P239D

Diesel Intake Air Flow B Control System - Low Air Flow Detected

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$17–89 (est.)

Symptoms

Reduced engine power
Increased fuel consumption
Unstable engine idling
Black smoke from the exhaust pipe
Check Engine Light Illuminates

Causes

Air filter clogged
Malfunction of the mass air flow sensor (MAF)
Problems with the EGR system
Air leak in the intake tract
Turbocharger malfunction

How to Fix

Check and replace the air filter if necessary
Test and replace the mass air flow sensor if faulty
Check the EGR system for blockage or malfunction
Inspect the intake tract for air leaks
Check the operation of the turbocharger

Related codes

P239E P239F P239C