Support reference
Trouble Shooting Guide
A practical starting point for diagnosing Lexus and Toyota V8 swap wiring, ECU, immobilizer, and startup issues.
Start with the basics
Power and grounds
Confirm battery voltage, ignition feeds, ECU powers, relay control, and all engine/ECU grounds before chasing deeper faults.
ECU and immobilizer
Confirm the ECU part number, immobilizer status, key/security hardware, and whether standalone operation has been prepared.
Communication and codes
If supported, check OBD2 communication and diagnostic codes before changing wiring or parts.
Information to collect
Photos
ECU label, fuse/relay setup, harness plugs, and any modified wiring areas.
Symptoms
No crank, no start, no spark, no injector pulse, no OBD communication, or intermittent running.
Project details
Engine, ECU, transmission, chassis, immobilizer plan, and what has already been tested.
Stuck on a wiring issue?
Send the symptoms, ECU label, wiring photos, and what has already been tested so support can start from useful evidence.