P0344 — Camshaft Position Sensor A Circuit Intermittent — 7.3 Power Stroke
Diagnostic reference for 7.3L Power Stroke (1999–2003) F-250/F-350/F-450/F-550 Super Duty and Excursion. The CMP sensor on the front cover is the only…
What it means
The PCM is seeing an erratic or intermittent camshaft position sensor signal and is losing reliable timing information. On the 7.3L Power Stroke the CMP sensor on the front cover is the sole engine-speed/position input, so an intermittent signal can lead to stall, hard start or no-start.12
Most likely causes
- Camshaft position sensor intermittent or failing — The CMP sensor itself is a known intermittent-failure item on 7.3L trucks and can cause stalling. NHTSA recall notes the sensor may function intermittently and possibly result in engine stall.2
- CMP sensor connector/wiring chafing or corrosion — Intermittent circuit behavior is often wiring/connector related. Generic definition for P0344 is erratic/intermittent camshaft position sensor signal causing loss of reliable timing.1
- Front-cover area oil/coolant contamination of CMP connector — External contamination can cause intermittent electrical contact at the sensor connector, producing the P0344 intermittent circuit condition.1
How to diagnose
- Verify code P0344 is present and check freeze-frame for engine conditions at set.
- Inspect CMP sensor on front cover and its harness for oil/coolant contamination, chafing, loose terminals, and proper routing.
- Check CMP sensor connector for corrosion and secure lock; inspect wiring back toward PCM for damage.
- Monitor CMP signal PID with scan tool while wiggling harness and during a test drive to confirm intermittency.
- If signal drops out with harness movement, repair wiring/connector; if signal is erratic at the sensor, replace CMP sensor.
- Clear codes, road test, and confirm no recurrence of P0344 or related P0341.
Parts and tools you may need
- Digital multimeter
- Scan tool with live data/PIDs
- Basic hand tools for sensor access
Tools you’ll need
- OBD-II scan tool — Reads P0344 and CMP PID to confirm the intermittent cam signal and capture freeze-frame conditions.
- digital multimeter — Checks CMP sensor supply, ground, and signal voltage for opens/shorts and verifies wiring integrity during wiggle tests.
- inspection mirror — Lets you see the front-cover CMP sensor and its harness routing in the tight 7.3L engine bay for chafing or contamination.
Rough cost and difficulty
| Likely repair | Parts | Shop labor | Who usually does it |
|---|---|---|---|
| Wiring or connector repair | $10–$100 | 1–4 hrs | DIY with tools and a manual |
| Crankshaft or camshaft position sensor | $40–$200 | 0.5–2 hrs | DIY with tools and a manual |
Typical US independent-shop figures; labor runs about $120–$180 per hour (dealers charge more). Confirm the diagnosis before buying parts.
When to see a pro
If stalling occurs in traffic or the engine will not restart, have the vehicle inspected promptly. The CMP is the only engine-speed/position input on this engine; intermittent loss can cause sudden stall. Do not attempt high-pressure oil system service. The 7.3L uses HEUI injection with high-pressure oil; avoid contact with pressurized oil lines.
Check for recalls
Recalls are tied to your truck’s VIN, so check yours directly: enter the VIN at NHTSA’s recall lookup. Open safety recalls are repaired free at a dealer.
Sources
Repair videos: P0344 on the 7.3 Power Stroke
Third-party videos, not ours — picked for this engine. Confirm anything against the factory service information for your truck.
Spotted an error, or something missing? Tell us
Run a 7.3 Power Stroke? This goes straight to the editor — it is not published.