P021C Cylinder 9 Injection Timing
OBD-II Trouble Code Technical Description
Cylinder 9 Injection Timing
What does that mean?
This diagnostic trouble code (DTC) is a generic powertrain 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. Although generic, the exact repair steps may vary depending on make/model.
A stored code P021C means that the powertrain control module (PCM) has detected a malfunction in the injection timing circuit for a particular cylinder of the engine. In this case, the cylinder in question is cylinder nine. Consult a reliable vehicle information source for the exact location of cylinder number nine for the vehicle in which the P021C has been stored.
It has been my experience that a code P021C is stored exclusively in vehicles equipped with diesel engines. Today’s clean burning (direct injection) diesel engines require extreme levels of fuel pressure.
Because of this high degree of fuel pressure, only qualified personnel should attempt to diagnose or repair the high-pressure fuel system.
When unit injectors are utilized, the high pressure injection pump is driven by the engine timing chain and timed according to the position of the crankshaft and camshaft/s. Every time the engine crankshaft and camshaft/s reach a certain point, the high pressure injection pump is pulsed; resulting in an extreme degree (up to 35,000 psi) of fuel pressure.
Common rail direct injection systems are timed using a common high-pressure fuel rail and individual solenoids for each cylinder. In this type of application the PCM or a stand-alone diesel injection controller is used to control injector timing.
Variations in camshaft and/or crankshaft timing alert the PCM of inconsistencies in specific cylinder injection timing and prompt a stored code P021C. Some vehicles may require multiple ignition cycles with a failure for this type of code to be stored and a malfunction indicator lamp to be illuminated.
Related injection timing codes include from cylinders 1 through 12: P020A, P020B, P020C, P020D, P020E, P020F, P021A, P021B, P021C, P021D, P021E, and P021F.
Code Severity & Symptoms
All codes related to the high-pressure fuel injection system should be considered severe and addressed with a degree of urgency.
Symptoms of a P021C engine code may include:
Engine misfire, sag, or stumble General lack of engine performance Distinctive odor of diesel fuel Reduced fuel efficiencyCauses
Possible causes for this P021C code include:
Defective fuel injection solenoid Open or shorted wiring and/or connectors in fuel injector control circuit Bad fuel injector Engine timing component failure Crankshaft or camshaft position sensor (or circuit) failureDiagnostic and Repair Procedures
I would require a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a reliable vehicle information source to diagnose a code P021C.
Begin with a visual inspection of high-pressure fuel system related components and wiring harnesses. Look for signs of fuel leakage as well as damage to wiring or connectors.
Check for technical service bulletins (TSB) which pertain to the vehicle, symptoms, and code/s in question. If such a TSB is located, it will provide very helpful information for diagnosing this code.
Now, I would connect the scanner to the vehicle diagnostic port and retrieve all stored trouble codes and freeze frame data. I like to make a note of this information as it may prove beneficial as the diagnosis unfolds. Next, I would clear the codes and test-drive the vehicle to see if the code is reset. If there are crankshaft sensor and/or camshaft position sensor codes stored, diagnose and repair those before attempting to diagnose the injec
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