P04A5

Symptoms

• Check Engine Light Is On
• Increased emissions (violation of environmental standards)
• Malfunction of the EGR system (detonation, fuel consumption)
• Deterioration of engine warm-up in cold weather
• Reduced particulate filter efficiency (diesel)
• Possible emergency mode with power limitation

Causes

• Valve jamming due to carbon deposits and tar deposits
• Valve stem corrosion in exhaust tract
• Broken valve return spring
• Valve deformation due to high temperatures
• Faulty pneumatic or electric valve actuator
• Vacuum leak in actuator (vacuum type)

How to Fix

1. Carry out a valve activation test through a scanner: check the response to ECU commands
2. Visually inspect the valve: carbon deposits on the stem and seat
3. Attempt to manually move the valve stem (with safe access to a cold engine)
4. Treat the valve mechanism with penetrating lubricant and blowing - an attempt to restore mobility
5. Check the drive: on the vacuum type - tightness of the tubes; on electric - power and signal
6. Clean the valve from carbon deposits or replace the assembly
7. After repair, perform an activation test to ensure full valve travel
8. Reset codes and take a test drive

Related codes

Error P04A5 by Vehicle Brand