1) Connect the connector to ECM.
2) Measure the resistance between accelerator pedal position sensor connector and chassis ground.
Connector & terminal
(B315) No. 3 — Chassis ground:
Is the resistance 1 MΩ or more?
Replace the accelerator pedal.
Repair the short circuit to ground in harness between ECM and accelerator pedal position sensor connector. Replace the ECM if defective.