CHECK INPUT SIGNAL OF ECM.

1) Connect the connectors to ECM and knock sensor.

2) Turn the ignition switch to ON.

3) Measure the voltage between ECM and chassis ground.

Connector & terminal

(B134) No. 15 (+) — Chassis ground (−):

QUESTION
Is the voltage 2 V or more?
Yes	No
Even if the malfunction indicator light illuminates, the circuit has returned to a normal condition at this time. (However, the possibility of poor contact still remains.) NOTE: In this case, repair the following item: • Poor contact of knock sensor connector • Poor contact in ECM connector • Poor contact of coupling connector	Repair the poor contact of ECM connector.