OBD2 Diagnostics Wiring for 2JZ-GTE VVTi JZS161 Aristo Swap

Electricalintermediate✓ Community Verified

Problem

After swapping a 2JZ-GTE VVTi (JZS161 Aristo) engine into a MK3 Supra, the OBD diagnostic connector was cut and standard US OBD2 scanners would not communicate with the ECU, which uses a Japanese OBD protocol (JOBD) incompatible with standard US scan tools.

No OBD diagnostic communication with swapped 2JZ-GTE VVTi engineStandard US OBD2 scanners fail to connect to ECUOBD connector wiring cut or missing after engine swap

Root Cause

The JZS161 Aristo 2JZ-GTE VVTi ECU uses a Japanese OBD protocol (JOBD) that requires specific wiring to the OBD2 connector and a custom communication protocol initialization sequence, not the standard US OBD2 protocol.

Confidence

Moderate confidence — Multiple community members agreed on this solution

View Original Thread →Posted September 2019 on SupraForums.com