MX-5 Miata NB2 2001-05 (BP-Z3, VVT; excludes Mazdaspeed) → Haltech Elite 2500 HT-151300 (auto)
MX-5 Miata NB2 2001-05 (BP-Z3, VVT; excludes Mazdaspeed) — Haltech — Elite 2500
Drawn by Michael Gnankou · Rev 0 · proposal · 2026-10-09
Before you start
Not confident with automotive wiring? Have a professional harness builder or tuner do it, or check your work before first power-up. A wiring mistake can damage the ECU, the engine or the car, or start a fire.
Install modifications
Steps on the car itself, outside the harness. Every harness for this car inherits them.
- Re-route the pressure-sensor vacuum hose to the intake manifoldrequired
Re-route the pressure sensor's (Mazda "EGR boost sensor", pin 4AE) vacuum hose directly to the intake manifold, bypassing the EGR boost solenoid. The stock ECU multiplexes baro + MAP through that solenoid: with it off the sensor reads atmosphere, with it energized it reads manifold. After re-routing the sensor reads MAP only, so the standalone needs its own barometric source — its onboard baro sensor if fitted, or a separate baro sensor on a spare analog input. (Alternative, not recommended: keep the hose stock and have the ECU energize the solenoid permanently via a low-side output switched with ignition; this costs an output.)
Why: With the solenoid off (its default) the sensor reads atmospheric pressure, not manifold pressure, so a standalone that uses this sensor as its MAP input would read the wrong value.
Where: EGR boost solenoid and the pressure sensor's vacuum hose (sensor signal 4AE).
Source: Justin Barrera — Miata NA/NB wiring corrections
| Status | proposal · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | none |
| Size of the job | 55 wires · 8 connectors · 0 part lines |
| Tools | Crimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink |
| Order of work | 1. Check every part against the parts list. 2. Cut and label every wire (labels: Export → Wire labels). 3. Crimp and pin connector by connector, ticking the build checklist. 4. Run the bench test with nothing plugged in and the battery disconnected. 5. Only then connect the ECU and power up. |
Build checklist
Tick each box as you go. Continuity: meter from end to end, expect under 1 Ω.
| Wire | From | To | Gauge | Colour | Cut | Label | Crimp A | Crimp B | Pin A | Pin B | Continuity |
|---|---|---|---|---|---|---|---|---|---|---|---|
| W1 | OEM-2-P | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | OEM-4-AF | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | SP-14V-1 | ELITE2500-A-26 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | SP-14V-1 | ELITE2500-B-11 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | OEM-3-A | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-3-B | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | OEM-4-A | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-GND-1 | ELITE2500-A-10 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | SP-GND-1 | ELITE2500-A-11 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-4-O | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | SP-0V-1 | ELITE2500-B-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | SP-0V-1 | ELITE2500-B-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | SP-0V-1 | ELITE2500-B-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-4-L | ELITE2500-A-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-3-Y | ELITE2500-B-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | SP-0V-1 | ELITE2500-B-5 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-3-V | ELITE2500-B-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | SP-0V-1 | ELITE2500-B-6 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-4-M | ELITE2500-B-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-3-F | ELITE2500-A-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-3-I | ELITE2500-A-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W22 | OEM-2-A | ELITE2500-A-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W23 | OEM-2-D | ELITE2500-A-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W24 | OEM-2-G | ELITE2500-A-21 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W25 | OEM-2-J | ELITE2500-A-22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W26 | OEM-2-B | ELITE2500-A-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W27 | OEM-2-C | ELITE2500-A-18 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W28 | OEM-2-K | ELITE2500-A-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W29 | OEM-2-M | ELITE2500-A-24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W30 | OEM-3-H | ELITE2500-A-23 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W31 | OEM-3-J | ELITE2500-B-19 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W32 | OEM-3-P | ELITE2500-A-31 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W33 | OEM-2-Q | ELITE2500-A-32 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W34 | OEM-2-E | ELITE2500-A-33 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W35 | OEM-2-F | ELITE2500-A-34 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W36 | OEM-2-H | ELITE2500-A-27 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W37 | OEM-2-I | ELITE2500-A-28 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W38 | OEM-2-N | ELITE2500-A-29 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W39 | OEM-2-R | ELITE2500-A-30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W40 | OEM-3-E | ELITE2500-B-25 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W41 | OEM-3-M | ELITE2500-B-26 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W42 | OEM-4-X | ELITE2500-B-13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W43 | OEM-4-AE | ELITE2500-A-16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W44 | OEM-4-V | ELITE2500-A-17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W45 | OEM-4-AA | ELITE2500-A-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W46 | OEM-4-W | ELITE2500-B-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W47 | OEM-4-P | ELITE2500-B-4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W48 | OEM-4-N | ELITE2500-B-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W49 | OEM-4-AD | ELITE2500-B-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W50 | OEM-3-T | ELITE2500-B-8 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W51 | OEM-3-S | ELITE2500-B-9 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W52 | OEM-4-B | ELITE2500-B-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W53 | OEM-4-C | ELITE2500-B-7 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W54 | OEM-4-F | ELITE2500-A-15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W55 | OEM-4-H | ELITE2500-A-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ |
Bench test (before first power-up)
Pre-power install steps (make these cuts/modifications on the car first, then verify the checks below): Re-route the pressure-sensor vacuum hose to the intake manifold.
