P1425 Code: Meaning, Symptoms, Causes & Fix

Overview

P1425 is triggered when monitoring logic identifies an issue with EGI Glow Plug Secondary Failure affecting powertrain controls.

Symptoms

check engine light
rough operation in certain conditions
reduced performance

Common causes

Sensor output out of expected lower range affecting egi glow plug secondary failure
Signal pulled low by short-to-ground
Connector pin damage/corrosion or harness stress near related components

How to diagnose P1425

Confirm P1425 and capture freeze-frame data with a professional scan tool.
Inspect wiring, connectors, and grounds related to egi glow plug secondary failure for obvious defects.
Compare live data against expected lower threshold and verify ground/reference circuits.
Check for related DTCs to identify the root-cause chain before replacing parts.
After repair, clear codes and confirm readiness monitors complete without recurrence.

Severity of code P1425

Moderate: This code is moderate severity: the vehicle may still operate, but fault progression can increase repair cost over time.

Can you drive with P1425?

Most vehicles can be driven short-term with P1425, but postpone heavy load/highway driving until repaired.

If the warning lamp is flashing or drivability/safety is affected, avoid driving and diagnose immediately.

How to fix it (step-by-step)

Repair obvious wiring/connector faults first to prevent repeat parts replacement.
Address the root fault mode (low) in the egi glow plug secondary failure circuit/system.
Apply the required relearn/adaptation procedure if specified by service information.
Road-test and verify P1425 remains cleared under the conditions that originally set the code.

Fix options

Repair connector resistance issues.
Verify ground path and signal integrity.
Clear DTCs and verify with live data and completed drive cycle.

Typical repair cost

$200-$900

Common mistakes when diagnosing P1425

Replacing parts without verifying voltage, ground, and signal integrity first.
Ignoring related stored/pending codes that indicate upstream faults.
Skipping post-repair verification drive cycle and readiness checks.

P1425 in common vehicles

P1425 appears across makes such as Ford, Toyota, Honda, Chevrolet. Failure patterns differ by platform: wiring routes, software calibration, and component supplier revisions can change root cause.

Frequently asked questions

What causes P1425?

P1425 is commonly set by low faults affecting egi glow plug secondary failure.

How much does it cost to fix P1425?

For P1425, repair costs are typically $200-$900 depending on exact root cause, labor rates, and part quality.

Can I clear P1425 without repair?

You can clear P1425 temporarily, but the code usually returns until the underlying fault is corrected.