P0346 on Ford: How to Diagnose & Fix
Camshaft Position Sensor A Circuit Range/Performance (Bank 2)
1 Ford model · 1 documented issue · 1 critical · $1,800-$4,500 repair
P0346 on Ford by model: symptoms, diagnosis and fix
The 5.4L 3-valve (3V) Triton V8 in 2004-2014 Ford Expedition is notorious for cam phaser failures and timing chain stretch, representing one of the most common and expensive repairs on these trucks. The VCT (Variable Camshaft Timing) system uses oil pressure to actuate the cam phasers - when phasers wear out or chains stretch, the engine sets multiple camshaft correlation codes and rattles on startup. The factory oil pump also wears out at similar intervals, compounding the problem. Running low on oil or using the wrong viscosity dramatically accelerates failure. Left unrepaired, a failed phaser can cause a chain to jump timing, resulting in bent valves and catastrophic engine damage. Repair typically requires complete timing system replacement including both cam phasers, all four timing chains, guides, and tensioners - a 12-16 hour job.
Common Symptoms
- Loud rattling/knocking from engine on cold start (top-end rattle)
- Check engine light with codes P0340, P0341, P0344, P0345, P0346, P0349 (cam sensor/phaser codes)
- Codes P0016, P0017, P0018, P0019 (camshaft-crankshaft timing correlation)
- Rough idle, especially when cold
- Engine surging at idle
- Loss of power and poor fuel economy
- Rattle that worsens on acceleration at low RPM
- Multiple misfire codes accompanying timing codes
How to Fix
Complete timing system overhaul: replace both VCT cam phasers, timing chains (primary and secondary), all chain guides, and tensioners as a complete kit. Motorcraft timing chain and phaser kit (TKIT-2004A-MGA or dealer equivalent) is recommended. Also replace the oil pump if over 80,000 miles - worn pump cannot supply adequate oil pressure for VCT system. Use 5W-20 full synthetic oil only. Change oil every 5,000 miles maximum. Labor: 12-16 hours on Expedition due to 4WD and engine mounts.
Sources for this issue (1)
P0346 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0346 mean on a Ford?
P0346 stands for "Camshaft Position Sensor A Circuit Range/Performance (Bank 2)." The camshaft position (CMP) sensor 'A' signal on bank 2 is present but out of range or not correlating with the crankshaft (range/performance). Often from timing-chain stretch on bank 2, a damaged reluctor, or air-gap/wiring noise. On Ford it is documented across 1 model: Expedition.
What are the most common causes of P0346?
The most common causes of P0346 are: Stretched/worn timing chain on bank 2, Damaged cam reluctor/timing wheel, Degrading bank 2 CMP sensor, Air-gap or loose sensor, Intermittent wiring/electrical interference. The specific cause varies by vehicle.
How much does it cost to fix P0346 on a Ford?
Published repair estimates on Ford range from $1,800 to $4,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0346 on a different make?
View P0346 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.