OBD Guide

P25BB

Regeneration Control Switch Circuit Low

P25BB is an OBD-II diagnostic trouble code meaning: Regeneration Control Switch Circuit Low. Common causes: open or short circuit in wiring harness, regeneration switch malfunction. Estimated repair cost: $17–89.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$17–89 (est.)

Symptoms

  • Check Engine Light Is On
  • Reduced engine power
  • Increased fuel consumption
  • Inability to start forced DPF regeneration
  • DPF error message on the dashboard

Causes

  • Open or short circuit in wiring harness
  • Regeneration switch malfunction
  • Poor contact in wiring connectors
  • Problems with the engine control unit
  • Corrosion of contacts in the control circuit

How to Fix

  1. Check the integrity of the wiring and connectors in the control circuit
  2. Test the regeneration switch for malfunctions
  3. Check control circuit voltage
  4. If necessary, replace the switch or damaged wires
  5. Reset the error code and check the system after repair

Related codes

Error P25BB by Vehicle Brand

FAQ

What does the P25BB code mean?

P25BB is an OBD-II diagnostic trouble code that indicates: Regeneration Control Switch Circuit Low

What causes a P25BB error code?

The most common causes of P25BB include: Open or short circuit in wiring harness; Regeneration switch malfunction; Poor contact in wiring connectors; Problems with the engine control unit.

How do I fix a P25BB diagnostic trouble code?

To fix P25BB: Check the integrity of the wiring and connectors in the control circuit. Test the regeneration switch for malfunctions. Check control circuit voltage. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P25BB?

Limited driving only, diagnose soon

How much does it cost to fix P25BB?

The estimated repair cost for P25BB is $17–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat