Code No. P0350: Ignition Coil Primary Circuit Malfunction <EURO2>

The battery voltage is applied to the ignition coil connector terminal from the engine control relay connector terminal and is earthed to the vehicle body from the ignition coil connector terminal.
A power voltage of 12 V is applied to the ignition coil connector terminal from the engine-ECU connector terminal CIL1, CIL2, CIL3 and CIL4.

When the engine-ECU turn the power transistor in the unit to OFF, the battery voltage is applied to the power transistor in the ignition coil, resulting that the power transistor is ON. And, when the engine-ECU turns the power transistor in the unit to ON, the power transistor in the ignition coil will be turned OFF.
When the power transistor in the ignition coil is turned to ON with any signal from the engine-ECU, the primary voltage will be applied through the ignition coil. When the power transistor in the ignition coil is turned OFF, the primary current is blocked and high voltage is generated in the secondary coil.

Check Condition

Judgement Criteria

The determination signal for the open circuit is continuously output from the confirmation signal circuit for the ignition built in the engine-ECU.

Failed ignition coil
Open/short circuit or harness damage in ignition system circuit or loose connector contact
Failed engine-ECU

DIAGNOSIS PROCEDURE

Ignition coil connector check.
Check ignition coil itself (Refer to GROUP 16 - Ignition System - On-vehicle Service - Ignition Coil Check ).

	Go to Step 2.

	Repair or replace the connector, or replace the ignition coil.

OK: Continuity (2 Ω or less)

	Go to Step 3.

	Check and repair harness between ignition coil connector terminal earth line and body earth. Check earthing line for open circuit and damage.

Check harness between ignition coil connector terminal and engine-ECU connector terminal CIL1 <No.1 cylinder>.
Check and repair harness between ignition coil connector terminal and engine-ECU connector terminal CIL2 <No.2 cylinder>.
Check and repair harness between ignition coil connector terminal and engine-ECU connector terminal CIL3 <No.3 cylinder>.
Check and repair harness between ignition coil connector terminal and engine-ECU connector terminal CIL4 <No.4 cylinder>.

	Go to Step 4.

	Repair the connector(s) or wiring harness.

	Replace the engine-ECU.

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).