| CAUTION | If Engine Control Module (ECM) replacement is instructed in following test, always ensure ECM electrical connectors and ground circuits are okay. If either are defective, repair and repeat testing to confirm ECM malfunction. |
Circuit Description
Knock sensor No. 2 generates voltage when engine block vibrates due to knocking. DTC is set when ECM does not receive input signal from knock sensor No. 2 with engine speed of 1500-6000 RPM. If DTC P0330 exists, ECM will operate in fail-safe mode which retards the ignition timing to a maximum setting. Possible causes are
- Knock sensor No. 2 circuit is open or shorted.
- Defective or loose knock sensor No. 2.
- Defective ECM.
Diagnostic Aids
Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.
Normal mode vibration frequency of knock sensor is 8.1 kHz. If oscilloscope is available, knock sensor No. 2 operation may be checked by reading knock sensor signal waveform patterns with engine at 4000 RPM. Knock sensor waveform patterns may be checked by connecting oscilloscope between body ground and terminal No. 17 (Black wire) at ECM electrical connector E7. This is the KNKR terminal on ECM. ECM is located behind glove box and heater duct. (Схема №2) For ECM electrical connector terminal identification (Схема №4) Knock sensor waveform patterns should be properly displayed. (Схема №10)