P2302
Ignition Coil "A" Secondary Circuit
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The P2302 code indicates a malfunction in the secondary circuit of ignition coil A. The secondary circuit is the high-voltage side of the ignition coil — the part that generates the tens of thousands of volts needed to fire the spark plug. When the PCM detects that this circuit is not performing within expected parameters, it sets this code.
This is an important code to address because the secondary circuit is what actually fires the spark plug. A malfunction here means the affected cylinder may not be getting a proper spark, leading to misfires, rough running, and wasted fuel. Prolonged misfiring can damage your catalytic converter, turning an affordable repair into an expensive one.
The best approach is to start with the simplest and cheapest components first. Inspect and replace the spark plug for the affected cylinder, then check the spark plug wire or coil-on-plug boot for cracks, carbon tracking, or wear. If those are fine, replace the ignition coil itself. Most of these parts are inexpensive and the work is manageable for a DIYer with basic tools.
Severity
Symptoms
- •Check Engine Light is on
- •Engine misfires or runs rough
- •Noticeable lack of power
- •Hard starting or extended cranking
- •Rough or unstable idle
- •Increased fuel consumption
Likely Causes
The secondary winding inside the coil (the high-voltage side that fires the spark plug) has failed or degraded.
A worn or carbon-fouled spark plug increases the resistance the coil must overcome, which can cause secondary circuit faults.
Cracked, arcing, or carbon-tracked spark plug wires or coil boots allow voltage to leak, triggering a secondary circuit fault.
Damaged wiring or loose connections between the PCM and ignition coil can affect secondary circuit monitoring.
The control module monitoring the secondary circuit may be providing false readings due to internal failure.
Estimated Cost
Professional Repair
Includes parts + labor
Common Fixes
- Replace ignition coil A
- Replace spark plug for cylinder A
- Replace spark plug wire or coil boot
- Repair or replace damaged wiring and connectors