Holley Terminator X pinout
ecurecovery.com/pinouts/holley/terminator-x · Every pin checked against 2 Holley documents · data checked 2026-11-04
Holley Terminator X pinout
Every pin of the 34-pin J1A and 26-pin J1B connectors, with Holley's own pin names. Tap a pin to see what it does.
Every pin checked against 2 Holley documents- Connector J1A · 34-pin
- Connector J1B · 26-pin
Holley's documents list the pins but do not draw the plug, so we do not draw it either.
Pick any pin in the table to see its function and the documents it was checked in.
Holley Terminator X connector J1A pinout (34-pin)
| Pin | Function |
|---|---|
| A1 | Coil - Input |
| A2 | Fuel Pump Out (+12v) (10A Max) |
| A3 | Input #2 (F52THG) |
| A4 | Input #4 (F5G) |
| A5 | TPS Input |
| A6 | Points Trigger Output |
| A7 | WB1 COMPR2 |
| A8 | WB1 Shield |
| A9 | WB HTR - |
| A10 | Switched +12v Input |
| A11 | Manifold Air Temp Input |
| A12 | Input #1 (F52THG) |
| A13 | Input #3 (F5G) |
| A14 | Cam/Crank Ground |
| A15 | Gauge Digital Output |
| A16 | WB1 COMPR1 |
| A17 | WB1 VS-/IP+ |
| A18 | Sensor Ground |
| A19 | Engine Coolant Temp Input |
| A20 | Oil Pressure Input |
| A21 | Knock #2 Input |
| A22 | Cam Sync Input / Ignition Bypass Output |
| A23 | Map Sensor Input |
| A24 | CAN Lo |
| A25 | WB1 VS+ |
| A26 | Sensor +5v |
| A27 | Not used |
| A28 | EST/Spout Output |
| A29 | Knock #1 Input |
| A30 | Crank Speed Input |
| A31 | Fuel Pressure Input |
| A32 | CAN Hi |
| A33 | WB1 IP+ |
| A34 | WB HTR + |
Holley Terminator X connector J1B pinout (26-pin)
| Pin | Function |
|---|---|
| B1 | IAC A Lo |
| B2 | IAC A Hi |
| B3 | Output #4 (G P-) |
| B4 | Injector F Output |
| B5 | Injector G Output |
| B6 | Injector H Output |
| B7 | Injector E Output |
| B8 | IAC B Lo |
| B9 | IAC B Hi |
| B10 | Output #3 (G P-) |
| B11 | Output #2 (G P-) |
| B12 | Output #1 (G P-) |
| B13 | Injector D Output |
| B14 | EST Ground Output |
| B15 | EST 2 Output (Cylinder #2) |
| B16 | EST 4 Output (Cylinder #4) |
| B17 | EST 6 Output (Cylinder #6) |
| B18 | EST 8 Output (Cylinder #8) |
| B19 | Injector A Output |
| B20 | EST 12V Output |
| B21 | EST 1 Output (Cylinder #1) |
| B22 | EST 3 Output (Cylinder #3) |
| B23 | EST 5 Output (Cylinder #5) |
| B24 | EST 7 Output (Cylinder #7) |
| B25 | Injector C Output |
| B26 | Injector B Output |
Holley Terminator X pins at a glance
- Which pins are CAN on the Holley Terminator X?
- CAN Lo: pin A24. CAN Hi: pin A32.
- Which pins are the crank and cam inputs on the Holley Terminator X?
- Coil - Input: pin A1. Cam/Crank Ground: pin A14. Cam Sync Input / Ignition Bypass Output: pin A22. Crank Speed Input: pin A30.
- Which pins are the injector outputs on the Holley Terminator X?
- Injector F Output: pin B4. Injector G Output: pin B5. Injector H Output: pin B6. Injector E Output: pin B7. Injector D Output: pin B13. Injector A Output: pin B19. Injector C Output: pin B25. Injector B Output: pin B26.
- Which pins are the ignition outputs on the Holley Terminator X?
- EST/Spout Output: pin A28. EST 2 Output (Cylinder #2): pin B15. EST 4 Output (Cylinder #4): pin B16. EST 6 Output (Cylinder #6): pin B17. EST 8 Output (Cylinder #8): pin B18. EST 1 Output (Cylinder #1): pin B21. EST 3 Output (Cylinder #3): pin B22. EST 5 Output (Cylinder #5): pin B23. EST 7 Output (Cylinder #7): pin B24.
- Which pins are ground on the Holley Terminator X?
- Sensor Ground: pin A18.
- Which pins power the Holley Terminator X?
- Switched +12v Input: pin A10.
- Which pins are the sensor supplies on the Holley Terminator X?
- Sensor +5v: pin A26.
- Which pins are the wideband sensor connections on the Holley Terminator X?
- WB1 COMPR2: pin A7. WB1 Shield: pin A8. WB HTR -: pin A9. WB1 COMPR1: pin A16. WB1 VS-/IP+: pin A17. WB1 VS+: pin A25. WB1 IP+: pin A33. WB HTR +: pin A34.
Holley Terminator X pinout sheet
A printable sheet with every pin, made from the checked data on this page.
Where this comes from
Only Holley's own documents. Pin names and notes are written exactly as Holley writes them.
Holley 199R10837 EFI harness kit sheet (ECU pinout)
Holley 558-400 auxiliary harness sheet (input / output types)
Holley 199R10555 wiring manual (HP EFI and Dominator EFI) (written for the HP EFI / Dominator: the same pins)
How we checked it
- We start from Holley's J1A / J1B pin list for this ECU.
- Every pin is read again in a second Holley document: the HP / Dominator wiring manual and the EFI harness kit sheet, which lists the same J1A / J1B pins for the HP, Dominator, Terminator X and X Max. A script compares them pin by pin.
- A pin is only shown when both documents give the same function. Where Holley marks a pin as different on one ECU, that ECU's own entry is used and checked against the 558-400 harness sheet. Holley's pin lists give no wire colours and draw no plug, so none are shown.
- Labels are Holley's own words, as printed in its pin list.
Where Holley's documents disagree
A3: Holley's 558-400 auxiliary harness sheet lists this Terminator X input as configurable F 5 H G; the J1A / J1B pinout (199R10837), shared with the HP and Dominator, lists the letters shown in the label. Shown: the pinout's label.
A4: Holley's 558-400 auxiliary harness sheet lists this Terminator X input as configurable F 5 H G; the J1A / J1B pinout (199R10837), shared with the HP and Dominator, lists the letters shown in the label. Shown: the pinout's label.
A12: Holley's 558-400 auxiliary harness sheet lists this Terminator X input as configurable F 5 H G; the J1A / J1B pinout (199R10837), shared with the HP and Dominator, lists the letters shown in the label. Shown: the pinout's label.
A13: Holley's 558-400 auxiliary harness sheet lists this Terminator X input as configurable F 5 H G; the J1A / J1B pinout (199R10837), shared with the HP and Dominator, lists the letters shown in the label. Shown: the pinout's label.
ECU Recovery is not affiliated with Holley. Holley and its product names are trademarks of Holley. If your harness came with its own diagram, check your wiring against it.
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