Possible causes

– Faulty Ignition Coil 4
– Ignition Coil 4 harness is open or shorted
– Ignition Coil 4 circuit poor electrical connection
– Faulty Engine Control Module (ECM)

When is the code detected?

Each ignition circuit is continuously monitored by the Engine Control Module (ECM). The test fails when the ECM does not receive a valid pulse signal from the ignition coil.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Lack/Loss of Power
– Engine may be harder to start
– Engine hesitation
– Rough engine idle

P0354 LEXUS Description

The ignition system on the vehicle uses individual ignition coils for each cylinder. The Engine Control Module (ECM) controls each ignition coil operation. The ECM sends a ON/OFF signal to energize the ignition coil to create a spark at the spark plug when a spark is required at the cylinder.

LEXUS Technical Service Bulletins for P0354 code