Toyota Supra A70 1986-92 (7M-GTE) → MaxxECU MaxxECU MINI REV10+ (auto)
Toyota Supra A70 1986-92 (7M-GTE) — MaxxECU — MaxxECU MINI
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-23
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.
| Status | draft · not yet verified: nobody has reported building and running this harness |
|---|---|
| Open errors | none |
| Size of the job | 21 wires · 7 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-D-12 | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | OEM-D-13 | SP-14V-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | SP-14V-1 | MAXXECUMINI-C1-H4 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-A-26 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | SP-GND-1 | MAXXECUMINI-C1-G4 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-B-9 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | SP-0V-1 | MAXXECUMINI-C1-A2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | SP-0V-1 | MAXXECUMINI-C1-B3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | SP-0V-1 | MAXXECUMINI-C1-B4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | SP-0V-1 | MAXXECUMINI-C1-D4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-A-12 | MAXXECUMINI-C1-G3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-A-11 | MAXXECUMINI-C1-H1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-A-25 | MAXXECUMINI-C1-H2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-D-4 | MAXXECUMINI-C1-G2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W15 | OEM-B-11 | MAXXECUMINI-C1-D2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W16 | OEM-B-4 | MAXXECUMINI-C1-C1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W17 | OEM-D-2 | MAXXECUMINI-C1-B1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W18 | OEM-B-6 | MAXXECUMINI-C1-C3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W19 | OEM-D-3 | MAXXECUMINI-C1-C2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W20 | OEM-D-9 | MAXXECUMINI-C1-B2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W21 | OEM-D-10 | MAXXECUMINI-C1-C4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ |
Bench test (before first power-up)
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 | MAXXECUMINI-C1-A2 | MAXXECUMINI-C1-H4 | open (OL) | sensor ground must not touch +12 V supply | |
| 2 | MAXXECUMINI-C1-G4 | MAXXECUMINI-C1-H4 | open (OL) | power ground must not touch +12 V supply |
If any reading doesn't match, stop and get help before powering up.
Revisions
| Rev | Label | By | Date |
|---|---|---|---|
| No revisions yet. | |||
Schematic
Connectors
MAXXECUMINI-C1
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A1 | TRIGGER | — | — | — | — | — | — | — | — |
| A2 | TRIGGER GND | — | W7 | — | 0.5 | SP-0V-1 | — | — | — |
| B1 | DIN 1 (Hall only) | — | W17 | — | 0.5 | OEM-D-2 | — | — | — |
| B2 | DIN 2 (Hall only) | — | W20 | — | 0.5 | OEM-D-9 | — | — | — |
| B3 | SENSOR GND | — | W8 | — | 0.5 | SP-0V-1 | — | — | — |
| B4 | SENSOR GND | — | W9 | — | 0.5 | SP-0V-1 | — | — | — |
| C1 | CLT | — | W16 | — | 0.5 | OEM-B-4 | — | — | — |
| C2 | IAT | — | W19 | — | 0.5 | OEM-D-3 | — | — | — |
| C3 | AIN 3 (0-5V) | — | W18 | — | 0.5 | OEM-B-6 | — | — | — |
| C4 | AIN 4 (0-5V) | — | W21 | — | 0.5 | OEM-D-10 | — | — | — |
| D1 | GPO 8/TACHO | — | — | — | — | — | — | — | — |
| D2 | TPS | — | W15 | — | 0.5 | OEM-B-11 | — | — | — |
| D3 | GND Shield | — | — | — | — | — | — | — | — |
| D4 | SENSOR GND | — | W10 | — | 0.5 | SP-0V-1 | — | — | — |
| E1 | GPO 3 | — | — | — | — | — | — | — | — |
| E2 | +5V sensor supply | — | — | — | — | — | — | — | — |
| E3 | CAN L | — | — | — | — | — | — | — | — |
| E4 | CAN H | — | — | — | — | — | — | — | — |
| F1 | IGN 1 | — | — | — | — | — | — | — | — |
| F2 | IGN 2 | — | — | — | — | — | — | — | — |
| F3 | IGN 3 | — | — | — | — | — | — | — | — |
| F4 | IGN 4 | — | — | — | — | — | — | — | — |
| G1 | GPO 2 | — | — | — | — | — | — | — | — |
| G2 | GPO 1 | — | W14 | — | 0.5 | OEM-D-4 | — | — | — |
| G3 | INJ 1 | — | W11 | — | 0.5 | OEM-A-12 | — | — | — |
| G4 | ENGINE GND | — | W5 | — | 0.85 | SP-GND-1 | — | — | — |
| H1 | INJ 2 | — | W12 | — | 0.5 | OEM-A-11 | — | — | — |
| H2 | INJ 3 | — | W13 | — | 0.5 | OEM-A-25 | — | — | — |
| H3 | INJ 4 | — | — | — | — | — | — | — | — |
