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P2308 — Ignition Coil C Secondary Circuit

Manufacturer-specificPowertrain (engine & transmission)

P2308 indicates a malfunction in the secondary circuit of ignition coil C, meaning the PCM is detecting an abnormal voltage or resistance condition when the coil is supposed to fire.

Symptoms

What causes it — most likely first

1. Faulty ignition coil C

The coil may have an internal short or open circuit, causing the secondary voltage to be out of spec.

2. Damaged coil wiring or connector

Corrosion, frayed wires, or a loose connector can interrupt the secondary circuit and trigger the code.

3. High resistance or short to ground in the coil's secondary circuit

A short to ground or excessive resistance in the coil's secondary leads can cause abnormal readings.

4. Faulty PCM secondary circuit driver

The PCM's driver transistor for coil C may be malfunctioning, though this is less common than coil or wiring issues.

How it's diagnosed

  1. Verify the code is present and no other related codes exist.
  2. Inspect coil C wiring and connector for corrosion, damage, or looseness; repair as needed.
  3. Measure resistance of coil C secondary circuit (typically 5–10 kΩ) and compare to specification.
  4. Swap coil C with a known good coil from another cylinder and clear the code; if the code follows the coil, replace the coil.
  5. If the coil and wiring are good, test the PCM driver output voltage for coil C; replace PCM only as a last resort.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationManufacturer-specific (P1/B1/C1/U1)
Related codesP2300 — Ignition Coil Primary Control Circuit P2301 — Ignition Coil Primary Control Circuit P2302 — Ignition Coil Secondary CircuitP2303 — Ignition Coil B Primary Control CircuiP2304 — Ignition Coil B Primary Control CircuiP2305 — Ignition Coil B Secondary Circuit

Vehicles this code applies to

The definition is universal; the diagnostics are engine-specific. Open your vehicle for the codes documented for it:

2010 Jaguar XFR2010 Jaguar XF

Frequently asked

Can the PCM be the cause of a P2308 code?

It is possible but uncommon. The PCM’s driver for coil C can fail, but most cases are due to a bad coil, wiring, or connector.

Do I need to replace the entire ignition coil pack for this code?

Not necessarily. Often only coil C is defective. Testing coil resistance and swapping coils can confirm which unit needs replacement.

Why does the code reference the 'secondary circuit'?

The secondary circuit is the high‑voltage side of the coil that creates the spark. The PCM monitors voltage and resistance there; any abnormal condition sets P2308.

Is it ever appropriate to replace the PCM for P2308?

Only after confirming that the coil and all related wiring are functioning correctly and the PCM driver output is out of spec. Replacing the PCM without this verification is usually unnecessary.