P0478

Exhaust Pressure Control Valve A High

Severity

⚠️ Medium

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–167 (est.)

Symptoms

Check Engine Light Is On
Deterioration of vehicle dynamics
Increased fuel consumption
Unstable engine operation

Causes

Short circuit in valve control circuit
Faulty exhaust gas pressure control valve
Wiring harness damage
Problems with the engine ECU

How to Fix

Check the wiring harness for damage
Check the resistance of the exhaust gas pressure control valve
Check control circuit for short circuit
If necessary, replace the valve or repair the wiring harness
Clear the error and check if it appears again

Related codes

P0479 P0480 P0401