I’ve bought 16 new modules and replaced as many as I can all volts are good but still have the triangle of death. I’ve bought a scanner and it shows Block 1 at -25 and blocks 3,4,5 reading 0 volts. I’m reading them right to left. I swapped the cells around to narrow it down and I’m still getting same voltage on same blocks. Is it the harness or ECU?
High probability it is the harness and not the ECU. But check the pins of the orange plug in the ECU, to be sure. If it is the harness, buy a new WIRE, FRAME, NO.2 (PNC 82165C) Part Number 82165-47040 from your local or online Toyota parts dept. It will be the best $70 you spent.
Block voltages coming out negative are usually telltale signs of damage to that harness or to the pins of the connector where it plugs into the ECU.