Ignition Coil "C" Secondary Circuit
P2308 indicates a malfunction in the secondary circuit of Ignition Coil C, which is responsible for producing the high-voltage spark for one or more cylinders. When this circuit fails, the affected cylinder(s) cannot fire properly, causing misfires and reduced engine performance.
What You Might Notice
- Engine misfire or rough idle
- Diminished engine performance and power loss
- Reduced fuel efficiency
- Check Engine Light illuminated
- Possible fuel injector disabling by PCM for affected cylinder
Most Common Causes
- 1
Faulty Ignition Coil C
The ignition coil itself may have internal winding damage, insulation failure, or coil pack degradation, preventing proper secondary voltage output.
- 2
Damaged Ignition Coil Wiring or Connector
Corroded, loose, or broken wiring connections and connectors between the coil and PCM can interrupt the control signal or secondary circuit continuity.
- 3
Spark Plug or Spark Plug Wire Issues
A worn spark plug or damaged high-tension wire connected to Ignition Coil C may prevent proper spark generation or create excessive resistance.
- 4
PCM or Control Circuit Fault
The Engine Control Module may have internal faults in the ignition coil driver circuit, or the coil control signal pathway may be compromised by corrosion or wiring damage.
How to Diagnose It
- 1
Check Faulty Ignition Coil C — The ignition coil itself may have internal winding damage, insulation failure, or coil pack degradation, preventing proper secondary voltage output.
- 2
Check Damaged Ignition Coil Wiring or Connector — Corroded, loose, or broken wiring connections and connectors between the coil and PCM can interrupt the control signal or secondary circuit continuity.
- 3
Check Spark Plug or Spark Plug Wire Issues — A worn spark plug or damaged high-tension wire connected to Ignition Coil C may prevent proper spark generation or create excessive resistance.
- 4
Check PCM or Control Circuit Fault — The Engine Control Module may have internal faults in the ignition coil driver circuit, or the coil control signal pathway may be compromised by corrosion or wiring damage.
How to Fix It
- 1
Replace Ignition Coil C
Remove and replace the faulty ignition coil pack for Cylinder C. Ensure proper seating and secure all electrical connections. Test for proper spark output after installation.
- 2
Inspect and Repair Coil Wiring and Connectors
Check the wiring harness and connector pins for corrosion, damage, or loose connections between Ignition Coil C and the PCM. Clean, repair, or replace damaged wiring as needed.
- 3
Replace Spark Plug and Check Spark Plug Wire
Remove and replace the spark plug for Cylinder C with the correct specification. Inspect the spark plug wire or coil-to-plug connection for cracks, burns, or poor contact and replace if necessary.
- 4
Diagnose PCM and Control Circuit
If coil, wiring, and spark plugs are confirmed good, perform advanced diagnostics on the PCM ignition coil driver circuit using a scope or PCM-specific diagnostic tool to identify internal module faults.
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