The Toyota 1KZ-TE is one of the most beloved diesel engines ever produced. Found in legendary vehicles like the Land Cruiser Prado (KZJ70, KZJ90), Hilux Surf, and Hiace van, this 3.0-liter turbo-diesel is known for its reliability—until an electrical gremlin appears.
What is the printed on your ECU sticker (e.g., 89661-3D240)?
Tom sat at his workbench, surrounded by wiring diagrams, ECU manuals, and a 1KZ-TE ECU he had salvaged from a junkyard. He cracked open a cold soda and began his journey to understand the mysterious world of ECU pinouts.
If your wiring checks out perfectly but you experience intermittent stalling, random check engine lights, or a total loss of communications, open your metal ECU casing. 1KZ-style ECUs from the 1990s suffer from aging electrolytic capacitors that leak corrosive fluid onto the circuit board traces. Replacing these capacitors can completely revive an erratic ECU without needing to rewire the vehicle. 1kz ecu pinout
Engine speed (RPM) sensor signals located inside the injection pump. Essential for calculating injection volume. Sensors & Inputs
Essential for cold starts and glow plug timing.
Check sensor grounds: Pin E2 should be 0V relative to battery negative. The Toyota 1KZ-TE is one of the most
Wiring a 1KZ-TE doesn't have to be a nightmare if you tackle it one plug at a time. Always verify your specific ECU part number, as there are slight variations between the Hilux (KZN165) and the Prado (KZJ95) pinouts, particularly regarding the air conditioning and automatic transmission shift points.
| Color | Abbr | Circuit | |-------|------|---------| | Black | B | Ground | | Black/White | B-W | ECU main relay power | | Red/Black | R-B | +B, +B1 | | Yellow/Black | Y-B | STA (starter) | | Green/Red | G-R | RSC (spill valve) | | Green/Black | G-B | TCV (timing valve) | | Blue/Red | L-R | FSV (fuel shutoff) | | White/Black | W-B | NE+ / NE- | | Brown | BR | THW (coolant temp) |
People often confuse the Spill Control Valve (SCV) and the Timing Control Valve (VCV). Tom sat at his workbench, surrounded by wiring
If the ECU loses the signal, the engine will cut out instantly.
| Pin(s) | Typical Signal Name | Function / Description | | :--- | :--- | :--- | | | | A15, A16, A32, A48 | +B / +B1 | Main power supply to the ECU from the battery and EFI relay. | | A31 | MREL | The ECU grounds this pin to energize the main injection relay (R09) when the ignition is on. | | A47 | +B (IG SW) | Switched 12V power from the ignition (key-on). | | B6, B54 | E1, E2 | Power grounds for the ECU. | | Sensors (Inputs) | | B10, B59 | NE+, NE- | RPM sensor (crank position). Sends a frequency signal to the ECU. These are low-intensity signals, so their wires are typically shielded. | | B42 | G2+ | Timing (camshaft) position sensor. Sends a frequency signal corresponding to cylinder phase. | | B25 | THW | Engine coolant temperature (ECT) sensor signal. Variable resistance based on temperature. | | A25 | VPA, VPA2 | Accelerator pedal position sensor (for electronic throttle) signals, varying between 0V and 5V depending on pedal position. | | B23 / B28 | OX1B / OX2B | Oxygen (lambda) sensor signals, indicating the air-fuel mixture for optimal combustion and efficiency. | | Actuators (Outputs) | | A30 | FC | Circuit opening relay for the fuel pump. The ECU grounds this pin to operate the relay and activate the pump. | | B22, B38 | KNK1, KNK2 | Knock sensor signals. Two separate sensors send data back to the ECU for detonation control. | | B34, B50, B2, B18 | HTR | Heater circuits for the lambda sensors. |