Battery disconnected, ECU and every sensor unplugged. Meter on resistance. Each pair below must read open (OL): a reading means a pinched wire, a stray strand or a mis-pinned cavity. Then check continuity of every wire (last column of the build checklist).
| # | Probe A | Probe B | Expect | Why | Reading |
|---|---|---|---|---|---|
| 1 | ELITE2500-A-26 | ELITE2500-A-10 | open (OL) | +12 V supply must not touch power ground | |
| 2 | ELITE2500-A-26 | ELITE2500-B-14 | open (OL) | +12 V supply must not touch sensor ground | |
| 3 | ELITE2500-A-9 | ELITE2500-B-14 | open (OL) | 5 V sensor reference must not touch sensor ground | |
| 4 | ELITE2500-A-10 | ELITE2500-A-9 | open (OL) | power ground must not touch 5 V sensor reference | |
| 5 | ELITE2500-A-26 | ELITE2500-A-9 | open (OL) | +12 V supply must not touch 5 V sensor reference |
If any reading doesn't match, stop and get help before powering up.
Revisions
| Rev | Label | By | Date |
|---|---|---|---|
| No revisions yet. | |||
Schematic
Connectors
ELITE2500-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | DPO 2 | — | W28 | — | 0.5 | OEM-2-K | — | — | — |
| 10 | Battery ground | — | W8 | — | 0.85 | SP-GND-1 | — | — | — |
| 11 | Battery ground | — | W9 | — | 0.85 | SP-GND-1 | — | — | — |
| 12 | +8V DC | — | — | — | — | — | — | — | — |
| 13 | 12V ignition input | — | — | — | — | — | — | — | — |
| 14 | AVI 10 (TPS) | — | W55 | — | 0.5 | OEM-4-H | — | — | — |
| 15 | AVI 9 (MAP) | — | W54 | — | 0.5 | OEM-4-F | — | — | — |
| 16 | AVI 2 | — | W43 | — | 0.5 | OEM-4-AE | — | — | — |
| 17 | AVI 3 | — | W44 | — | 0.5 | OEM-4-V | — | — | — |
| 18 | DPO 1 | — | W27 | — | 0.5 | OEM-2-C | — | — | — |
| 19 | INJ 1 | — | W22 | — | 0.5 | OEM-2-A | — | — | — |
| 2 | AVI 4 | — | W45 | — | 0.5 | OEM-4-AA | — | — | — |
| 20 | INJ 2 | — | W23 | — | 0.5 | OEM-2-D | — | — | — |
| 21 | INJ 3 | — | W24 | — | 0.5 | OEM-2-G | — | — | — |
| 22 | INJ 4 | — | W25 | — | 0.5 | OEM-2-J | — | — | — |
| 23 | DPO 3 | — | W30 | — | 0.5 | OEM-3-H | — | — | — |
| 24 | DPO 5 (fuel pump trigger) | — | W29 | — | 0.5 | OEM-2-M | — | — | — |
| 25 | DPO 6 (ECR OUT) | — | W26 | — | 0.5 | OEM-2-B | — | — | — |
| 26 | ECU injector power input | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
| 27 | INJ 5 | — | W36 | — | 0.5 | OEM-2-H | — | — | — |
| 28 | INJ 6 | — | W37 | — | 0.5 | OEM-2-I | — | — | — |
| 29 | INJ 7 | — | W38 | — | 0.5 | OEM-2-N | — | — | — |
| 3 | IGN 1 | — | W20 | — | 0.5 | OEM-3-F | — | — | — |
| 30 | INJ 8 | — | W39 | — | 0.5 | OEM-2-R | — | — | — |
| 31 | Stepper 1 P1 / DPO | — | W32 | — | 0.5 | OEM-3-P | — | — | — |
| 32 | Stepper 1 P2 / DPO | — | W33 | — | 0.5 | OEM-2-Q | — | — | — |
| 33 | Stepper 1 P3 / DPO | — | W34 | — | 0.5 | OEM-2-E | — | — | — |
| 34 | Stepper 1 P4 / DPO | — | W35 | — | 0.5 | OEM-2-F | — | — | — |
| 4 | IGN 2 | — | W21 | — | 0.5 | OEM-3-I | — | — | — |
| 5 | IGN 3 | — | — | — | — | — | — | — | — |
| 6 | IGN 4 | — | — | — | — | — | — | — | — |
| 7 | IGN 5 | — | — | — | — | — | — | — | — |
| 8 | IGN 6 | — | — | — | — | — | — | — | — |
| 9 | +5V DC | — | W14 | — | 0.5 | OEM-4-L | — | — | — |
ELITE2500-B
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Crank (Trigger) (+) | — | W15 | — | 0.5 | OEM-3-Y | — | — | — |
| 10 | SPI 3 | — | W52 | — | 0.5 | OEM-4-B | — | — | — |
| 11 | +13.8V ECU supply | — | W4 | — | 0.85 | SP-14V-1 | — | — | — |
| 12 | AVI 6 (O2 Input 1) | — | W48 | — | 0.5 | OEM-4-N | — | — | — |
| 13 | AVI 1 (O2 Input 2) | — | W42 | — | 0.5 | OEM-4-X | — | — | — |
| 14 | Signal ground | — | W11 | — | 0.5 | SP-0V-1 | — | — | — |
| 15 | Signal ground | — | W12 | — | 0.5 | SP-0V-1 | — | — | — |
