P033F: Crankshaft/Camshaft Loss Of Synchronization

What it means

The PCM has lost crank-to-cam synchronization — the relative phase between crankshaft and camshaft no longer matches the calibrated reference. Causes include a stretched or jumped timing chain, broken cam timing tooth, or sensor signal corruption.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test
• The engine or gearbox may go into limp mode

How it works

The engine control module compares crankshaft position with camshaft position to keep fuel injection and valve timing synchronized. This code means their expected timing relationship has been lost, which can result from a timing chain that has stretched or jumped, a damaged timing reference, or corrupted crank or cam signals.

Common causes

Most likely first.

1. Timing chain stretched or jumped
2. Crank or cam sensor signal corrupted

Symptoms

• Check-engine light
• Hard starting or no start
• Rough running
• Reduced engine power

How to diagnose it

1. Record freeze-frame data and check for related crankshaft or camshaft sensor codes before clearing anything, since they can help distinguish a signal fault from a timing fault.
2. Check live crank and cam synchronization data during cranking and running, if available, and note whether synchronization drops out.
3. Inspect crankshaft and camshaft sensor connectors and wiring for damage, poor contact, or contamination that could corrupt either signal.
4. Test both position-sensor signals and their circuits using the manufacturer's procedure to rule out an electrical cause.
5. If the signals and circuits test correctly, check mechanical timing and timing-chain condition using the manufacturer's procedure before further running.

Common fixes

• Repair a damaged crankshaft or camshaft sensor connector or wire.
• Replace a crankshaft or camshaft position sensor that fails the manufacturer's tests.
• Repair or replace a stretched or jumped timing chain and correct mechanical timing.
• Repair a damaged cam timing reference if confirmed.

Can I keep driving?

Avoid driving; the engine may stall or fail to start, and incorrect mechanical timing can lead to further engine damage. If it runs roughly or has difficulty starting, arrange recovery rather than continuing to drive.