Definition of Code P1394
Code P1394 is a manufacturer-specific code indicating an issue with the crankshaft position (CKP) or camshaft position (CMP) system. Its exact meaning varies by brand but generally relates to:
“Intermittent Crankshaft/Camshaft Position Sensor Signal – Bank 1”
The engine control module (ECM/PCM) has detected an irregular or intermittent signal from one of these essential sensors for engine timing.
Meanings by Manufacturer
For Honda/Acura
- Intermittent desynchronization between CKP and CMP signals
- Engine timing issue
For GM/Chevrolet/Opel
- “Crankshaft System Variation Not Learned”
- Requires specific learning procedure
For Ford
- Intermittent signal from the camshaft position sensor (CMP)
For Hyundai/Kia
- Intermittent discrepancy between CKP and CMP signals
Probable Causes
- Faulty CKP or CMP sensor (internal defect)
- Wiring issues:
- Loose, oxidized, or corroded connectors
- Damaged, cut, or rubbing wires
- Poor ground connection
- Mechanical problems:
- Damaged reluctor wheel (missing or damaged teeth)
- Loose sensor or incorrect clearance
- Metal debris on the sensor
- ECU issue (rare)
Common Symptoms
- 🚗 Intermittent hard starting (especially hot or cold)
- 🔄 Unstable idle or stalling
- ⚡ Random misfires
- 🐌 Sudden power loss
- ⚠️ Check engine light on (may flash during misfires)
- 🔥 Increased fuel consumption
Diagnostic Procedure
1. Visual Inspection (CRUCIAL)
- Locate CKP (crankshaft) and CMP (camshaft) sensors
- Check connectors: disconnect and inspect for corrosion/pins
- Inspect wiring along entire path (rubbing, burns)
- Clean connectors with contact spray if needed
2. Electrical Tests
- Measure sensor resistance (compare to manufacturer specs)
- Check supply voltage (typically 5V or 12V)
- Test continuity of circuits to ECU
- Check ground of sensor and ECU
3. Advanced Analysis (recommended)
- Use an oscilloscope to visualize the signal
- Look for interruptions or signal distortions
- Check CKP/CMP synchronization
4. Mechanical Checks
- Inspect reluctor wheel (if accessible) for missing teeth
- Tighten sensor to specified torque
- Check crankshaft endplay
Solutions and Repairs
- Clean and secure all connectors
- Replace damaged wiring
- Replace faulty sensor (CKP or CMP)
- Perform learning procedure (especially on GM)
- Replace damaged reluctor wheel
- Reset ECU after repair
Affected Models
This code frequently appears on:
- Honda Civic, Accord, CR-V
- GM/Opel with Ecotec engines
- Ford Focus, Fiesta
- Hyundai i30, Tucson
- Kia Ceed, Sportage
Important Tips
- 🔧 The cause is often a simple connector – inspect it carefully first
- 📟 An advanced diagnostic tool (like Autel, Snap-On) is often needed for learning procedures
- 🔁 Since the problem is intermittent, the vehicle may seem to run normally after clearing the code until it recurs
Note: Always consult your vehicle’s specific technical documentation for accurate diagnosis, as the meaning of this code may vary.