| 16 | Signal ground | — | W13 | — | 0.5 | SP-0V-1 | — | — | — |
| 17 | IGN 7 | — | — | — | — | — | — | — | — |
| 18 | IGN 8 | — | — | — | — | — | — | — | — |
| 19 | DPO 4 | — | W31 | — | 0.5 | OEM-3-J | — | — | — |
| 2 | Cam (Home) (+) | — | W17 | — | 0.5 | OEM-3-V | — | — | — |
| 20 | AVI 5 | — | W46 | — | 0.5 | OEM-4-W | — | — | — |
| 21 | KNOCK 1 | — | W19 | — | 0.5 | OEM-4-M | — | — | — |
| 22 | KNOCK 2 | — | — | — | — | — | — | — | — |
| 23 | CAN H | — | — | — | — | — | — | — | — |
| 24 | CAN L | — | — | — | — | — | — | — | — |
| 25 | DBW 1 / DPO | — | W40 | — | 0.5 | OEM-3-E | — | — | — |
| 26 | DBW 2 / DPO | — | W41 | — | 0.5 | OEM-3-M | — | — | — |
| 3 | AVI 7 (Air Temp) | — | W49 | — | 0.5 | OEM-4-AD | — | — | — |
| 4 | AVI 8 (Coolant Temp) | — | W47 | — | 0.5 | OEM-4-P | — | — | — |
| 5 | Crank (Trigger) (−) | — | W16 | — | 0.5 | SP-0V-1 | — | — | — |
| 6 | Cam (Home) (−) | — | W18 | — | 0.5 | SP-0V-1 | — | — | — |
| 7 | SPI 4 | — | W53 | — | 0.5 | OEM-4-C | — | — | — |
| 8 | SPI 1 | — | W50 | — | 0.5 | OEM-3-T | — | — | — |
| 9 | SPI 2 | — | W51 | — | 0.5 | OEM-3-S | — | — | — |
OEM-2
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Injector 1 | — | W22 | — | 0.5 | ELITE2500-A-19 | — | — | — |
| B | Cooling fan relay | — | W26 | — | 0.5 | ELITE2500-A-25 | — | — | — |
| C | Condenser fan relay | — | W27 | — | 0.5 | ELITE2500-A-18 | — | — | — |
| D | Injector 2 | — | W23 | — | 0.5 | ELITE2500-A-20 | — | — | — |
| E | EGR valve | — | W34 | — | 0.5 | ELITE2500-A-33 | — | — | — |
| F | EGR valve | — | W35 | — | 0.5 | ELITE2500-A-34 | — | — | — |
| G | Injector 3 | — | W24 | — | 0.5 | ELITE2500-A-21 | — | — | — |
| H | EGR valve | — | W36 | — | 0.5 | ELITE2500-A-27 | — | — | — |
| I | EGR valve | — | W37 | — | 0.5 | ELITE2500-A-28 | — | — | — |
| J | Injector 4 | — | W25 | — | 0.5 | ELITE2500-A-22 | — | — | — |
| K | A/C clutch relay | — | W28 | — | 0.5 | ELITE2500-A-1 | — | — | — |
| M | Fuel pump relay | — | W29 | — | 0.5 | ELITE2500-A-24 | — | — | — |
| N | VTCS solenoid (intake butterflies) | — | W38 | — | 0.5 | ELITE2500-A-29 | — | — | — |
| P | ISC valve +14V feed | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| Q | ISC valve low side | — | W33 | — | 0.5 | ELITE2500-A-32 | — | — | — |
| R | Malfunction indicator lamp (MIL) | — | W39 | — | 0.5 | ELITE2500-A-30 | — | — | — |
OEM-3
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Power ground | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| B | Power ground | — | W6 | — | 0.85 | SP-GND-1 | — | — | — |
| D | EGR boost solenoid | — | — | — | — | — | — | — | — |
| E | Charcoal canister purge | — | W40 | — | 0.5 | ELITE2500-B-25 | — | — | — |
| F | Ignition 1 (coils 1+4, wasted spark) | — | W20 | — | 0.5 | ELITE2500-A-3 | — | — | — |
| H | Main relay | — | W30 | — | 0.5 | ELITE2500-A-23 | — | — | — |
| I | Ignition 2 (coils 2+3, wasted spark) | — | W21 | — | 0.5 | ELITE2500-A-4 | — | — | — |
| J | Front O2 heater | — | W31 | — | 0.5 | ELITE2500-B-19 | — | — | — |
| M | Alternator control | — | W41 | — | 0.5 | ELITE2500-B-26 | — | — | — |
| O | Tachometer output | — | — | — | — | — | — | — | — |
| P | Rear O2 heater | — | W32 | — | 0.5 | ELITE2500-A-31 | — | — | — |
| S | Immobiliser | — | W51 | — | 0.5 | ELITE2500-B-9 | — | — | — |
| T | Vehicle speed | — | W50 | — | 0.5 | ELITE2500-B-8 | — | — | — |
| U | Charge lamp | — | — | — | — | — | — | — | — |
| V | Cam position (CMP) | — | W17 | — | 0.5 | ELITE2500-B-2 | — | — | — |
| Y | Crank position (CKP) | — | W15 | — | 0.5 | ELITE2500-B-1 | — | — | — |
OEM-4
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A | Power ground | — | W7 | — | 0.85 | SP-GND-1 | — | — | — |
