Diagnostic Aids

WARNING: This page is about a different car, the 2003 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.

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 1/2 is 8.1 kHz. If oscilloscope is available, knock sensor 1/2 operation may be checked by reading knock sensor waveform patterns with engine at 4000 RPM. Knock sensor waveform patterns may be checked by connecting oscilloscope between body ground and ECM 35-pin connector E5 terminal No. 1 (KNK1) (Black wire) and at ECM 35-pin connector E5 terminal No. 2 (KNK2) (White wire). ECM is located behind glove box. See Figure. For ECM electrical connector terminal identification, see Figure. Spread the time on the horizontal axis and confirm that period of the wave is 0.123 m/sec. (Normal mode vibration frequency of knock sensor: 8.1 kHz). See Figure. If the normal mode vibration frequency is not 8.1 kHz, the sensor is malfunctioning.