P0352
Ignition Coil B Primary/Secondary Circuit
If your vehicle's onboard computer has flagged the diagnostic trouble code P0352, it refers to a detected anomaly regarding "Ignition Coil B Primary/Secondary Circuit". This systemic engine fault needs a targeted check before symptoms expand.
Driver's Summary
P0352 is triggered when the PCM detects an abnormal condition associated with ignition coil b primary/secondary circuit. Typical symptoms include vibration under acceleration, check engine light flashing. Given the high severity of this code, continuing to drive risks significant mechanical damage. Have it diagnosed immediately.
Symptoms
Vibration under acceleration, check engine light flashing
Common Causes
- Defective ignition coil B (Cylinder 2)
- Open circuit in coil wiring
- Fouled spark plug
- Moisture in spark plug well
How to Fix
- 1 Replace ignition coil B
- 2 Check for oil/water in spark plug tube
- 3 Repair wiring to coil
- 4 Replace spark plug
Technical Explanation
Code P0352 is confirmed when the ECM's diagnostic algorithm detects a parameter deviation that persists across a defined number of consecutive drive cycles. For injector-specific codes, the ECM monitors the injector control circuit voltage drop during each pulse; a shorted or open injector presents a characteristic resistance signature that differs measurably from a healthy unit. The MIL illuminates after the fault is confirmed on two consecutive drive cycles, and the freeze frame data captured at first detection is stored in the PCM's memory for diagnostic reference.
Is It Safe to Drive?
Driving with an active P0352 fault risks accelerating damage to defective ignition coil b (cylinder 2) and related components. The longer the fault persists, the more expensive the eventual repair becomes — what starts as a sensor or solenoid issue can escalate to major mechanical failure.
Mechanic's Pro Tip
The fastest isolation technique for P0352 is the coil swap test: move the ignition coil from the affected cylinder to a neighboring cylinder and clear the code. If the misfire follows the coil, it's the coil. If it stays on the same cylinder, focus on the spark plug, injector, or compression. Never replace coils without also replacing the spark plug in that cylinder — a fouled plug will kill a new coil within weeks.
Ignition coil replacement: $100 - $250