OBD Guide

P0E77

Coolant Bypass Valve A Control Circuit High

P0E77 is an OBD-II diagnostic trouble code meaning: Coolant Bypass Valve A Control Circuit High. Common causes: open circuit in valve control circuit, short circuit to positive in the circuit. Estimated repair cost: $17–56.

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

Symptoms

  • Engine overheating
  • Insufficient engine warm-up
  • Unstable engine operation
  • Increased fuel consumption
  • Check Engine Light Illuminates

Causes

  • Open circuit in valve control circuit
  • Short circuit to positive in the circuit
  • Coolant bypass valve malfunction
  • Wiring Harness Problems
  • Engine control unit (ECU) malfunction

How to Fix

  1. Check valve control circuit integrity
  2. Check the resistance of the coolant bypass valve
  3. Inspect the wiring harness for damage
  4. Check the operation of the coolant bypass valve
  5. If necessary, replace the valve or repair the circuit

Related codes

Error P0E77 by Vehicle Brand

FAQ

What does the P0E77 code mean?

P0E77 is an OBD-II diagnostic trouble code that indicates: Coolant Bypass Valve A Control Circuit High

What causes a P0E77 error code?

The most common causes of P0E77 include: Open circuit in valve control circuit; Short circuit to positive in the circuit; Coolant bypass valve malfunction; Wiring Harness Problems.

How do I fix a P0E77 diagnostic trouble code?

To fix P0E77: Check valve control circuit integrity. Check the resistance of the coolant bypass valve. Inspect the wiring harness for damage. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P0E77?

Limited driving only, diagnose soon

How much does it cost to fix P0E77?

The estimated repair cost for P0E77 is $17–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat