P1425
FordEGI Glow Plug Secondary Failure
This code indicates a detected secondary failure associated with the Ford EGI glow-plug system. Glow plugs help a diesel engine start and run smoothly when cold. The code does not, by itself, identify a failed plug or prove that a particular part needs replacement. Exact system operation and applicability depend on the vehicle’s model, year and engine.
⚠️ Before You Begin (Safety First)
A glow-plug fault can make cold starting difficult or cause rough running after startup. Avoid repeated long cranking, which can strain the starter and battery. If the engine stalls, runs severely rough, or cannot start reliably, do not drive it; arrange diagnosis. Use caution around hot engine parts and high-current electrical connections.
Common Symptoms
- The engine may crank longer or be harder to start when cold if glow-plug assistance is reduced.
- The engine may run roughly shortly after a cold start if combustion is affected.
- Exhaust smoke may be more noticeable during a difficult cold start.
- There may be no obvious symptoms, particularly when the engine is warm.
Common Causes
- A glow plug may not operate as expected.
- A damaged, loose or corroded connection or wire may interrupt the glow-plug system.
- A fault in the system’s power supply, control, or monitoring components may be detected.
- The code may reflect a secondary system fault; related codes and vehicle-specific diagnostics are needed to determine the underlying condition.
Diagnostic Steps
- Note whether starting or running symptoms occur mainly when the engine is cold, and record any other diagnostic codes before clearing them.
- With the engine off and cool, visually inspect accessible glow-plug system wiring and connectors for looseness, corrosion or damage; do not pull on wiring or force connectors.
- Check the battery condition and connections, since weak electrical supply can complicate starting and system diagnosis.
- Do not apply battery power directly to a glow plug or probe unfamiliar control wiring. Have a qualified technician perform electrical tests and confirm the cause using service information for the exact vehicle.
When to Call a Professional
Read all related engine and glow-plug system codes before clearing anything. Use vehicle-specific service information to identify what EGI means for this engine, then inspect connections and wiring and test the glow plugs and their control system using appropriate procedures. A code alone does not distinguish a plug fault from a wiring, power, control or monitoring fault.
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Commonly Asked Questions
Does P1425 prove that a glow plug needs replacement?
No. It identifies a detected EGI glow-plug secondary failure, but does not by itself identify a failed plug. Wiring, connections, power, control or monitoring faults may also need to be checked.
Can I keep driving with this code?
If the engine starts and runs normally, the code alone does not establish an immediate driving hazard. Cold starting may be unreliable. Stop driving if the engine stalls, runs severely rough or cannot be started reliably.
Why might there be no noticeable symptoms?
Glow-plug assistance matters most during cold starting. A warm engine may start and run normally even when a glow-plug system fault is present.
What should be checked before replacing parts?
Check related codes, accessible wiring and connectors, electrical supply, the glow plugs and the system’s control and monitoring functions. The correct tests depend on the vehicle’s model, year and engine.
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