7MGTE Swap Engine Harness Plug Identification - Wiring Diagram Reference

Electricaladvanced✓ OP Confirmed

Problem

After swapping a 1991 7MGTE into a 1987 NA Supra, the owner could not remember where the engine harness connectors plug into the various engine sensors. The later-generation engine harness is not plug-and-play with the earlier Gen 1 (yellow plug) chassis.

Multiple unconnected engine harness plugs after 7MGTE swapUnable to identify connector destinations for engine sensorsGen 2 (grey plug) engine harness adapted to Gen 1 (yellow plug) chassis on interior side but under-hood connections unknown

Root Cause

The 1991 7MGTE engine wire harness and ECU are a second-generation design that does not directly match the first-generation 1987 chassis wiring. Each engine sensor (TPS, igniter, idle air control, etc.) has a unique connector, but without a reference diagram the locations are not obvious, especially with aftermarket modifications like a front-facing intake manifold, AEM V1 standalone ECU, and Q45 throttle body.

Confidence

Low confidence — Original poster confirmed this resolved the issue

View Original Thread →Posted March 2020 on SupraForums.com