Technical Description of OBD-II Trouble Code
The primary control circuit for Ignition Coil B is experiencing a high voltage condition.
What is the meaning of P2304?
P2304 is a generic powertrain code that applies to many OBD-II vehicles (1996-newer), including Jeep, Ford, VW, Mini, Dodge, Chrysler, Chevrolet, and others. The exact repair steps may vary depending on the year, make, model, and powertrain configuration of the vehicle.
If your vehicle has stored a code P2304 and the malfunction indicator lamp (MIL) is illuminated, it indicates that the powertrain control module (PCM) has detected a high voltage condition in the primary control circuit of the ignition coil designated as “B.” Consult a manufacturer-specific guide to determine which circuit corresponds to “B” in your specific application.
The primary circuits of the ignition coil are the wires that supply battery voltage to the coil. Voltage is delivered through fuses, relays, and other sources. It’s important to note that the high-energy ignition boot, spark plug boot, or spark plug wire are not considered primary circuits.
Typically, the ignition coil receives battery voltage and ground. When the ground signal is momentarily interrupted, the ignition coil emits a high voltage spark that ignites the spark plug. Spark plug operation is essential for the internal combustion engine. If the primary voltage to the ignition coil is too high, high-energy voltage emission will not occur, and the engine cylinder will not generate horsepower.
Typical individual cylinder (coil-on-plug COP) ignition coils:
What is the severity of this DTC?
When a P2304 code is stored, it is important to diagnose the cause as soon as possible. The symptoms associated with this code usually require immediate attention.
What are some of the symptoms of the code?
Symptoms of a P2304 trouble code may include:
What are some of the common causes of the code?
Possible causes for this code may include:
What are some P2304 troubleshooting steps?
In order to accurately diagnose a P2304 code, you will need a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a reliable source of vehicle information.
It may be helpful to search for technical service bulletins (TSB) that match the stored code, vehicle information (year, make, model, and engine), and exhibited symptoms. This information can usually be found in your vehicle information source. If you find the appropriate TSB, it may provide a quick solution to your diagnosis.
After connecting the scanner to the vehicle diagnostic port and retrieving all stored codes and relevant freeze frame data, write down the information in case the code is intermittent. Then, clear the codes and test drive the vehicle until one of two things happens: either the code is restored or the PCM enters readiness mode.
If the PCM enters readiness mode at this point, diagnosing the code may be more challenging because it is intermittent. The condition that caused the P2304 code to be stored may need to worsen before an accurate diagnosis can be made. If the code is restored, continue with the diagnosis.
You can obtain connector face views, connector pinout charts, component locator charts, wiring diagrams, and diagnostic flow charts specific to the code and vehicle in question from your source of vehicle information.
Conduct a visual inspection of the related wiring and connectors. Repair or replace any wiring that is cut, burned, or damaged. Wiring on top of the engine is often damaged by wildlife seeking warmth in cold climates.
Use the DVOM to test the voltage and ground circuits at the ignition coil in question. If no voltage is detected, check the system relay and related fuses. Replace any defective relays and/or blown (or otherwise defective) fuses as necessary.
If voltage and ground are detected at the coil, test the corresponding ground circuit at the PCM connector with the engine running. If a ground pulse is detected there, suspect an open circuit between the coil in question and the PCM. If no ground pulse is found, suspect a defective PCM or a programming error.
