor (tone) rings on the crankshaft or camshaft can slip on their hub or lose a tooth. A damaged or repositioned tone ring sends an incorrect signal to the PCM, appearing as a correlation error even when timing is mechanically correct.
- 3
Failed crankshaft or camshaft position sensor
A sensor that generates a weak, intermittent, or incorrect signal produces a false correlation mismatch. Test both sensors before assuming the timing is mechanically off.
- 4
Damaged wiring or corroded connector on CKP or CMP sensor
Broken wires, chafed harnesses, or corroded connectors on either position sensor can corrupt the signal and create an apparent correlation fault. Inspect both sensor harnesses carefully.
- 5
Worn timing chain tensioner or guides
A failed tensioner allows the chain to go slack, causing intermittent cam/crank phase shifts that set P0016. A rattling noise from the front of the engine at cold start is a strong indicator.
How to Diagnose It
- 1
Check Stretched or jumped timing chain or belt — The most serious cause. A worn timing chain that has stretched or jumped a tooth causes the cam and crank signals to fall out of their expected relationship. This requires immediate attention — a jumped chain can cause valve-to-piston contact on interference engines.
- 2
Check Slipped or damaged crankshaft or camshaft tone ring — The reluctor (tone) rings on the crankshaft or camshaft can slip on their hub or lose a tooth. A damaged or repositioned tone ring sends an incorrect signal to the PCM, appearing as a correlation error even when timing is mechanically correct.
- 3
Check Failed crankshaft or camshaft position sensor — A sensor that generates a weak, intermittent, or incorrect signal produces a false correlation mismatch. Test both sensors before assuming the timing is mechanically off.
- 4
Check Damaged wiring or corroded connector on CKP or CMP sensor — Broken wires, chafed harnesses, or corroded connectors on either position sensor can corrupt the signal and create an apparent correlation fault. Inspect both sensor harnesses carefully.
- 5
Check Worn timing chain tensioner or guides — A failed tensioner allows the chain to go slack, causing intermittent cam/crank phase shifts that set P0016. A rattling noise from the front of the engine at cold start is a strong indicator.
How to Fix It
- 1
Inspect both sensor harnesses and connectors first
Before assuming a mechanical timing fault, visually inspect the CKP and CMP sensor connectors and wiring for corrosion, breaks, or chafing. A wiring fault is cheaper and faster to fix than a timing chain job.
- 2
Test the crankshaft and camshaft position sensors
If available, use a scope to view both sensor patterns. Check for missing teeth or pattern irregularities that indicate a slipped or damaged tone ring. Replace any sensor with a weak or irregular output.
- 3
Inspect the tone rings on both the crankshaft and camshaft
Remove the crankshaft harmonic balancer and cam gear to visually inspect both tone rings for missing teeth, cracks, or rotational slippage on their hub. A slipped ring requires replacement of the affected component.
- 4
Inspect timing chain, tensioner, and guides
Check the timing chain for stretch and the tensioner for collapse. If the chain has jumped a tooth, the timing must be corrected before the engine is run — on interference engines, run the engine only after confirming no valve damage.
- 5
Clear codes and verify with live cam/crank correlation data
After repairs, clear all DTCs and use a scanner to monitor crankshaft and camshaft position correlation live data. Both signals should be in phase within specification across all operating conditions.
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