Toyota 1 MZ–FE Manual page 499

DTC P0325 P0330 Knock Sensor Circuit Malfunction
(Knock Sensor 1 Knock Sensor 2)
CIRCUIT DESCRIPTION
Knock sensors are fitted one each to the right bank and left bank of the cylinder block to detect engine
knocking. This sensor contains a piezoelectric element which generates a voltage when it becomes
deformed, which occurs when the cylinder block vibrates due to knocking. If engine knocking occurs,
ignition timing is retarded to suppress it.
Diagnostic Trouble Code Detecting Condition
DTC No.
No knock sensor 1 signal to ECM with engine
P0325
speed 2,000 rpm or more.
No knock sensor 2 signal to ECM with engine
P0330
speed 2,000 rpm or more.
If the ECM detects the above diagnosis conditions, it operates the fail safe function in which the corrective
retard angle value is set to the maximum value.
WIRING DIAGRAM
1MZ–FE ENGINE – CIRCUIT INSPECTION
Open or short in knock sensor 1 circuit.
Knock sensor 1 (looseness).
ECM
Open or short in knock sensor 2 circuit.
Knock sensor 2 (looseness).
ECM
Trouble Area
EG2–499