ECU spec · Holley

Holley Terminator X pinout and specs

Holley Terminator X is a 60-pin wire-in Holley ECU on 2 connectors: J1A (34 pins) and J1B (26 pins).

It has 8 injector outputs and 8 ignition outputs. The injector drivers are saturated, which means high-impedance injectors. Low-impedance ones need a ballast resistor pack or a different ECU. The ignition outputs are logic-level. Smart coils plug straight in; dumb coils need an igniter in between.

There are 2 dedicated trigger inputs, each happy with a VR or a Hall sensor. Two knock inputs cover both banks of a V engine. It has an onboard wideband controller, so a sensor wires straight in. The MAP sensor is built in.

It does not drive an electronic throttle, so plan on a cable throttle. One CAN bus handles dashes, PDMs and expansion. Three outputs can switch 12V as well as ground.

Spec sheet

ConnectorsJ1A (34), J1B (26)60 pins in this profile
Injector outputs8saturated (high-impedance only)
Ignition outputs8logic-level: smart coils, or an igniter for dumb coils
Dedicated trigger inputs2VR or Hall
Knock inputs2
Onboard wideband controllers1
Onboard MAP sensorYes
CAN buses1
Drive-by-wireNo
High-side outputs3
Half-bridge outputs4H-bridge pairs for a throttle motor or stepper
5V sensor supply1 pin

Worth knowing

  • Holley's diagram and product page disagree on whether outputs 1 and 2 switch 12V or ground.

Which builds it suits

Of the 58 swap presets in the planner, 0 fit as they are and 27 fit with add-ons; 31 do not fit at all. The add-on it asks for most often is the Holley Pro Dash (with I/O). Where it falls short, it is usually not enough drive-by-wire throttle motor (h-bridge). The planner fills anything a preset leaves open with its ordinary defaults, so your own build may land differently.

The Toyota 2JZ-GTE non-VVTi needs Holley Pro Dash (with I/O) and an external igniter. The Nissan SR20DET (S13) needs Holley Pro Dash (with I/O) and an external igniter. It can't run the GM LS LY6/L96 (Gen4 6.0 iron): not enough drive-by-wire throttle motor (h-bridge). It can't run the Ford Barra 4.0 Turbo (240T/245T/270T/310T/325T): not enough drive-by-wire throttle motor (h-bridge). It can't run the Mazda Rotary 13B-MSP Renesis (RX-8 manual, 6-injector): not enough drive-by-wire throttle motor (h-bridge).

Fits with add-ons 27
Does not fit 31

Plan a build around the Holley Terminator X

Pin table

By connector: J1A carries 2 trigger inputs, 2 knock inputs and 10 analog inputs; J1B carries 8 injector outputs, 8 ignition outputs and 4 H-bridge outputs.

Show all 60 pins
PinFunction
J1A A1Coil -
J1A A2Fuel pump relay out (10A max)
J1A A3Input #2 (F,5,2,T,H,G)
J1A A4Input #4 (F,G,5)
J1A A5TPS signal
J1A A6Points output
J1A A7WBI_COMPR2
J1A A8WBI shield
J1A A9WBI HTR-
J1A A10Switched +12V in
J1A A11MAT input
J1A A12Input #1 (F,5,2,T,H,G)
J1A A13Input #3 (F,G,5)
J1A A14IPU ground
J1A A15Gauge output
J1A A16WBI_COMPR1
J1A A17WBI VS-/IP-
J1A A18Sensor ground out
J1A A19Coolant temp in
J1A A20Oil pressure
J1A A21Knock #2 in
J1A A22Cam input (DIG & IPU)/bypass
J1A A23MAP sensor signal
J1A A24CAN LO
J1A A25WBI VS+
J1A A26Sensor +5V ref out
J1A A27Not used
J1A A28EST/SPOUT out
J1A A29Knock #1 input
J1A A30Crank input (DIG & IPU)
J1A A31Fuel pressure
J1A A32CAN HI
J1A A33WBI IP+
J1A A34WBI HTR+
J1B B1IAC A LO
J1B B2IAC A HI
J1B B3PWM #4 out (G,P-)
J1B B4Injector F
J1B B5Injector G
J1B B6Injector H
J1B B7Injector E
J1B B8IAC B LO
J1B B9IAC B HI
J1B B10PWM #3 out (G,P-)
J1B B11PWM #2 out (H,P+)
J1B B12PWM #1 out (H,P+)
J1B B13Injector D
J1B B14EST ground out
J1B B15EST 2 (cylinder #2)
J1B B16EST 4 (cylinder #4)
J1B B17EST 6 (cylinder #6)
J1B B18EST 8 (cylinder #8)
J1B B19Injector A
J1B B20EST 12V out
J1B B21EST 1 (cylinder #1)
J1B B22EST 3 (cylinder #3)
J1B B23EST 5 (cylinder #5)
J1B B24EST 7 (cylinder #7)
J1B B25Injector C
J1B B26Injector B

Other Holley ECUs

The closest Holley unit is the Holley HP EFI. Against it, this one has saturated injector drive (the HP EFI is peak-and-hold).

Source: Holley document Terminator X and X Max Manual

Always verify against the manufacturer's manual and your tuner before wiring.