| AA | Rear O2 signal | — | W45 | — | 0.5 | ELITE2500-A-2 | — | — | — |
| AD | Fuel level | — | W49 | — | 0.5 | ELITE2500-B-3 | — | — | — |
| AE | Pressure sensor (Mazda: EGR boost sensor) | — | W43 | — | 0.5 | ELITE2500-A-16 | — | — | — |
| AF | ECU power +14V (main relay) | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| AG | Constant +12V | — | — | — | — | — | — | — | — |
| B | Brake switch | — | W52 | — | 0.5 | ELITE2500-B-10 | — | — | — |
| C | Power steering pressure switch | — | W53 | — | 0.5 | ELITE2500-B-7 | — | — | — |
| D | VVT oil-control solenoid | — | — | — | — | — | — | — | — |
| F | A/C request | — | W54 | — | 0.5 | ELITE2500-A-15 | — | — | — |
| H | Neutral switch | — | W55 | — | 0.5 | ELITE2500-A-14 | — | — | — |
| I | Clutch switch | — | — | — | — | — | — | — | — |
| J | VTCS vacuum switch | — | — | — | — | — | — | — | — |
| L | +5V sensor supply | — | W14 | — | 0.5 | ELITE2500-A-9 | — | — | — |
| M | Knock sensor | — | W19 | — | 0.5 | ELITE2500-B-21 | — | — | — |
| N | Intake air temperature (IAT) | — | W48 | — | 0.5 | ELITE2500-B-12 | — | — | — |
| O | Signal ground | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| P | Coolant temperature (ECT) | — | W47 | — | 0.5 | ELITE2500-B-4 | — | — | — |
| V | Throttle position (TPS) | — | W44 | — | 0.5 | ELITE2500-A-17 | — | — | — |
| W | Front O2 signal | — | W46 | — | 0.5 | ELITE2500-B-20 | — | — | — |
| X | Mass air flow (MAF) | — | W42 | — | 0.5 | ELITE2500-B-13 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W10 | — | 0.5 | OEM-4-O | — | — | — |
| 1 | — | — | W11 | — | 0.5 | ELITE2500-B-14 | — | — | — |
| 1 | — | — | W12 | — | 0.5 | ELITE2500-B-15 | — | — | — |
| 1 | — | — | W13 | — | 0.5 | ELITE2500-B-16 | — | — | — |
| 1 | — | — | W16 | — | 0.5 | ELITE2500-B-5 | — | — | — |
| 1 | — | — | W18 | — | 0.5 | ELITE2500-B-6 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-2-P | — | — | — |
| 1 | — | — | W2 | — | 0.85 | OEM-4-AF | — | — | — |
| 1 | — | — | W3 | — | 0.85 | ELITE2500-A-26 | — | — | — |
| 1 | — | — | W4 | — | 0.85 | ELITE2500-B-11 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W5 | — | 0.85 | OEM-3-A | — | — | — |
| 1 | — | — | W6 | — | 0.85 | OEM-3-B | — | — | — |
| 1 | — | — | W7 | — | 0.85 | OEM-4-A | — | — | — |
| 1 | — | — | W8 | — | 0.85 | ELITE2500-A-10 | — | — | — |
| 1 | — | — | W9 | — | 0.85 | ELITE2500-A-11 | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-2-A | Injector 1 | injector_out | ELITE2500-A-19 | INJ 1 | injector_out | single_source | |
| OEM-2-B | Cooling fan relay | low_side_out | ELITE2500-A-25 | DPO 6 (ECR OUT) | low_side_out | single_source | |
| OEM-2-C | Condenser fan relay | low_side_out | ELITE2500-A-18 | DPO 1 | low_side_out | single_source | |
| OEM-2-D | Injector 2 | injector_out | ELITE2500-A-20 | INJ 2 | injector_out | single_source | |
| OEM-2-E | EGR valve | low_side_out | ELITE2500-A-33 | Stepper 1 P3 / DPO | switch_out | single_source | |
| OEM-2-F | EGR valve | low_side_out | ELITE2500-A-34 | Stepper 1 P4 / DPO | switch_out | single_source | |
| OEM-2-G | Injector 3 | injector_out | ELITE2500-A-21 | INJ 3 | injector_out | single_source | |
| OEM-2-H | EGR valve | low_side_out | ELITE2500-A-27 | INJ 5 | injector_out | single_source | |
| OEM-2-I | EGR valve | low_side_out | ELITE2500-A-28 | INJ 6 | injector_out | single_source | |
| OEM-2-J | Injector 4 | injector_out | ELITE2500-A-22 | INJ 4 | injector_out | single_source | |
| OEM-2-K | A/C clutch relay | low_side_out | ELITE2500-A-1 | DPO 2 | low_side_out | single_source | |
| OEM-2-M | Fuel pump relay | low_side_out | ELITE2500-A-24 | DPO 5 (fuel pump trigger) | low_side_out | single_source | |
