OBD Guide

P25B8

Auxiliary Ignition Switch On/Start Position Circuit Low

P25B8 is an OBD-II diagnostic trouble code meaning: Auxiliary Ignition Switch On/Start Position Circuit Low. Common causes: faulty ignition relay, open or short circuit in wiring. Estimated repair cost: $6–33.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$6–33 (est.)

Symptoms

  • Problems starting the engine
  • Incorrect operation of electrical equipment
  • Check Engine Light Is On
  • Intermittent operation of vehicle systems
  • Loss of power when turning the key

Causes

  • Faulty ignition relay
  • Open or short circuit in wiring
  • Problems with the ignition switch
  • Contact corrosion
  • Engine control unit malfunction

How to Fix

  1. Check the condition of the ignition relay
  2. Inspect the wiring for damage
  3. Check the ignition switch contacts
  4. Test the voltage in the circuit
  5. If necessary, replace faulty components

Related codes

Error P25B8 by Vehicle Brand

FAQ

What does the P25B8 code mean?

P25B8 is an OBD-II diagnostic trouble code that indicates: Auxiliary Ignition Switch On/Start Position Circuit Low

What causes a P25B8 error code?

The most common causes of P25B8 include: Faulty ignition relay; Open or short circuit in wiring; Problems with the ignition switch; Contact corrosion.

How do I fix a P25B8 diagnostic trouble code?

To fix P25B8: Check the condition of the ignition relay. Inspect the wiring for damage. Check the ignition switch contacts. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P25B8?

Limited driving only, diagnose soon

How much does it cost to fix P25B8?

The estimated repair cost for P25B8 is $6–33. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat