Technical Description of OBD-II Trouble Code
Secondary Circuit of Ignition Coil A
What is the meaning of P2302?
This diagnostic trouble code (DTC) is a generic powertrain code that applies to many OBD-II vehicles (1996-newer). This includes vehicles from Jeep, Dodge, Mercedes-Benz, Chrysler, Ram, Porsche, etc. Although it is a generic code, the exact repair steps may vary depending on the year, make, model, and powertrain configuration. However, it is commonly found on Jeep and Dodge vehicles.
If your vehicle has stored a code P2302, along with a malfunction indicator lamp (MIL), it indicates that the powertrain control module (PCM) has detected an abnormal voltage condition in the secondary control circuit of the ignition coil designated as “A.” Consult a manufacturer-specific guide to determine which circuit is designated as “A” for 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 various other sources. The secondary coil circuits include the high-energy ignition boot, spark plug boot, or spark plug wires, which are responsible for transferring the high-energy spark from the coil to the spark plug.
Typically, the ignition coil is supplied with battery voltage and ground. When the ground signal is momentarily interrupted, the ignition coil emits a high-voltage spark, which ignites the spark plug. The operation of the spark plug is essential for the internal combustion engine. If the primary voltage to the ignition coil is insufficient, high-energy voltage emission will not occur, and the engine cylinder will not produce horsepower.
Typical individual cylinder (coil-on-plug COP) ignition coils:
What is the severity of this DTC?
When a P2302 is stored, the cause should be diagnosed as soon as possible. Symptoms that likely accompany these codes usually require immediate attention.
What are some of the symptoms of the code?
Symptoms of a P2302 trouble code may include:
What are some of the common causes of the code?
Causes for this code may include:
What are some P2302 troubleshooting steps?
In order to accurately diagnose a code P2302, you will need a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a reliable source of vehicle information.
You can save time and trouble by searching for technical service bulletins (TSB) that match the stored code, vehicle (year, make, model, and engine), and exhibited symptoms. This information can 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: the code is restored or the PCM enters readiness mode.
If the PCM enters readiness mode at this point, the code may be more difficult to diagnose because it is intermittent. The condition that caused the P2302 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 (related to the code and vehicle in question) using your source of vehicle information.
Perform a visual inspection of the related wiring and connectors. Repair or replace any wiring that has been cut, burned, or damaged. Scheduled maintenance includes the replacement of spark plug wires and boots. If the vehicle in question has exceeded the recommended maintenance interval for a tune-up, suspect bad spark plug wires/boots as the cause of a stored P2302.
Consider spark plug boots that are torn, burnt, or contaminated by fluid as defective. Gain access to the junction between the ignition coil and the spark plug wire. Check for high-energy ignition (HEI) at the spark plug. If none is detected, disconnect the spark plug wire from the coil and check for any HEI there. If there is HEI at the spark plug but not at the coil, suspect a bad plug or a PCM error. If there is no HEI at the spark plug but it is strong at the coil, suspect a bad plug wire or boot. If there is no HEI at the coil, suspect a defective coil. HEI should be tested (carefully) with the engine running.
