P2308 Ignition Coil C Secondary Circuit
OBD2 Error Codes

P2308 Ignition Coil C Secondary Circuit

P2308 Ignition Coil C Secondary Circuit

OBD-II DTC Datasheet

Secondary circuit of ignition coil C

What does P2308 mean?

This Diagnostic Trouble Code (DTC) is a generic transmission code and applies to many OBD-II vehicles (1996 and newer). This may include, but is not limited to, Jeep, Dodge, Mercedes-Benz, Chrysler, Ram, Porsche, etc. Despite the general nature, the exact repair steps may vary depending on the model year, make, model and transmission configuration. ... Oddly enough, this code is most often found on Jeep and Dodge vehicles.

If your vehicle has a code P2308 followed by a malfunction indicator lamp (MIL), it means that the powertrain control module (PCM) has detected an abnormal voltage condition in the secondary control circuit of the ignition coil, indicated by the letter C. Refer to the manufacturer's manual to determine which circuit "C" is suitable for your specific application.

The ignition coil primary circuits are the wires that supply battery voltage to the coil. Voltage is supplied 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 interrupted (momentarily), the ignition coil emits a high voltage spark which also ignites the spark plug. The operation of a spark plug is a necessary component of an internal combustion engine. If the primary voltage at the ignition coil is insufficient, no high voltage surge will occur and the engine cylinder will not produce horsepower.

Typical individual cylinder (coils on the KS candle) ignition coils: P2308 Ignition Coil C Secondary Circuit

What is the severity of this DTC?

When P2308 is saved, the cause should be diagnosed as soon as possible. The symptoms likely to accompany these codes usually require immediate attention.

What are some of the symptoms of the code?

Symptoms of a P2308 trouble code may include:

  • Engine misfire
  • Reduced engine performance
  • Reduced fuel efficiency
  • Other related codes
  • Fuel injector operation for the affected cylinder may be disabled by the PCM

What are some of the common causes for the code?

Reasons for this code may include:

  • Bad spark plug wire or boot
  • Defective relay or blown fuse (fuse)
  • Open or short circuit in wiring or wire connectors (wildlife damage)
  • Defective ignition coil
  • Faulty camshaft or crankshaft sensor or wiring

What are some steps to troubleshoot the P2308?

You will need a diagnostic scanner, digital volt / ohmmeter (DVOM), and reliable vehicle information source to accurately diagnose the P2308 code.

You can save time and time by searching for Technical Service Bulletins (TSBs) that reproduce the stored code, vehicle (year, make, model, and engine) and symptoms found. This information can be found in your vehicle information source. If you find the right TSB, it can quickly fix your problem.

After you connect the scanner to the vehicle diagnostic port and get all stored codes and associated freeze frame data, write down the information (in case the code turns out to be intermittent). After that, clear the codes and test drive the car until one of two things happens; the code is restored or the PCM enters ready mode.

The code may be more difficult to diagnose if the PCM enters ready mode at this point because the code is intermittent. The condition that led to the persistence of P2308 may need to worsen before an accurate diagnosis can be made. If the code is restored, continue diagnostics.

You can get connector views, connector pinouts, component locations, wiring diagrams, and diagnostic block diagrams (related to the code and the vehicle in question) using your vehicle information source.

Visually inspect the associated wiring and connectors. Repair or replace cut, burnt, or damaged wiring. Routine maintenance includes replacement of wires and spark plug anthers. If the vehicle in question is outside the recommended maintenance interval for tuning, suspect faulty spark plug wires / boots are the cause of the stored P2308.

Torn, burnt, or fluid contaminated spark plug covers should be considered defective. Access the junction between the ignition coil and spark plug wire. Check for High Energy Ignition (HEI) on the spark plug. If nothing is found, disconnect the spark plug wire from the coil and see if any HEI is found there. If there is an HEI on the spark plug, suspect the plug is faulty or there is a PCM error. If there is no HEI on the spark plug but is strong on the coil, suspect a faulty spark plug wire or boot. If there is no HEI on the coil, suspect the coil is defective. The HEI should be checked (thoroughly) with the engine running.

  • P2308 can be repaired by setting up maintenance, but do diagnostic work to make sure

Related DTC discussions

  • 2004 RAM misfires were p2308 now p0302First ... I'm not a mechanic. I can only convey what I see and what my mechanic has done. A few weeks ago, my truck began to shake and malfunction. Threw out the code P2308 of the ignition coil C of the secondary circuit. I replaced the coil and stopped practicing for about 10 days. I started doing it ... 
  • Need help with new codes P2302 and P2308I replaced all eight coils with new spark plugs and the new wires got new codes, trying to figure out that any help would be kindly appreciated…. 2004 Dodge Ram 1500 quad cab SLT 5.7l v8 hemi Magnum Diagnostic Trouble Code (DTC) Detected Code P2302 Low Severity Ignition Coil "A" Secondary Circuit ... 

Need more help with the P2308 code?

If you still need help with DTC P2308, post a question in the comments below this article.

NOTE. This information is provided for informational purposes only. It is not intended to be used as a repair recommendation and we are not responsible for any action you take on any vehicle. All information on this site is protected by copyright.

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