P20D4

Exhaust Aftertreatment Fuel Injector B Control Circuit High

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$56–167 (est.)

Symptoms

Check Engine Light Is On
Reduced engine power
Increased fuel consumption
Problems with diesel particulate filter regeneration
Increased level of harmful emissions

Causes

Broken or damaged control circuit wires
Oxidation of injector connector contacts
Fuel injector B itself is faulty
Problems with the engine control unit
Short circuit in control circuit

How to Fix

Check the integrity of the wiring and contacts in the control circuit
Measure the injector resistance (compare with the norm)
Check the voltage at the injector connector
If necessary, replace injector B of the aftertreatment system
Check the operation of the system after repair using an OBD-II scanner

Related codes

P20D3 P20D5 P20D6