P021B Cylinder 8 injection time

OBD-II DTC Datasheet

Injection time cylinder 8

What does this mean?

This Diagnostic Trouble Code (DTC) is a generic transmission code, which means it applies to most OBD-II equipped vehicles, including but not limited to VW Volkswagen, Dodge, Ram, Kia, Chevrolet, GMC, Jaguar, Ford, Jeep, Chrysler, Nissan, etc. Despite the general nature, the exact repair steps may vary depending on the make / model.

A stored code P021B means that the powertrain control module (PCM) has detected a malfunction in the injection timing circuit for a specific engine cylinder. In this case, we are talking about the eighth cylinder. Consult a reliable vehicle information source to find out the exact location of the eighth cylinder of the vehicle where the P021B was stored.

In my experience, the P021B code is stored exclusively in vehicles equipped with diesel engines. Today's clean combustion (direct injection) diesel engines require extreme fuel pressure.

Because of this high fuel pressure, only qualified personnel should attempt to diagnose or repair the high pressure fuel system.

When pump injectors are used, the injection pump is driven by the engine timing chain and is synchronized according to the position of the crankshaft and camshaft. Every time the crankshaft and camshaft of the engine reach a certain point, the injection pump gives a pulse; resulting in excessive (up to 35,000 psi) fuel pressure.

Common Rail direct injection systems are synchronized with a common high pressure fuel rail and individual solenoids for each cylinder. In this type of application, a PCM or standalone diesel injection controller is used to control the timing of the injectors.

Changes in valve timing and / or crankshaft timing warn the PCM of inconsistencies at certain cylinder injection points and request a stored P021B code. Some vehicles may require multiple Fault Ignition Cycles to store this type of code and illuminate the Malfunction Indicator Lamp.

Associated injection timing codes include for cylinders 1 through 12: P020A, P020B, P020C, P020D, P020E, P020F, P021A, P021B, P021C, P021D, P021E, and P021F.

Code severity and symptoms

All regulations relating to the high pressure fuel injection system must be considered stringent and urgently addressed.

Symptoms of a P021B engine code may include:

Engine misfire, sagging or stumbling
General insufficient engine power
Characteristic diesel smell.
Reduced fuel efficiency

reasons

Possible causes for this P021B code include:

Defective fuel injection solenoid
Open or short circuit of the wiring and / or connectors in the fuel injector control circuit
Bad fuel injector
Engine timing component malfunction
Malfunction of the crankshaft or camshaft position sensor (or circuit)

Diagnostic and repair procedures

I will need a diagnostic scanner, a digital volt / ohmmeter (DVOM) and a reliable source of vehicle information to diagnose the P021B code.

Begin by visually inspecting the high pressure fuel system components and wiring harnesses. Look for signs of fuel leaks and damaged wiring or connectors.

Check the Technical Service Bulletins (TSB) that pertain to the vehicle, symptoms and codes / codes. If such a TSB is found, it will provide very useful information for diagnosing this code.

Now I would connect the scanner to the car diagnostic port and get all stored DTCs and freeze data. I like to write this information down as it can be helpful as the diagnosis progresses. I would then clear the codes and test drive the car to see if the code is cleared. If the crankshaft sensor and / or camshaft position sensor codes are stored, diagnose and repair them before attempting to diagnose the injector timing code.

If the code is reset:

If the vehicle in question is equipped with a common rail injection system, use the DVOM and vehicle information source to check the injector solenoid for the respective cylinder. Any component that does not meet manufacturer's specifications must be replaced before proceeding. After repairing/replacing suspicious parts, clear any codes that may have been stored during testing and test drive the vehicle until the PCM enters Ready Mode or the code is cleared. If the PCM does go into ready mode, then the repair was successful. If the code is reset, we can assume that the problem is still there.

If the injector solenoid is within specification, disconnect the controller and use the DVOM to test the system circuits for a short or open circuit. Repair or replace system circuits that do not meet manufacturer's specifications according to the pinout located in your vehicle information source.

A malfunctioning unit injector can almost always be associated with a failure of an engine timing component or some kind of leakage from the high pressure fuel system.

P021B should only be diagnosed by a qualified technician due to excessive fuel pressure.
Determine what type of high pressure fuel system the vehicle is equipped with before starting diagnostics.

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