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; DTC P0355 Ignition Coil "E" Primary / Secondary Circuit; DTC P0356 Ignition Coil "F" Primary / Secondary Circuit; DTC P0357 Ignition Coil "G" Primary / Secondary Circuit; DTC P0358 Ignition Coil "H" Primary / Secondary Circuit: Description

HINT.

• These DTCs indicate malfunctions relating to the primary circuit
• If DTC P0351 is set, check the No. 1 ignition coil circuit
• If DTC P0352 is set, check the No 2 ignition coil circuit.
• If DTC P0353 is set, check the No. 3 ignition coil circuit.
• If DTC P0354 is set, check the No 4 ignition coil circuit
• If DTC P0355 is set, check the No. 5 ignition coil circuit
• If DTC P0356 is set, check the No 6 ignition coil circuit
• If DTC P0357 is set, check the No 7 ignition coil circuit
• If DTC P0358 is set, check the No 8 ignition coil circuit

A direct ignition system is used on this vehicle

The direct ignition system is a ignition system in which each cylinder is ignited by one ignition coil and 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 sparks of the spark plugs pass from the center electrode to the ground electrodes

The ECM determines the ignition timing and transmits the ignition signals (IGT) 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 signal (IGF) to the ECM, for each cylinder ignition

Fig 1: Ignition Coil Primary/Secondary Circuit Diagram

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Reference Inspection using an oscilloscope

Fig 2: Identifying IGT And IGF Signal Waveform

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

While cranking or idling the engine, check the waveform between terminals IGT (1 to 8) and E1, and IGF1, IGF2 and E1 of the ECM connectors

HINT:

The wavelength becomes shorter as the engine speed increases.