| OEM-2-N | VTCS solenoid (intake butterflies) | low_side_out | ELITE2500-A-29 | INJ 7 | injector_out | single_source | |
| OEM-2-P | ISC valve +14V feed | power_in | ELITE2500-A-26 + ELITE2500-B-11 | ECU injector power input + +13.8V ECU supply | power_in | single_source | |
| OEM-2-Q | ISC valve low side | low_side_out | ELITE2500-A-32 | Stepper 1 P2 / DPO | switch_out | single_source | |
| OEM-2-R | Malfunction indicator lamp (MIL) | low_side_out | ELITE2500-A-30 | INJ 8 | injector_out | single_source | |
| OEM-3-A | Power ground | ground | ELITE2500-A-10 + ELITE2500-A-11 | Battery ground + Battery ground | ground | single_source | |
| OEM-3-B | Power ground | ground | ELITE2500-A-10 + ELITE2500-A-11 | Battery ground + Battery ground | ground | single_source | |
| OEM-3-D | EGR boost solenoid | — | — | — | — | single_source | |
| OEM-3-E | Charcoal canister purge | low_side_out | ELITE2500-B-25 | DBW 1 / DPO | hbridge_out | single_source | |
| OEM-3-F | Ignition 1 (coils 1+4, wasted spark) | ignition_out | ELITE2500-A-3 | IGN 1 | ignition_out | single_source | |
| OEM-3-H | Main relay | low_side_out | ELITE2500-A-23 | DPO 3 | low_side_out | single_source | |
| OEM-3-I | Ignition 2 (coils 2+3, wasted spark) | ignition_out | ELITE2500-A-4 | IGN 2 | ignition_out | single_source | |
| OEM-3-J | Front O2 heater | low_side_out | ELITE2500-B-19 | DPO 4 | low_side_out | single_source | |
| OEM-3-M | Alternator control | low_side_out | ELITE2500-B-26 | DBW 2 / DPO | hbridge_out | single_source | |
| OEM-3-O | Tachometer output | tacho_out | — | — | — | single_source | |
| OEM-3-P | Rear O2 heater | low_side_out | ELITE2500-A-31 | Stepper 1 P1 / DPO | switch_out | single_source | |
| OEM-3-S | Immobiliser | digital_in | ELITE2500-B-9 | SPI 2 | digital_in | single_source | |
| OEM-3-T | Vehicle speed | digital_in | ELITE2500-B-8 | SPI 1 | digital_in | single_source | |
| OEM-3-U | Charge lamp | low_side_out | — | — | — | single_source | |
| OEM-3-V | Cam position (CMP) | trigger_in | ELITE2500-B-2 | Cam (Home) (+) | trigger_in | single_source | |
| OEM-3-Y | Crank position (CKP) | trigger_in | ELITE2500-B-1 | Crank (Trigger) (+) | trigger_in | single_source | |
| OEM-4-A | Power ground | ground | ELITE2500-A-10 + ELITE2500-A-11 | Battery ground + Battery ground | ground | single_source | |
| OEM-4-AA | Rear O2 signal | lambda_nb_in | ELITE2500-A-2 | AVI 4 | analog_in | single_source | |
| OEM-4-AD | Fuel level | analog_in | ELITE2500-B-3 | AVI 7 (Air Temp) | analog_in | single_source | |
| OEM-4-AE | Pressure sensor (Mazda: EGR boost sensor) | analog_in | ELITE2500-A-16 | AVI 2 | analog_in | corroborated | |
| OEM-4-AF | ECU power +14V (main relay) | power_in | ELITE2500-A-26 + ELITE2500-B-11 | ECU injector power input + +13.8V ECU supply | power_in | single_source | |
| OEM-4-AG | Constant +12V | power_in | — | — | — | single_source | |
| OEM-4-B | Brake switch | digital_in | ELITE2500-B-10 | SPI 3 | digital_in | single_source | |
| OEM-4-C | Power steering pressure switch | digital_in | ELITE2500-B-7 | SPI 4 | digital_in | single_source | |
| OEM-4-D | VVT oil-control solenoid | low_side_out | — | — | — | single_source | |
| OEM-4-F | A/C request | digital_in | ELITE2500-A-15 | AVI 9 (MAP) | analog_in | single_source | |
| OEM-4-H | Neutral switch | digital_in | ELITE2500-A-14 | AVI 10 (TPS) | analog_in | single_source | |
| OEM-4-I | Clutch switch | digital_in | — | — | — | single_source | |
| OEM-4-J | VTCS vacuum switch | digital_in | — | — | — | single_source | |
| OEM-4-L | +5V sensor supply | vref | ELITE2500-A-9 | +5V DC | vref | single_source | |
