Ford P1390 Code: Crankshaft/Camshaft (VCT) Synchronization Problem – Diagnosis and Solutions

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The P1390 code on Ford vehicles (F-150, Escape, Focus, Mustang, etc.) indicates a critical desynchronization between the crankshaft (CKP) and the camshaft (CMP). This fault disrupts the VCT (Variable Camshaft Timing) system, risking severe damage to EcoBoost, Ti-VCT, or Duratec engines.


🚨 Immediate Symptoms

  1. Hard cold starting (metallic rattling).
  2. Sudden loss of power + violent jerking during acceleration.
  3. Flashing check engine light (associated codes: P0016, P0340).
  4. Excessive oil consumption or leaks (related to the VCT system).

🔧 Specific Ford Causes

  1. VCT solenoid failure (clogging, mechanical blockage).
  2. Worn VCT phaser (internal wear on EcoBoost 2.0L/3.5L > 120,000 km).
  3. Stretched timing chain (F-150 5.0L, Mustang GT models).
  4. Faulty CMP/CKP sensor (exposure to oil leaks/scale).
  5. Low oil pressure (failed pump, clogged filter, degraded oil).

🔍 Step-by-Step Diagnosis

  1. Check oil pressure:
    • Minimum required: 12 psi at idle, 35+ psi at 2,000 RPM (Ford 014-0072 Gauge).
  2. Inspect VCT solenoids:
    • Disconnect and measure resistance (5–15 Ω on EcoBoost).
    • Check anti-drainback filters (often clogged).
  3. Test sensors:
    • CKP: AC 0.5–4.5V signal (oscilloscope).
    • CMP: 200–1,000 Ω resistance (Focus 2.0L).
  4. Advanced Ford scan:
    • Use IDS/FDRS to analyze live VCT angles (offset > 4° = fault).

🛠️ Recommended Repairs (With Motorcraft References)

Faulty Component Solution Recommended Ford Parts
VCT Solenoid Replace (clean oil passages) Motorcraft CM-5193 (EcoBoost 2.0L)
VCT Phaser Change in pairs (left/right) Motorcraft CM-5191 (F-150 3.5L)
Timing Chain Replace full kit + tensioner Cloyes Kit 9-0667SB (Mustang 5.0L)
CMP Sensor Replace + seal Motorcraft DU-52 (Focus 1.6L)

⚠️ Critical Warning:
EcoBoost and Duratec Ti-VCT engines are interference engines! A desynchronization can cause piston-to-valve collision. Do not force starting!


💡 Key Post-Repair Procedures

  1. Timing alignment:
    • Specific tools: Crankshaft lock 303-507 + Camshaft lock 303-465 (for EcoBoost).
  2. VCT reset:
    • Perform a phaser relearn via IDS/FDRS (“VCT Learn” procedure).
  3. Oil maintenance:
    • Use 5W-30 Full Synthetic (WSS-M2C946-B1) + Motorcraft filter FL-910S.

📊 Technical Sheet

Parameter Value
OBD2 Code P1390
Definition “Crankshaft/Camshaft Position Sensor Correlation”
Sensitive Models F-150, Escape, Focus, Mustang (2008–2023)
Urgency MAXIMUM (risk of engine destruction)

Comparison of Common Failures by Model

Model Recurring Problem Solution
F-150 EcoBoost 3.5L Noisy VCT phasers when cold Motorcraft phaser kit CM-5191
Focus 1.6L Ecoboost Clogged VCT solenoid (obstructed filter) Replace CM-5193 + clean gallery
Mustang GT 5.0L Stretched chain (dry rattling) Cloyes chain kit 9-0667SB

Exclusive Ford Technical Tips

  1. Avoid generic parts:
    • Non-OEM solenoids cause relapses (recurrent P1390 error).
  2. Software update:
    • On Escape 2013–2016, an ECU recalibration (TSB 16-0114) often resolves the code.
  3. Check coolant:
    • An oil/coolant mix (failed head gasket) clogs VCT phasers.

Conclusion

The P1390 code on Ford points to a critical fault in the VCT system or engine timing. Priority actions:

  1. Urgently check oil pressure and the condition of VCT solenoids.
  2. Replace phasers or chain if necessary with Motorcraft parts.
  3. Perform a VCT relearn via IDS/FDRS.

Do not drive with this code! Have the vehicle towed to a certified Ford technician. Ignoring it can lead to:

  • Destruction of valves (cost: €3,000+),
  • Turbo damage (on EcoBoost).

📌 Note: For post-2018 models, a desynchronization can activate limp mode (power limited to 50%). Always use an IDS scanner for reliable diagnosis.

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