Ignition Coil "A" Secondary Circuit
P2302 indicates a fault in the secondary circuit of ignition coil A, which fires spark plugs to ignite the air-fuel mixture in the engine. The PCM detected abnormal voltage or resistance in the coil's output circuit, preventing proper spark generation. This causes misfires and reduced engine performance until repaired.
What You Might Notice
- Engine misfire or rough idle
- Diminished engine performance and acceleration
- Reduced fuel efficiency
- Check engine light illuminated
- Potential fuel injector disable on affected cylinder
Most Common Causes
- 1
Faulty ignition coil A
The ignition coil pack has failed internally or developed an open/short circuit in its secondary winding. This is the most common cause of P2302 codes.
- 2
Bad spark plug or damaged spark plug wire
A worn spark plug or deteriorated spark plug wire creates excessive resistance, preventing the coil from delivering proper voltage to fire the plug.
- 3
Corroded or loose coil electrical connector
Poor connections at the ignition coil terminals or wiring harness can cause intermittent or complete loss of signal between the PCM and coil.
- 4
PCM or engine control module fault
A malfunctioning engine control computer may send incorrect signals to the ignition coil or fail to recognize proper coil operation.
How to Diagnose It
- 1
Check Faulty ignition coil A — The ignition coil pack has failed internally or developed an open/short circuit in its secondary winding. This is the most common cause of P2302 codes.
- 2
Check Bad spark plug or damaged spark plug wire — A worn spark plug or deteriorated spark plug wire creates excessive resistance, preventing the coil from delivering proper voltage to fire the plug.
- 3
Check Corroded or loose coil electrical connector — Poor connections at the ignition coil terminals or wiring harness can cause intermittent or complete loss of signal between the PCM and coil.
- 4
Check PCM or engine control module fault — A malfunctioning engine control computer may send incorrect signals to the ignition coil or fail to recognize proper coil operation.
How to Fix It
- 1
Replace ignition coil A
Remove the faulty ignition coil pack from cylinder A and install a new OEM or quality replacement coil. Ensure proper seating and connector engagement before restarting the engine.
- 2
Inspect and replace spark plug wires or coil boots
Check spark plug wires for cracks, corrosion, or burns. Replace damaged wires or coil-on-plug boots that connect to cylinder A. Ensure wires are properly seated on both the coil and spark plug.
- 3
Clean or replace coil connector and wiring
Disconnect the ignition coil A connector and inspect for corrosion, bent pins, or loose contacts. Clean terminals with electrical contact cleaner and reconnect firmly, or replace the entire connector if damaged.
- 4
Test and reprogram PCM if necessary
If coil, spark plugs, and wiring are all functional, have a technician scan the PCM for corruption and reprogram or replace the engine control module if needed.
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