How to read this pinout
We've grouped the pins by function because that's how most people look for them: "where's injector 3?" rather than "what's pin 21?". Wire colors are written out in full: the first color is the main wire color and the second is the stripe. Pins marked default come preset for that job, but you can reassign them in ESP.
Power, grounds and CAN
| Pin | Wire | Function |
|---|---|---|
| 26 | Red / blue | +13.8V supply to ECU and injectors |
| 10 | Black | Battery ground |
| 11 | Black / white | Sensor signal ground |
| 9 | Orange | +5V sensor supply |
| 16 | White | CAN high |
| 17 | Blue | CAN low |
Injectors and ignition
| Channel | Injector pin (wire) | Ignition pin (wire) |
|---|---|---|
| 1 | 19 (blue) | 3 (yellow / black) |
| 2 | 20 (blue / black) | 4 (yellow / red) |
| 3 | 21 (blue / brown) | 5 (yellow / orange) |
| 4 | 22 (blue / red) | 6 (yellow / green) |
| 5 | 27 (blue / orange) | 7 (yellow / brown) |
| 6 | 28 (blue / yellow) | 8 (yellow / blue) |
Digital pulsed outputs (DPO)
| Output | Pin | Wire |
|---|---|---|
| DPO 1 | 18 | Violet / black |
| DPO 2 | 1 | Violet / brown |
| DPO 3 | 23 | Violet / red |
| DPO 4 | 25 | Violet / orange |
| DPO 5 (default: fuel pump relay) | 24 | Black / yellow |
Sensor and switch inputs
| Input | Pin | Wire |
|---|---|---|
| Throttle position | 14 | White |
| Coolant temperature | 30 | Violet |
| Air temperature | 29 | Grey |
| AVI 1 (default: O2 sensor), shielded | 2 | Grey / yellow |
| AVI 3 (default: external MAP) | 15 | Yellow |
| DPI 1, shielded | 12 | Grey |
| DPI 2, shielded | 13 | Grey / black |
Trigger and Home
| Signal | Pin | Wire (inside which 4-core cable) |
|---|---|---|
| Trigger + | 31 | Yellow, in the grey 4-core |
| Trigger - | 33 | Green, in the grey 4-core |
| Home + | 32 | Yellow, in the grey/black 4-core |
| Home - | 34 | Green, in the grey/black 4-core |
Several pins share a plain color: pin 14 (throttle) and pin 16 (CAN high) are both white, and pin 17 (CAN low) and pin 19 (injector 1) are both blue. Check the pin number, not just the color, before you cut anything.
For full harness drawings, see the Elite 750 basic harness diagram and premium harness diagram. The Elite 750 overview covers the ECU's features, and the Elite 550 pinout is there if you're working on the smaller model. The ECU itself is here: Haltech Elite 750.
