Circuit Description

If the low octane fuel or the bad fuel is used, engine knocking will occur. The knock sensor is used to monitor whether the knocking is occurring or not and its signal is sent to ECM. Two knock sensors are located on the engine block between the left bank and the right bank (one sensor is on the each bank) When ECM detects the knocking based on the knock signal from the sensor, ECM makes spark retard until the knock disappears.