P01EC

Engine Coolant Heater B Control Circuit/Open

Severity

⚠️ Medium

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–167 (est.)

Symptoms

Long engine warm-up in cold weather
Increased fuel consumption
Unstable engine operation at idle
Check Engine Light on Dashboard

Causes

Broken or damaged wiring harness
Coolant heater malfunction
Relay or fuse problems
Short circuit in the circuit
Engine control unit malfunction

How to Fix

Check heater circuit fuse and relay
Inspect the wiring harness for damage
Check heater resistance
Check the voltage at the heater terminals
If necessary, replace the heater or repair the wiring
Reset the error and check if it returns

Related codes

P01EB P01ED P0597