| OEM-4-M | Knock sensor | knock_in | ELITE2500-B-21 | KNOCK 1 | knock_in | single_source | |
| OEM-4-N | Intake air temperature (IAT) | temp_in | ELITE2500-B-12 | AVI 6 (O2 Input 1) | analog_in | single_source | |
| OEM-4-O | Signal ground | sensor_ground | ELITE2500-B-14 + ELITE2500-B-15 + ELITE2500-B-16 + ELITE2500-B-5 + ELITE2500-B-6 | Signal ground + Signal ground + Signal ground + Crank (Trigger) (−) + Cam (Home) (−) | sensor_ground + trigger_in | single_source | |
| OEM-4-P | Coolant temperature (ECT) | temp_in | ELITE2500-B-4 | AVI 8 (Coolant Temp) | analog_in | single_source | |
| OEM-4-V | Throttle position (TPS) | analog_in | ELITE2500-A-17 | AVI 3 | analog_in | single_source | |
| OEM-4-W | Front O2 signal | lambda_nb_in | ELITE2500-B-20 | AVI 5 | analog_in | single_source | |
| OEM-4-X | Mass air flow (MAF) | analog_in | ELITE2500-B-13 | AVI 1 (O2 Input 2) | analog_in | single_source |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-2-P | SP-14V-1 | 0.85 | no route | ISC valve +14V feed | — | |
| W2 | OEM-4-AF | SP-14V-1 | 0.85 | no route | ECU power +14V (main relay) | — | |
| W3 | SP-14V-1 | ELITE2500-A-26 | 0.85 | no route | ECU injector power input | — | |
| W4 | SP-14V-1 | ELITE2500-B-11 | 0.85 | no route | +13.8V ECU supply | — | |
| W5 | OEM-3-A | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W6 | OEM-3-B | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W7 | OEM-4-A | SP-GND-1 | 0.85 | no route | Power ground | — | |
| W8 | SP-GND-1 | ELITE2500-A-10 | 0.85 | no route | Battery ground | — | |
| W9 | SP-GND-1 | ELITE2500-A-11 | 0.85 | no route | Battery ground | — | |
| W10 | OEM-4-O | SP-0V-1 | 0.5 | no route | Signal ground | — | |
| W11 | SP-0V-1 | ELITE2500-B-14 | 0.5 | no route | Signal ground | — | |
| W12 | SP-0V-1 | ELITE2500-B-15 | 0.5 | no route | Signal ground | — | |
| W13 | SP-0V-1 | ELITE2500-B-16 | 0.5 | no route | Signal ground | — | |
| W14 | OEM-4-L | ELITE2500-A-9 | 0.5 | no route | +5V sensor supply | — | |
| W15 | OEM-3-Y | ELITE2500-B-1 | 0.5 | no route | Crank position (CKP) | — | |
| W16 | SP-0V-1 | ELITE2500-B-5 | 0.5 | no route | Crank (Trigger) (−) | — | |
| W17 | OEM-3-V | ELITE2500-B-2 | 0.5 | no route | Cam position (CMP) | — | |
| W18 | SP-0V-1 | ELITE2500-B-6 | 0.5 | no route | Cam (Home) (−) | — | |
| W19 | OEM-4-M | ELITE2500-B-21 | 0.5 | no route | Knock sensor | — | |
| W20 | OEM-3-F | ELITE2500-A-3 | 0.5 | no route | Ignition 1 (coils 1+4, wasted spark) | — | |
| W21 | OEM-3-I | ELITE2500-A-4 | 0.5 | no route | Ignition 2 (coils 2+3, wasted spark) | — | |
| W22 | OEM-2-A | ELITE2500-A-19 | 0.5 | no route | Injector 1 | — | |
| W23 | OEM-2-D | ELITE2500-A-20 | 0.5 | no route | Injector 2 | — | |
| W24 | OEM-2-G | ELITE2500-A-21 | 0.5 | no route | Injector 3 | — | |
| W25 | OEM-2-J | ELITE2500-A-22 | 0.5 | no route | Injector 4 | — | |
| W26 | OEM-2-B | ELITE2500-A-25 | 0.5 | no route | Cooling fan relay | — | |
| W27 | OEM-2-C | ELITE2500-A-18 | 0.5 | no route | Condenser fan relay | — | |
| W28 | OEM-2-K | ELITE2500-A-1 | 0.5 | no route | A/C clutch relay | — | |
| W29 | OEM-2-M | ELITE2500-A-24 | 0.5 | no route | Fuel pump relay | — | |
| W30 | OEM-3-H | ELITE2500-A-23 | 0.5 | no route | Main relay | — | |
| W31 | OEM-3-J | ELITE2500-B-19 | 0.5 | no route | Front O2 heater | — | |
| W32 | OEM-3-P | ELITE2500-A-31 | 0.5 | no route | Rear O2 heater | — | |
| W33 | OEM-2-Q | ELITE2500-A-32 | 0.5 | no route | ISC valve low side | — | |
| W34 | OEM-2-E | ELITE2500-A-33 | 0.5 | no route | EGR valve | — | |
| W35 | OEM-2-F | ELITE2500-A-34 | 0.5 | no route | EGR valve | — | |
