Code
P1368
DS
P — Powertrain
Ignition coil 3 control spark time
AI status
Completed
Completed
100%
Causes
- Open or short in coil 3 primary wiring or connector
- Faulty ignition coil (coil pack or coil-on-plug) for cylinder 3
- Poor battery or supply voltage to ignition driver circuit
- Faulty ignition driver/transistor in the engine control module (ECU)
- Crank or cam position sensor error or timing/sync issue
- Corroded or loose ground at coil or ECU
Symptoms
- Check Engine Light (MIL) illuminated
- Rough idle or vibration at idle
- Misfire felt on cylinder 3, reduced power under load
- Poor fuel economy, hesitation or surging
- Possible increased emissions or failed emissions test
- Intermittent or hard-start conditions
What to check
- Read freeze-frame and live data for engine speed, load, misfire counters and battery voltage at time of fault
- Confirm presence of related misfire codes (P03xx) and other ignition coil codes
- Visually inspect coil 3, connector and wiring for damage, corrosion or corrosion in pins
- Check battery and charging system voltage under cranking and run conditions
- Wiggle test connectors and harness while monitoring live data for changes (do gently)
- Check camshaft and crankshaft position sensor signals and timing (use scope if available)
Signal parameters
- Primary coil resistance (typical): ~0.4–2.5 Ω (varies by coil type; consult factory spec)
- Secondary coil resistance (typical): ~5 kΩ–15 kΩ (consult factory data)
- Primary drive voltage: near battery voltage during dwell (~11–14.5 V)
- Dwell/pulse width: commonly 2–5 ms at idle (varies by engine speed/load; consult factory)
- Ignition event timing: should align with commanded crank angle within a few degrees (verify with cam/crank sync)
Diagnostic algorithm
- Retrieve full freeze-frame data and all stored codes. Note battery voltage and engine conditions when the fault set.
- Inspect coil 3 and connector physically; repair any damaged terminals, pins or boots. Ensure good ground/retainer seating.
- Check battery and charging system; ensure stable supply voltage during cranking and at idle.
- Measure coil 3 primary and secondary resistance and compare to factory specification. Replace coil if out of range or open/shorted.
- Using a lab scope or ignition analyzer, capture primary and secondary ignition waveforms on coil 3 and compare to a known-good cylinder. Look for missing or truncated pulses, abnormal dwell or timing shift. Use appropriate HV probe and safety practices.
- Check wiring between coil 3 and ECU for opens/shorts/low resistance and for intermittent faults (backprobe connector, wiggle test while monitoring).
- Swap coil 3 with a known-good coil (if feasible) and re-test to see if code moves to another cylinder — this helps isolate coil vs. ECU/driver/wiring.
- Verify camshaft and crankshaft position sensor signals and timing; correct any timing/sync issues that could cause mis-timed spark events.
- If wiring and coil check good and problem follows no swap, consider ECU ignition driver diagnostics or replacement and check for manufacturer software updates/TSBs before ECU replacement.
- Clear codes and perform a road test under similar conditions to verify repair. Monitor for reappearance of fault and re-check freeze-frame if it returns.
Likely causes
- Damaged/loose connector or wiring to coil 3
- Failed ignition coil (internal short or degraded primary/secondary)
- Faulty coil driver in ECU (less common)
- Incorrect cam/crank timing or faulty cam/crank sensor causing timing mismatch
Fault status
Status
P1368 — Ignition coil 3 control: irregular/missing spark or timing event detected. Check coil, wiring, supply and coil driver/ECU.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
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