ECU spec · Haltech

Haltech Elite 550 pinout and specs

Haltech Elite 550 is a 29-pin wire-in Haltech ECU on 1 connector: 34pin (29 pins).

It has 4 injector outputs and 4 ignition outputs. The injector drivers are peak-and-hold, so low-impedance injectors run without a resistor pack. 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. There is no knock input. Wideband control needs an external controller, usually over CAN. 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.

Spec sheet

Connectors34pin (29)29 pins in this profile
Injector outputs4peak-and-hold (low-impedance capable)
Ignition outputs4logic-level: smart coils, or an igniter for dumb coils
Dedicated trigger inputs2VR or Hall
Knock inputs0
Onboard wideband controllers0
Onboard MAP sensorYes
CAN buses1
Drive-by-wireNo
High-side outputs0
Half-bridge outputs0
5V sensor supply1 pin

Worth knowing

  • CAN is for Haltech CAN devices only.
  • Internal MAP: Haltech's guide and website give different ranges; the page gives none.

Which builds it suits

Of the 58 swap presets in the planner, 0 fit as they are and 1 fits with add-ons; 57 do not fit at all. The add-on it asks for most often is the Haltech PD16 (Power Distribution Module). Where it falls short, it is usually not enough injector output (low-side). The planner fills anything a preset leaves open with its ordinary defaults, so your own build may land differently.

The Mazda Rotary 13B-REW (FD RX-7) needs Haltech PD16 (Power Distribution Module) and Haltech WB1 (single-channel CAN wideband). It can't run the Toyota 2JZ-GE distributor (NA, early): not enough injector output (low-side). It can't run the Ford Modular 4.6 4V Cobra (NA, cable): not enough injector output (low-side). It can't run the Nissan VQ35DE Rev-Up (2005-06): not enough injector output (low-side).

Fits with add-ons 1
Does not fit 57

Plan a build around the Haltech Elite 550

Pin table

Connector 34pin carries 4 injector outputs, 4 ignition outputs and 2 trigger inputs.

Show all 29 pins
PinFunction
34pin 1DPO 2 (low-side aux)
34pin 2AVI 1 (default O2 sensor)
34pin 3IGN 1 (logic-level ignition)
34pin 4IGN 2
34pin 5IGN 3
34pin 6IGN 4
34pin 9+5V DC sensor supply
34pin 10Battery ground
34pin 11Signal ground (sensor ref)
34pin 12DPI 1 (digital pulsed input)
34pin 14Throttle position sensor (AVI)
34pin 15AVI 3 (default MAP)
34pin 16CAN-H
34pin 17CAN-L
34pin 18DPO 1 (low-side aux)
34pin 19INJ 1 (injector drive)
34pin 20INJ 2
34pin 21INJ 3
34pin 22INJ 4
34pin 23DPO 3 (low-side aux)
34pin 24DPO 5 (default fuel-pump relay)
34pin 25DPO 4 (low-side aux)
34pin 26+13.8V ECU / injector power feed
34pin 29Air temperature (AVI, thermistor)
34pin 30Coolant temperature (AVI)
34pin 31Trigger (+) crank (VR or Hall)
34pin 32Home (+) cam (VR or Hall)
34pin 33Trigger (-) VR negative ref
34pin 34Home (-) VR negative ref

Other Haltech ECUs

The closest Haltech unit is the Haltech Nexus T1. Against it, this one has 0 knock inputs (the Nexus T1 has 1) and 29 pins (the Nexus T1 has 30).

Source: Haltech documentation for the Elite 550

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