| W36 | OEM-2-H | ELITE2500-A-27 | 0.5 | no route | EGR valve | — | |
| W37 | OEM-2-I | ELITE2500-A-28 | 0.5 | no route | EGR valve | — | |
| W38 | OEM-2-N | ELITE2500-A-29 | 0.5 | no route | VTCS solenoid (intake butterflies) | — | |
| W39 | OEM-2-R | ELITE2500-A-30 | 0.5 | no route | Malfunction indicator lamp (MIL) | — | |
| W40 | OEM-3-E | ELITE2500-B-25 | 0.5 | no route | Charcoal canister purge | — | |
| W41 | OEM-3-M | ELITE2500-B-26 | 0.5 | no route | Alternator control | — | |
| W42 | OEM-4-X | ELITE2500-B-13 | 0.5 | no route | Mass air flow (MAF) | — | |
| W43 | OEM-4-AE | ELITE2500-A-16 | 0.5 | no route | Pressure sensor (Mazda: EGR boost sensor) | — | |
| W44 | OEM-4-V | ELITE2500-A-17 | 0.5 | no route | Throttle position (TPS) | — | |
| W45 | OEM-4-AA | ELITE2500-A-2 | 0.5 | no route | Rear O2 signal | — | |
| W46 | OEM-4-W | ELITE2500-B-20 | 0.5 | no route | Front O2 signal | — | |
| W47 | OEM-4-P | ELITE2500-B-4 | 0.5 | no route | Coolant temperature (ECT) | — | |
| W48 | OEM-4-N | ELITE2500-B-12 | 0.5 | no route | Intake air temperature (IAT) | — | |
| W49 | OEM-4-AD | ELITE2500-B-3 | 0.5 | no route | Fuel level | — | |
| W50 | OEM-3-T | ELITE2500-B-8 | 0.5 | no route | Vehicle speed | — | |
| W51 | OEM-3-S | ELITE2500-B-9 | 0.5 | no route | Immobiliser | — | |
| W52 | OEM-4-B | ELITE2500-B-10 | 0.5 | no route | Brake switch | — | |
| W53 | OEM-4-C | ELITE2500-B-7 | 0.5 | no route | Power steering pressure switch | — | |
| W54 | OEM-4-F | ELITE2500-A-15 | 0.5 | no route | A/C request | — | |
| W55 | OEM-4-H | ELITE2500-A-14 | 0.5 | no route | Neutral switch | — |
Bill of materials
| Category | Part number | Manufacturer | Description | Qty | Unit |
|---|
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (16)
| Severity | Code | Subject | Message |
|---|---|---|---|
| warn | NET_FAMILY | OEM-3-E ↔ ELITE2500-B-25 | OEM-3-E "Charcoal canister purge" [low_side_out] is wired to ELITE2500-B-25 "DBW 1 / DPO" [hbridge_out]. A half-bridge can act as a low-side switch only if configured that way. |
| warn | NET_FAMILY | OEM-3-M ↔ ELITE2500-B-26 | OEM-3-M "Alternator control" [low_side_out] is wired to ELITE2500-B-26 "DBW 2 / DPO" [hbridge_out]. A half-bridge can act as a low-side switch only if configured that way. |
| warn | NET_FAMILY | OEM-4-F ↔ ELITE2500-A-15 | OEM-4-F "A/C request" [digital_in] is wired to ELITE2500-A-15 "AVI 9 (MAP)" [analog_in]. Analog and digital on one net. A switch on an analog input works with a pull-up and a threshold; an analog sensor on a digital input loses its value. |
| warn | NET_FAMILY | OEM-4-H ↔ ELITE2500-A-14 | OEM-4-H "Neutral switch" [digital_in] is wired to ELITE2500-A-14 "AVI 10 (TPS)" [analog_in]. Analog and digital on one net. A switch on an analog input works with a pull-up and a threshold; an analog sensor on a digital input loses its value. |
| info | NET_FAMILY | ELITE2500-B-14 ↔ ELITE2500-B-6 | ELITE2500-B-14 "Signal ground" [sensor_ground] is wired to ELITE2500-B-6 "Cam (Home) (−)" [trigger_in]. Trigger return tied to sensor/trigger ground: correct for single-ended trigger inputs. |
