OBD Guide

P2B72

Coolant Heater A Control Circuit/Open

P2B72 is an OBD-II diagnostic trouble code meaning: Coolant Heater A Control Circuit/Open. Common causes: heater control circuit open, coolant heater malfunction. Estimated repair cost: $17–56.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–56 (est.)

Symptoms

  • Extended engine warm-up time
  • Unstable operation at idle
  • Check Engine light comes on
  • Reduced engine efficiency in cold weather

Causes

  • Heater control circuit open
  • Coolant heater malfunction
  • Relay or fuse problems
  • Control module malfunction
  • Corrosion or poor contact in connectors

How to Fix

  1. Check heater circuit fuse and relay
  2. Inspect connectors and wires for damage
  3. Check heater resistance
  4. Diagnose the control module
  5. Replace coolant heater if necessary

Related codes

Error P2B72 by Vehicle Brand

FAQ

What does the P2B72 code mean?

P2B72 is an OBD-II diagnostic trouble code that indicates: Coolant Heater A Control Circuit/Open

What causes a P2B72 error code?

The most common causes of P2B72 include: Heater control circuit open; Coolant heater malfunction; Relay or fuse problems; Control module malfunction.

How do I fix a P2B72 diagnostic trouble code?

To fix P2B72: Check heater circuit fuse and relay. Inspect connectors and wires for damage. Check heater resistance. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P2B72?

Yes, but get it checked soon

How much does it cost to fix P2B72?

The estimated repair cost for P2B72 is $17–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat