P21B6

Cold Start Cylinder 1 Injection Timing

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$33–167 (est.)

Symptoms

Unstable engine operation when cold
Increased fuel consumption
Difficulty starting in cold weather
Loss of engine power
Dips during acceleration

Causes

Malfunction of the fuel injector of cylinder 1
Problems with the high pressure fuel pump
Fuel system contamination
Coolant temperature sensor malfunction
Problems with the engine ECU or its software

How to Fix

Check the condition and performance of the cylinder 1 injector
Diagnose the operation of the high pressure fuel pump
Clean the fuel system (injectors, fuel tank)
Check the operation of the coolant temperature sensor
Flash or replace the engine ECU if necessary

Related codes

P21B0 P21B1 P21B5 P21B7