Always check the E2 (Sensor Ground) . A poor ground here will cause erratic idle and "Ghost" sensor codes. Conclusion
Ensure the SCV (Suction Control Valve) and the Fuel Rail Pressure sensor are pinned correctly.
If you have crank but no fire, check the VC (5V Reference) . If a sensor is shorted (like a crushed wire on the AC pressure switch), it can pull the 5V line to 0V, effectively "blinding" the ECU. toyota 2kdftv ecu pinout diagram best
The ECU must be connected to the EDU (Injector Driver). Without the "IJt" and "IJf" feedback signals between the ECU and EDU, the system will trigger a fail-safe mode. Pro-Tips for Troubleshooting
Engine grounds. E1 is usually the main chassis ground, while E2 is the sensor signal ground. 2. The Fuel System (The Core of the 2KD) Always check the E2 (Sensor Ground)
Fuel Rail Pressure Sensor signal. This is a 0.5V to 4.5V signal that tells the ECU how much pressure is in the rail.
OBD2 (K-Line or CAN) and the EDU trigger signals. Primary Pinout Functions (Common Denso 104-Pin/134-Pin) If you have crank but no fire, check the VC (5V Reference)
Crank/Cam positions, Rail Pressure, MAP (Turbo Boost), and Water Temp.
SCV (Suction Control Valve), EGR, and Turbo VNT (if applicable).
Immobilizer Input/Output. If you are doing an engine swap, the ECU will look for a "handshake" here. If it doesn't receive it, the injectors will remain locked. Wiring for Swaps: The "Standalone" Essentials