The ECM constantly generates a 5 V power source voltage from the battery voltage supplied to the +B (BATT) terminal to operate the microprocessor. The ECM also provides this power source voltage to the sensors through the VC output circuit.

When the engine switch is turned on (IG), the battery voltage is applied to the IGSW terminal of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the coil of the No. 1 integration relay (EFI relay), closing the contacts and supplying power to terminals +B and +B2 of the ECM.

Refer to DTC P2195 ().

The soak timer operates after the engine switch is turned off. When a certain amount of time has elapsed after turning the engine switch off, the soak timer activates the ECM to perform malfunction checks which can only be performed after the engine is stopped. The soak timer is built into the ECM.

Refer to P0412 ().

Refer to DTC P0412 ().

The intake camshaft VVT sensor (VV1 and VV2 signal) consists of a magnet and MRE (Magnetoresistive Element).

Refer to DTC P0412 ().

Refer to DTC P0416 ().

If there is no signal from the crankshaft position sensor despite the crankshaft revolving, the ECM interprets this as a malfunction of the sensor.

When the sensor output voltage remains at below 0.3 V, or higher than 4.7 V for more than 4 seconds, the ECM stores a DTC.

A flat-type knock sensor (non-resonant type) has a structure that can detect vibrations between approximately 5 kHz and 15 kHz.

Knock sensors are fitted onto the engine block to detect engine knocking.

Each knock sensor contains a piezoelectric element which generates a voltage when it becomes deformed.