| info | NET_FAMILY | OEM-2-E ↔ ELITE2500-A-33 | OEM-2-E "EGR valve" [low_side_out] is wired to ELITE2500-A-33 "Stepper 1 P3 / DPO" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-2-F ↔ ELITE2500-A-34 | OEM-2-F "EGR valve" [low_side_out] is wired to ELITE2500-A-34 "Stepper 1 P4 / DPO" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-2-H ↔ ELITE2500-A-27 | OEM-2-H "EGR valve" [low_side_out] is wired to ELITE2500-A-27 "INJ 5" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-2-I ↔ ELITE2500-A-28 | OEM-2-I "EGR valve" [low_side_out] is wired to ELITE2500-A-28 "INJ 6" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-2-N ↔ ELITE2500-A-29 | OEM-2-N "VTCS solenoid (intake butterflies)" [low_side_out] is wired to ELITE2500-A-29 "INJ 7" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-2-Q ↔ ELITE2500-A-32 | OEM-2-Q "ISC valve low side" [low_side_out] is wired to ELITE2500-A-32 "Stepper 1 P2 / DPO" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-2-R ↔ ELITE2500-A-30 | OEM-2-R "Malfunction indicator lamp (MIL)" [low_side_out] is wired to ELITE2500-A-30 "INJ 8" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency. |
| info | NET_FAMILY | OEM-3-P ↔ ELITE2500-A-31 | OEM-3-P "Rear O2 heater" [low_side_out] is wired to ELITE2500-A-31 "Stepper 1 P1 / DPO" [switch_out]. Configure this output as low side. |
| info | NET_FAMILY | OEM-4-N ↔ ELITE2500-B-12 | OEM-4-N "Intake air temperature (IAT)" [temp_in] is wired to ELITE2500-B-12 "AVI 6 (O2 Input 1)" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
| info | NET_FAMILY | OEM-4-P ↔ ELITE2500-B-4 | OEM-4-P "Coolant temperature (ECT)" [temp_in] is wired to ELITE2500-B-4 "AVI 8 (Coolant Temp)" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
| info | UNMAPPED | OEM | 6 optional OEM pins are not mapped: OEM-3-D EGR boost solenoid; OEM-3-O Tachometer output; OEM-3-U Charge lamp; OEM-4-D VVT oil-control solenoid; OEM-4-I Clutch switch; OEM-4-J VTCS vacuum switch |
Accepted (1)
| Code | Subject | Reason | By |
|---|---|---|---|
| REQUIRED_UNMAPPED | OEM-4-AG | Battery-constant (memory) feed of the stock ECU: the new ECU has no such input, so it is not needed. | mapping-proposal |
Notes
Auto-mapped by auto_map() from the library pin data on 2026-10-09. Review every wire against both manuals before building. Not wired: - OEM-4 AG: Constant +12V: Haltech Elite 2500 has no battery-constant input; not needed - OEM-3 U: Charge lamp: no free low_side/ls_hs/injector/hbridge on Haltech Elite 2500 - OEM-4 D: VVT oil-control solenoid: no free low_side/ls_hs/injector/hbridge on Haltech Elite 2500 - OEM-3 O: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on Haltech Elite 2500 - OEM-4 I: Clutch switch: no free switch_in/frequency_in/analog_0_5 on Haltech Elite 2500 - OEM-4 J: VTCS vacuum switch: no free switch_in/frequency_in/analog_0_5 on Haltech Elite 2500 - OEM-3 D: EGR boost solenoid: not classified in the library; wire by hand - ELITE2500-A 13: 12V ignition input: not fed (the stock ECU has no ignition-sense pin); feed it from a switched-ignition source
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | Haltech Elite 2500 (HT-151300) spec sheet | https://joeblospeedshop.com/wp-content/uploads/2023/11/HT-151300_SPEC-SHEET-2500-ELITE.pdf | archive | 2026-10-05 | c97da78cb851 |
| 4 | vendor_doc | Haltech Elite 2500 — 26-pin connector pinout | https://support.haltech.com/portal/en/kb/articles/main-connector-26-pin-elite2500 | archive | 2026-10-05 | ea6fd4d27ac7 |
| 4 | vendor_doc | Haltech Elite 2500 — 34-pin main connector pinout | https://support.haltech.com/portal/en/kb/articles/main-connector-34-pin-elite2500 | archive | 2026-10-05 | 4e633dff8340 |
| 4 | vendor_doc | Link G4X MX5NB2X install manual (NB2 2001-05) | https://linkecu.com/documentation/MX5XNB2.pdf | archive | 2026-10-05 | 741efdd9f2c8 |
| 4 | oem_manual | Mazda MX-5 NB2 (2003) wiring diagram — engine / starting / charging | https://web.archive.org/web/20191104195207/http://mellens.net/mazda/mazda_miata_extra_manual/2003_wiring.pdf | — | 2026-10-05 | 5ee0777f12c1 |
| 2 | expert_report | Justin Barrera — Miata NA/NB wiring corrections | — | — | — | — |