OBD Guide

P26AC

Engine Coolant Bypass Valve B Control Circuit/Open

P26AC is an OBD-II diagnostic trouble code meaning: Engine Coolant Bypass Valve B Control Circuit/Open. Common causes: broken wires in the control circuit, coolant bypass valve malfunction. Estimated repair cost: $17–56.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$17–56 (est.)

Symptoms

  • Engine overheating
  • The engine takes a long time to warm up
  • Unstable engine temperature
  • Check Engine Light Is On
  • Decrease in interior heater efficiency

Causes

  • Broken wires in the control circuit
  • Coolant bypass valve malfunction
  • Corrosion or poor contact in connectors
  • Problems with the control relay
  • Engine control unit (ECU) malfunction

How to Fix

  1. Check the integrity of wires and connections in the control circuit
  2. Test valve resistance and operation
  3. Clean connector contacts from corrosion
  4. Check the operation of the control relay
  5. Replace the coolant bypass valve if necessary.

Related codes

Error P26AC by Vehicle Brand

FAQ

What does the P26AC code mean?

P26AC is an OBD-II diagnostic trouble code that indicates: Engine Coolant Bypass Valve B Control Circuit/Open

What causes a P26AC error code?

The most common causes of P26AC include: Broken wires in the control circuit; Coolant bypass valve malfunction; Corrosion or poor contact in connectors; Problems with the control relay.

How do I fix a P26AC diagnostic trouble code?

To fix P26AC: Check the integrity of wires and connections in the control circuit. Test valve resistance and operation. Clean connector contacts from corrosion. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P26AC?

Limited driving only, diagnose soon

How much does it cost to fix P26AC?

The estimated repair cost for P26AC is $17–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat