Technical Description of OBD-II Trouble Code
Issue with Ignition Coil J Secondary Circuit
What is the meaning of P2329?
P2329 is a generic powertrain code that applies to many OBD-II vehicles (1996-newer), including Jeep, Dodge, Mercedes-Benz, Chrysler, Ram, Porsche, etc. The exact repair steps may vary depending on the year, make, model, and powertrain configuration of the vehicle. However, this code is most commonly found on Jeep and Dodge vehicles.
If your vehicle has stored a code P2329 and the malfunction indicator lamp (MIL) is illuminated, it indicates that the powertrain control module (PCM) has detected an abnormal voltage condition in the secondary control circuit of the ignition coil designated with the letter J. Consult a manufacturer-specific guide to determine which circuit corresponds to the “J” designation in your specific application.
The primary circuits of the ignition coil are responsible for supplying battery voltage to the coil. This voltage is delivered through fuses, relays, and other sources. The secondary coil circuits include the high-energy ignition boot, spark plug boot, or spark plug wires, which transfer the high-energy spark from the coil to the spark plug.
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. Insufficient primary voltage to the ignition coil will prevent the emission of high-energy voltage, resulting in the engine cylinder not producing horsepower.
Illustration of typical individual cylinder (coil-on-plug COP) ignition coils:
What is the severity of this DTC?
When a P2329 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 P2329 trouble code may include:
What are some of the common causes of the code?
Possible causes for this code may include:
What are some P2329 troubleshooting steps?
In order to accurately diagnose a code P2329, 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 a relevant 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 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 P2329 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. Spark plug wires and boots should be replaced as part of scheduled maintenance. If the vehicle has exceeded the recommended maintenance interval for a tune-up, suspect that bad spark plug wires/boots are causing the stored P2329 code.
Defective spark plug boots that are torn, burnt, or contaminated by fluid should be considered faulty. 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 no HEI is detected, disconnect the spark plug wire from the coil and check for 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. HEI should be tested carefully with the engine running.
