OBD-II Code P0352 — What It Means & How to Fix It

What Does This Error Mean?

P0352 means the PCM detected a problem in the primary circuit of ignition coil B. Coil B typically serves cylinder 2, though this varies by manufacturer. A fault in this circuit can prevent the cylinder from getting spark. Symptoms include a rough idle, misfire on cylinder 2, and reduced power.

Affected Models

All vehicles 1996+
Common in Ford EcoBoost four-cylinder engines
Common in Chevrolet and GMC with coil-on-plug ignition
Common in Dodge Charger and Challenger V6 and V8
Common in Nissan and Infiniti V6 engines

Common Causes

Failed ignition coil B with a shorted or open primary winding
Corroded or damaged wiring connector at the coil B position
Broken wire in the coil B primary circuit harness
Fouled or damaged spark plug creating excessive load on the coil
PCM ignition driver failure on the coil B circuit (uncommon)

How to Fix It

Identify coil B on your engine. In most coil-on-plug setups, coil B sits above cylinder 2. On some engines with a coil pack covering multiple cylinders, coil B is a specific terminal on that pack. Inspect the connector first.

Check your vehicle's service manual to confirm which coil corresponds to cylinder 2 — labeling varies by manufacturer.
Test primary winding resistance with a multimeter. Disconnect the coil and probe the primary terminals. Normal resistance is typically 0.4-2.0 ohms. A zero reading means a short; infinite reading means an open circuit.

If resistance is within spec, the coil winding is likely fine and the problem may be in the wiring or connector.
Swap the coil B ignition coil with a coil from a different cylinder. Clear all codes and do a 10-15 mile test drive. If the fault code follows the coil to its new location, the coil is definitely bad.

If the code stays on coil B's circuit after swapping a known good coil in, the wiring or PCM driver is the issue.
Replace the spark plug in the cylinder served by coil B. A worn or fouled plug puts excessive strain on the coil and can cause premature coil failure. Replace both the coil and plug together for the best long-term result.

Spark plug replacement intervals vary: copper plugs every 30,000 miles, iridium or platinum plugs every 60,000-100,000 miles.
Trace the coil B wiring harness and look for broken wires, melted insulation, or pulled connector pins. Repair any damage, clear the code, and test drive. Monitor for misfire counts on a scan tool to confirm the repair.

After any ignition repair, confirm with live data that misfire counts for the affected cylinder drop to zero.

When to Call a Professional

If coil and plug replacement don't resolve the code, have the wiring circuit tested professionally. A technician can check the PCM's coil trigger signal with an oscilloscope. This quickly determines whether the PCM is functioning correctly. Diagnosis typically costs $80-$130. Coil and plug replacement is $50-$150 in parts plus labor.

Frequently Asked Questions

Can I drive with P0352?

Short distances are possible, but not recommended. A misfiring cylinder sends raw fuel into the exhaust. This overheats and can destroy the catalytic converter. Catalytic converter replacement can cost $500-$2,000 depending on the vehicle. Fix P0352 sooner rather than later.

What is the coil B primary circuit exactly?

Each ignition coil has two electrical circuits. The primary circuit uses 12V power switched by the PCM. When the PCM pulses the primary circuit, it builds a magnetic field. When the PCM cuts power, that field collapses and creates a 30,000+ volt spark. P0352 means the PCM detected a problem in that 12V control circuit.

How much does it cost to fix P0352?

An ignition coil costs $20-$80 depending on the vehicle. A spark plug is $5-$25. Labor for a coil-on-plug replacement is usually 30-60 minutes. Total repair at a shop runs approximately $100-$300. It's a straightforward DIY repair if you're comfortable with basic tools.