What lives on the 26-pin plug
Think of the Elite 2000's 26-pin connector as the "sensing" half of the ECU. Most of what is on it reads the engine: crank and cam position, air and coolant temperature, oxygen sensors, knock and speed-type signals. It also carries the main 12 V feed to the ECU and the CAN bus. The injector and most output wiring lives on the other plug, covered in the 34-pin main connector pinout.
Wire colors below are Haltech's harness abbreviations: B black, W white, R red, G green, L blue, Y yellow, O orange, V violet, GY grey, BR brown. "SHD" means the wire is shielded, and that shield should stay intact all the way to the sensor end.
Pin-by-pin table
| Pin | Wire color | Function | Notes |
|---|---|---|---|
| 1 | Y (SHD) | Crank (Trigger) + | Digital (Hall/optical) or reluctor sensors |
| 2 | Y (SHD) | Cam (Home) + | Digital (Hall/optical) or reluctor sensors |
| 3 | GY | AVI 7, air temp | 0 to 5 V input, 1k pull-up switchable in software |
| 4 | V | AVI 8, coolant temp | 0 to 5 V input, 1k pull-up switchable in software |
| 5 | G (SHD) | Crank (Trigger) - | Reference for reluctor sensors |
| 6 | G (SHD) | Cam (Home) - | Reference for reluctor sensors |
| 7 | GY/R (SHD) | SPI 4 | Up to 50 kHz, 25 V DC maximum |
| 8 | GY (SHD) | SPI 1 | Up to 50 kHz, 25 V DC maximum |
| 9 | GY/B (SHD) | SPI 2 | Up to 50 kHz, 25 V DC maximum |
| 10 | GY/BR (SHD) | SPI 3 | Up to 50 kHz, 25 V DC maximum |
| 11 | R/W | +13.8 V ECU supply | Main 12 V power into the ECU |
| 12 | GY/O (SHD) | AVI 6, O2 input 1 | 0 to 5 V input, narrowband O2 compatible |
| 13 | GY/Y (SHD) | AVI 1, O2 input 2 | 0 to 5 V input, narrowband O2 compatible |
| 14 | B/W | Signal ground | Sensor ground |
| 15 | B/W | Signal ground | Sensor ground |
| 16 | B/W | Signal ground | Sensor ground |
| 17 | Y/V | IGN 7 | 1 A maximum |
| 18 | Y/GY | IGN 8 | 1 A maximum |
| 19 | V/O | DPO 4 | Switches to ground, 1 A maximum, fixed 12 V pull-up |
| 20 | O/G | AVI 5 | 0 to 5 V input, 1k pull-up switchable in software |
| 21 | GY/G | Knock 1 | Piezoelectric knock sensors |
| 22 | GY/L | Knock 2 | Piezoelectric knock sensors |
| 23 | W | CAN H | CAN high |
| 24 | L | CAN L | CAN low |
| 25 | - | Not used | |
| 26 | - | Not used |
Wiring notes by group
Crank and cam (pins 1, 2, 5, 6)
Both inputs accept either a digital sensor or a two-wire reluctor. With a reluctor, the negative pin (5 or 6) is the sensor's return. With a Hall or optical sensor, only the positive pin carries the signal; power and ground for the sensor come from elsewhere. Keep these shielded wires well away from ignition leads and coils. See trigger wiring for the details.
Temperature inputs (pins 3 and 4)
Two-wire temperature sensors need the 1k pull-up turned on in ESP. Without it, the reading will sit pinned at one end of the scale. The other side of each sensor goes to a signal ground on pins 14 to 16.
SPIs (pins 7 to 10)
These measure frequency and duty, which makes them the right home for wheel speed, driveshaft speed and flex fuel sensors. Mind the 25 V DC limit if you're feeding them from something that can spike.
O2 inputs (pins 12 and 13)
These can read a narrowband sensor directly. A wideband needs a controller, and on most builds we use a CAN wideband over pins 23 and 24 instead. See exhaust gas oxygen sensors.
Knock (pins 21 and 22)
Knock sensor signals are tiny, so route them away from injector and ignition wiring. The knock sensor wiring page has the rest.
Outputs (pins 17 to 19)
IGN 7 and 8 and DPO 4 are all limited to 1 A. That's plenty to trigger a relay or an igniter input, but never enough to run a solenoid or pump directly.
Power, ground and CAN
Pin 11 is the ECU's 12 V supply and should come from a properly fused, switched feed. Signal grounds (14 to 16) are for sensors only. Don't use them to ground loads. CAN H and CAN L should be twisted together.
Related Elite 2000 pages
Start at the Elite 2000 overview, or see how the universal harness breaks this plug out in the 26-pin harness guide. If you're checking a harness that won't behave, send us the details.
