P01F8

Engine Coolant Heater A Control Circuit Driver Current/Temperature Too High

Severity

⚠️ Medium

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–167 (est.)

Symptoms

Check Engine Light
Reduced preheating efficiency
Problems starting in cold weather
Heater overheating

Causes

Short circuit in the heater circuit
Control driver failure
Heater overheating
Wiring Harness Problems
Engine control unit malfunction

How to Fix

Diagnostics of the heater control circuit
Checking the resistance and insulation of the heater
Inspect the wiring harness for damage
Checking power and ground circuit
Testing the control driver
Replacing faulty components
Resetting the error and checking the system operation

Related codes

P01F7 P01F9 P0128