Pin16

P0354

Ignition Coil "D" Primary/Secondary Circuit

Severity
High
Driving
Short journeys only

A fault in the primary or secondary circuit of ignition coil "D". That coil is not firing its cylinder properly, so expect a misfire. The coil letter is the manufacturer's designation and does not necessarily correspond to the cylinder number - the vehicle's own documentation says which is which, and a misfire code stored alongside will usually name the cylinder directly.

Possible causes

What you might notice

What to check, in order

  1. Read all codes. A misfire code for a specific cylinder alongside this one identifies which coil to look at first.
  2. Swap the suspect coil with one from a neighbouring cylinder and see whether the misfire follows it. This is the single most effective test available and it costs nothing - but only do it on engines where the coils are genuinely interchangeable.
  3. Look at the spark plug for that cylinder. A worn plug makes the coil work far harder, and fitting a new coil onto a worn plug often just kills the new coil too.
  4. Check the plug well for oil. A leaking cam cover gasket fills the well and the spark tracks to earth through the oil rather than jumping the plug gap.
  5. Inspect the coil boot for cracks and carbon tracking.

Read this code from your own car

Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.

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Where this code sits