P049A

Symptoms

• Check Engine Light Is On
• Reduced engine power and thrust
• Unstable operation at idle
• Detonation under load
• Increased fuel consumption
• Increased exhaust toxicity
• Possible activation of emergency mode (power limitation)

Causes

• Clogged EGR valve B (carbon deposits block the flow area)
• Clogged recirculation channels (carbon deposits in pipes or intake manifold)
• Faulty EGR valve B (mechanical failure, stuck)
• Clogged or faulty EGR cooler (recirculated gas cooler)
• Faulty flow sensor giving false readings
• Crack in EGR valve body or pipes

How to Fix

1. Read All Codes - P049A often appears along with P049B (Insufficient Flow)
2. Carry out an activation test of the EGR valve B through a scanner - make sure it opens/closes
3. Visually inspect the EGR valve B and tubes for carbon deposits and mechanical damage
4. Clean the EGR valve with a specialized cleaner or replace it if it is mechanically jammed
5. Check the EGR channels in the intake manifold - they are often clogged with hard carbon deposits
6. Check the EGR cooler for permeability (if equipped)
7. On a diesel engine, check the particulate filter - its blockage affects the operation of the EGR
8. Reset codes, test drive with EGR data monitoring

Related codes

Error P049A by Vehicle Brand