OBD Guide

P2B66

Coolant Pump D Control Circuit/Open

P2B66 is an OBD-II diagnostic trouble code meaning: Coolant Pump D Control Circuit/Open. Common causes: open or short circuit in the pump control circuit, pump relay fault. Estimated repair cost: $33–133.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$33–133 (est.)

Symptoms

  • Check Engine Light Is On
  • Engine overheating
  • Long warm-up of the interior in winter
  • Unstable operation of the cooling system
  • Reduced efficiency of the climate system

Causes

  • Open or short circuit in the pump control circuit
  • Pump relay fault
  • Poor contact in connectors
  • Coolant pump failure
  • Problems with the engine control unit

How to Fix

  1. Check the pump fuse and relay
  2. Inspect the wiring harness for damage
  3. Check connections and connector contacts
  4. Test the operation of the coolant pump
  5. Replace the pump if necessary

Related codes

Error P2B66 by Vehicle Brand

FAQ

What does the P2B66 code mean?

P2B66 is an OBD-II diagnostic trouble code that indicates: Coolant Pump D Control Circuit/Open

What causes a P2B66 error code?

The most common causes of P2B66 include: Open or short circuit in the pump control circuit; Pump relay fault; Poor contact in connectors; Coolant pump failure.

How do I fix a P2B66 diagnostic trouble code?

To fix P2B66: Check the pump fuse and relay. Inspect the wiring harness for damage. Check connections and connector contacts. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P2B66?

Limited driving only, diagnose soon

How much does it cost to fix P2B66?

The estimated repair cost for P2B66 is $33–133. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat