The 2.0 diesel of 1, 3 and 5 Series. Infamous for timing chain stretch with the chain at the gearbox side - treat P0016 dead seriously on this engine.
Click a code for the full breakdown: symptoms, causes, and whether you can keep driving.
Turbocharger Underboost
The turbo is producing less boost pressure than the ECU requests.
Crankshaft/Camshaft Position Correlation (Bank 1 Sensor A)
The crankshaft and camshaft positions do not match what the ECU expects - the mechanical timing may be off.
Diesel Particulate Filter Efficiency Below Threshold
The DPF is not trapping soot as it should - it may be damaged, removed, or overloaded.
EGR Flow Insufficient
The exhaust gas recirculation valve is not flowing enough exhaust back into the intake, usually due to carbon buildup.
Fuel Rail/System Pressure Too Low
Measured fuel pressure is below what the ECU commands - the engine may be starved of fuel under load.
Glow Plug Module Control Circuit (Diesel)
The control circuit of the diesel glow plug module has a fault.
Turbocharger Overboost Condition
Boost pressure exceeded the safe limit - the wastegate or boost control is not relieving pressure.
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