1) Disconnect the ID code box connector and the ECM connector.
2) Using a tester, measure the resistance between ID code box connector and ECM.
Connector & terminal
(B422) No. 6 — (B135) No. 23:
Is the resistance less than 10 Ω?
Replace the ID code box.
Repair or replace the harness (B422) No. 6 line between ID code box and ECM.