Ford Fault Code P1393

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The Ford P1393 code has a different meaning than at Chevrolet/GM. At Ford, this code generally corresponds to:

Definition

P1393 – Camshaft Position (CMP) Sensor Circuit Range/Performance
This code indicates that the Powertrain Control Module (PCM) has detected an abnormal signal from the Camshaft Position (CMP) sensor.


Possible Causes

  1. Faulty CMP Sensor – The sensor is not providing a correct signal to the PCM.
  2. Wiring or Connector Issues – Damaged wires, short circuits, poor contact.
  3. Timing Problem – Incorrect synchronization between the camshaft and the crankshaft.
  4. Reluctor (Toothed Wheel) Defect – Damaged or worn teeth on the CMP sensor wheel.
  5. PCM Problem – Internal failure of the control module (rare).

Common Symptoms

  • Hard Starting Engine (especially when cold)
  • Misfires or unstable idle
  • Loss of Power and reduced performance
  • Malfunction Indicator Lamp (MIL) illuminated

Diagnosis and Repair

1. Check the CMP Sensor

  • Resistance Test (if applicable, depending on the model).
  • Visual Inspection (cracks, physical damage).
  • Signal Check with an oscilloscope or diagnostic tool.

2. Inspect Wiring and Connectors

  • Check the wires between the CMP sensor and the PCM.
  • Look for short circuits, breaks, or corrosion.

3. Check Engine Timing

  • If the timing belt has jumped or is misaligned, it can affect the CMP signal.

4. Replace the CMP Sensor if Necessary

  • Some Ford models use magnetic or Hall effect CMP sensors.

5. Reset the PCM After Repair

  • Clear the code and check if it returns.

Important Note

On some Ford models (such as the Focus, F-150, Escape), a faulty CMP sensor can also trigger P0340 or P0345 codes.

If the problem persists after replacing the sensor, check:
The sensor’s supply voltage (usually 5V or 12V depending on the model).
The condition of the camshaft’s reluctor (toothed wheel).

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