P1375

Ford

Ignition Coil - Cylinder 5 - Early Activation Fault

Definition source: Manufacturer reference catalog
Definition verification: Not independently verified for display.
Time: Varies by diagnosis and vehicle | Diagnostic difficulty: Medium
Medium Severity

The engine control system detected that the ignition coil for cylinder 5 activated earlier than expected. The coil produces the spark that ignites the cylinder’s air-fuel mixture; an early-activation fault can disrupt combustion and cause rough running or a misfire. The code identifies a detected condition, not proof that the coil itself has failed. Exact applicability and test procedures depend on the vehicle’s model, year, and engine.

Report an error with this code

⚠️ Before You Begin (Safety First)

If the engine runs severely rough, loses power, or the check-engine light flashes, stop driving when safe and arrange diagnosis. Continued driving with an active misfire can damage the catalytic converter. Avoid working around moving or hot engine parts.

Common Symptoms

  • The check-engine light may be on, even if the engine seems to run normally.
  • A rough idle or engine misfire may occur if the early activation disrupts combustion on cylinder 5.
  • Hesitation or reduced power may occur if the engine is not firing consistently.
  • There may be no noticeable symptoms if the condition is intermittent or does not significantly affect combustion.

Common Causes

  • The cylinder 5 ignition coil may activate earlier than expected because of an internal coil fault.
  • Damaged wiring, a poor connection, or a short in the coil control circuit may affect the activation signal.
  • A fault in the control circuitry may produce an incorrect coil activation signal; this requires testing before any control module is suspected.
  • An intermittent connection or wiring fault may make the condition come and go.

Diagnostic Steps

  1. Record the code and any other stored codes before clearing anything; related codes or scan data can help narrow the diagnosis.
  2. With the engine off and cool, visually inspect the cylinder 5 coil connector and accessible wiring for looseness, damage, or contamination.
  3. Check that the connector is seated and that accessible wiring is not rubbing against sharp edges or hot components; do not probe terminals unless you have the correct vehicle-specific procedure and equipment.
  4. If the engine is running poorly or the check-engine light is flashing, avoid further driving and arrange professional diagnosis.
  5. Use model-, year-, and engine-specific service information for electrical tests or coil removal; do not assume a coil swap or replacement will confirm the cause.

When to Call a Professional

Confirm the code and review available scan data before replacing parts. Inspect the cylinder 5 coil connector and wiring, then test the coil control circuit and related signals using the vehicle-specific service information. Compare results with other cylinders where appropriate. Consider the engine control module only after the coil, wiring, connections, and circuit behavior have been checked.

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Commonly Asked Questions

Does P1375 prove that the cylinder 5 ignition coil needs replacement?

No. It reports an early-activation condition associated with that coil. The coil, its wiring and connection, and the control circuit need to be checked before deciding what to replace.

Can I keep driving with this code?

If the engine runs smoothly and the check-engine light is steady, arrange diagnosis soon and watch for changes. Stop driving when safe if the light flashes, the engine misfires severely, or power drops significantly.

Why might there be no symptoms?

The fault may be intermittent or may not cause a noticeable change in engine operation. A lack of symptoms does not identify the underlying cause or rule out a circuit problem.

What should be checked before replacing the coil?

Check the stored codes and available scan data, inspect the coil connector and wiring, and test the coil control circuit using procedures for the exact model, year, and engine.

Browse Available Code Guides

Previous and next available guides in database record order, across makes. Adjacent entries may share a code number and do not necessarily describe related faults.