DTC P0351 Ignition Coil "A" Primary/Secondary Circuit; DTC P0352 Ignition Coil "B" Primary/Secondary Circuit; DTC P0353 Ignition Coil "C" Primary/Secondary Circuit; DTC P0354 Ignition Coil "D" Primary/Secondary Circuit: Description

HINT:

• These DTCs indicate malfunctions relating to the primary circuit.
• If DTC P0351 is output, check the No. 1 ignition coil circuit.
• If DTC P0352 is output, check the No. 2 ignition coil circuit.
• If DTC P0353 is output, check the No. 3 ignition coil circuit.
• If DTC P0354 is output, check the No. 4 ignition coil circuit.

A Direct Ignition System (DIS) is used on this vehicle.

The DIS is a 1-cylinder ignition system in which each cylinder is ignited by one ignition coil and one spark plug is connected to the end of each secondary wiring. A powerful voltage, generated in the secondary wiring, is applied directly to each spark plug. The spark of the spark plugs passes from the center electrode to the ground electrodes.

The ECM determines the ignition timing and transmits the ignition (IGT) signals to each cylinder. Using the IGT signal, the ECM turns the power transistor inside the igniter on and off. The power transistor, in turn, switches on and off the current to the primary coil. When the current to the primary coil is cut off, a powerful voltage is generated in the secondary coil. This voltage is applied to the spark plugs, causing them to spark inside the cylinders. As the ECM cuts the current to the primary coil, the igniter sends back an ignition confirmation (IGF) signal to the ECM for each cylinder ignition.

Fig 1: Ignition Coil Communication Diagram

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Identifying Signal Waveform

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Reference: Inspection using an oscilloscope.

While cranking or idling the engine, check the waveform between terminals IGT (1 to 4) and E1, and IGF1 and E1 of the ECM connector.