Drive minimally — misfire can damage the catalytic converter. P0352 means the ECM didn't get a proper ignition confirmation from ignition coil “B” — typically cylinder 2. It points to a coil, spark plug, wiring, or ignition-driver fault on that cylinder and often appears with a cylinder-2 misfire.
What P0352 means
On coil-on-plug (DIS) ignition, each cylinder has its own coil that the ECM fires with an ignition (IGT) signal; the igniter then returns an ignition-confirmation (IGF) signal. P0352 sets when the primary/secondary circuit for coil “B” doesn't respond correctly — the ECM commanded a spark but didn't get the expected confirmation. On most inline engines coil “B” is cylinder 2. It commonly pairs with a misfire code such as P0302.
Symptoms
- Check engine light on, sometimes flashing
- Rough idle and a misfire or stumble
- Loss of power, especially under acceleration
- Hard starting
- Smell of unburned fuel from the exhaust
- Slightly worse fuel economy
Common causes
- Failed ignition coil on that cylinder
- Damaged coil connector or wiring
- Worn spark plug increasing the coil's workload
- Poor power or ground supply to the coil
- Ignition driver fault inside the ECM (rare)
Severity & driving advice
Severity: Moderate — A dead or weak cylinder dumps raw fuel into the exhaust, which can overheat and damage the catalytic converter, so repair it promptly.
Can I drive? Drive minimally — misfire can damage the catalytic converter.
Diagnostic approach
- Swap the suspect coil to another cylinder — If the fault or misfire follows the coil to the new cylinder, the coil is bad; if it stays, the problem is wiring, the plug, or the ECM circuit.
- Inspect the coil connector and wiring — Check for corroded pins, melted connectors, or chafed wires on coil C's circuit.
- Verify coil power and ground — Confirm the coil is getting battery voltage and a good ground when the key is on.
- Measure coil primary/secondary resistance — Compare the coil's windings to specification to confirm an internal failure.
- Inspect the spark plug — A worn or fouled plug raises the voltage the coil must produce and can contribute to the fault.
- Check the ECM ignition driver last — Only after the coil, plug, and wiring are proven good should the ECM's ignition circuit be suspected.
Make & model notes
Toyota / general DIS: Each cylinder has one coil, and the igniter sends an ignition-confirmation (IGF) signal back to the ECM for every firing; the standard checks are coil winding resistance and the coil's power-source voltage.
General: Coil “B” maps to cylinder 2 on typical inline engines. When one coil fails it's wise to inspect the spark plug at the same time.
FAQ
Which cylinder is coil B?
On most inline engines coil “B” is cylinder number 2. Your firing/cylinder layout confirms it for your specific engine.
Can I swap coils to test P0352?
Yes — moving the suspect coil to another cylinder is the classic test. If the fault follows the coil, replace it.
Will P0352 damage my catalytic converter?
It can. A misfiring cylinder sends unburned fuel into the exhaust, which overheats and can ruin the catalytic converter, so don't drive on it long.
Can I drive with P0352?
Only briefly. The engine will run rough and lose power, and continued misfire risks catalytic converter damage.