1) Turn the ignition switch to ON.
2) Measure the voltage between accelerator pedal position sensor connector and chassis ground.
Connector & terminal
(B315) No. 4 (+) — Chassis ground (−):
Is the voltage 4.5 — 5.5 V?
Repair the short circuit of harness between ECM connector and accelerator pedal position sensor connector. Replace the ECM if defective.