Ignition Coil D Primary/Secondary Circuit Malfunction
P0354 indicates a malfunction in the ignition coil D primary or secondary circuit, which prevents proper spark generation for cylinder 4. The powertrain control module detected an electrical problem in the coil driver circuit, such as an open, short, or connection fault.
What You Might Notice
- Check engine light illuminated
- Engine misfire on cylinder 4
- Rough idle or hesitation under acceleration
- Loss of power or reduced fuel economy
- Intermittent stalling or difficulty starting
Most Common Causes
- 1
Defective Coil on Plug (COP)
The ignition coil D has failed internally or lost electrical continuity. This is the most common cause and requires coil replacement.
- 2
Wiring or Connector Issues
Loose, corroded, or damaged connectors at the coil, broken connector locks, or damaged wiring in the coil driver circuit preventing signal transmission.
- 3
Short to Voltage or Ground
The COP driver circuit has shorted to battery voltage or ground, disrupting the ignition signal to coil D.
- 4
Faulty Powertrain Control Module
The PCM ignition driver circuit for coil D has malfunctioned, though this is rare without multiple coil codes present.
How to Diagnose It
- 1
Check Defective Coil on Plug (COP) — The ignition coil D has failed internally or lost electrical continuity. This is the most common cause and requires coil replacement.
- 2
Check Wiring or Connector Issues — Loose, corroded, or damaged connectors at the coil, broken connector locks, or damaged wiring in the coil driver circuit preventing signal transmission.
- 3
Check Short to Voltage or Ground — The COP driver circuit has shorted to battery voltage or ground, disrupting the ignition signal to coil D.
- 4
Check Faulty Powertrain Control Module — The PCM ignition driver circuit for coil D has malfunctioned, though this is rare without multiple coil codes present.
How to Fix It
- 1
Replace Ignition Coil D
Remove the connector and mounting bolt from coil D, then install a new OEM or quality aftermarket coil on plug unit. Verify coil seating on the spark plug well.
- 2
Inspect and Repair Connectors and Wiring
Check the coil connector for corrosion, bent pins, or loose terminals. Clean or replace the connector as needed. Inspect the wiring harness for damage or cuts and repair or replace if compromised.
- 3
Test Coil Driver Circuit
Using a multimeter, test the coil driver circuit for continuity and proper resistance. Check for shorts to ground or voltage on the PCM control line. If circuit is shorted, locate and repair the wiring fault.
- 4
Replace Powertrain Control Module
If wiring and coil test normal but the code persists, the PCM may have a failed ignition driver output. This requires PCM replacement and reprogramming, typically by a dealer.
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