| H4 | +12V (ECU power supply) | — | W3 | — | 0.85 | SP-14V-1 | — | — | — |
OEM-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 11 | Injectors 2 & 6 (No.20) | — | W12 | — | 0.5 | MAXXECUMINI-C1-H1 | — | — | — |
| 12 | Injectors 1 & 4 (No.10) | — | W11 | — | 0.5 | MAXXECUMINI-C1-G3 | — | — | — |
| 25 | Injectors 3 & 5 (No.30) | — | W13 | — | 0.5 | MAXXECUMINI-C1-H2 | — | — | — |
| 26 | Power ground (E01/E02) | — | W4 | — | 0.85 | SP-GND-1 | — | — | — |
OEM-B
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 11 | Throttle position sensor (VTA) | — | W15 | — | 0.5 | MAXXECUMINI-C1-D2 | — | — | — |
| 4 | Coolant temp (THW) | — | W16 | — | 0.5 | MAXXECUMINI-C1-C1 | — | — | — |
| 6 | Primary O2 sensor (OX1) | — | W18 | — | 0.5 | MAXXECUMINI-C1-C3 | — | — | — |
| 9 | Sensor ground (E1) | — | W6 | — | 0.5 | SP-0V-1 | — | — | — |
OEM-D
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 10 | A/C compressor request (A/C) | — | W21 | — | 0.5 | MAXXECUMINI-C1-C4 | — | — | — |
| 11 | Starter signal (STA) | — | — | — | — | — | — | — | — |
| 12 | EFI main relay power (+B) | — | W1 | — | 0.85 | SP-14V-1 | — | — | — |
| 13 | EFI main relay power (second feed) (+B1) | — | W2 | — | 0.85 | SP-14V-1 | — | — | — |
| 2 | Karman-vortex AFM signal (KS) | — | W17 | — | 0.5 | MAXXECUMINI-C1-B1 | — | — | — |
| 22 | Neutral start switch (NSW) | — | — | — | — | — | — | — | — |
| 3 | Intake air temp (THA) | — | W19 | — | 0.5 | MAXXECUMINI-C1-C2 | — | — | — |
| 4 | EFI main relay control (M-REL) | — | W14 | — | 0.5 | MAXXECUMINI-C1-G2 | — | — | — |
| 5 | Knock sensor 1 (KNK1) | — | — | — | — | — | — | — | — |
| 9 | Vehicle speed sensor (SPD) | — | W20 | — | 0.5 | MAXXECUMINI-C1-B2 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W6 | — | 0.5 | OEM-B-9 | — | — | — |
| 1 | — | — | W7 | — | 0.5 | MAXXECUMINI-C1-A2 | — | — | — |
| 1 | — | — | W8 | — | 0.5 | MAXXECUMINI-C1-B3 | — | — | — |
| 1 | — | — | W9 | — | 0.5 | MAXXECUMINI-C1-B4 | — | — | — |
| 1 | — | — | W10 | — | 0.5 | MAXXECUMINI-C1-D4 | — | — | — |
SP-14V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-D-12 | — | — | — |
| 1 | — | — | W2 | — | 0.85 | OEM-D-13 | — | — | — |
| 1 | — | — | W3 | — | 0.85 | MAXXECUMINI-C1-H4 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W4 | — | 0.85 | OEM-A-26 | — | — | — |
| 1 | — | — | W5 | — | 0.85 | MAXXECUMINI-C1-G4 | — | — | — |
Pin map
| OEM point | OEM function | OEM family | Target point | Target function | Target family | Wire colour | Evidence |
|---|---|---|---|---|---|---|---|
| OEM-A-11 | Injectors 2 & 6 (No.20) | injector_out | MAXXECUMINI-C1-H1 | INJ 2 | injector_out | corroborated | |
| OEM-A-12 | Injectors 1 & 4 (No.10) | injector_out | MAXXECUMINI-C1-G3 | INJ 1 | injector_out | corroborated | |
| OEM-A-25 | Injectors 3 & 5 (No.30) | injector_out | MAXXECUMINI-C1-H2 | INJ 3 | injector_out | corroborated | |
| OEM-A-26 | Power ground (E01/E02) | ground | MAXXECUMINI-C1-G4 | ENGINE GND | ground | corroborated | |
| OEM-B-11 | Throttle position sensor (VTA) | analog_in | MAXXECUMINI-C1-D2 | TPS | analog_in | corroborated | |
| OEM-B-4 | Coolant temp (THW) | temp_in | MAXXECUMINI-C1-C1 | CLT | temp_in | corroborated | |
| OEM-B-6 | Primary O2 sensor (OX1) | lambda_nb_in | MAXXECUMINI-C1-C3 | AIN 3 (0-5V) | analog_in | corroborated | |
| OEM-B-9 | Sensor ground (E1) | sensor_ground | MAXXECUMINI-C1-A2 + MAXXECUMINI-C1-B3 + MAXXECUMINI-C1-B4 + MAXXECUMINI-C1-D4 | TRIGGER GND + SENSOR GND + SENSOR GND + SENSOR GND | sensor_ground | corroborated | |
| OEM-D-10 | A/C compressor request (A/C) | digital_in | MAXXECUMINI-C1-C4 | AIN 4 (0-5V) | analog_in | single_source | |
| OEM-D-11 | Starter signal (STA) | digital_in | — | — | — | single_source | |
| OEM-D-12 | EFI main relay power (+B) | power_in | MAXXECUMINI-C1-H4 | +12V (ECU power supply) | power_in | single_source | |
| OEM-D-13 | EFI main relay power (second feed) (+B1) | power_in | MAXXECUMINI-C1-H4 | +12V (ECU power supply) | power_in | single_source | |
| OEM-D-2 | Karman-vortex AFM signal (KS) | digital_in | MAXXECUMINI-C1-B1 | DIN 1 (Hall only) | digital_in | single_source | |
| OEM-D-22 | Neutral start switch (NSW) | digital_in | — | — | — | single_source | |
| OEM-D-3 | Intake air temp (THA) | temp_in | MAXXECUMINI-C1-C2 | IAT | temp_in | single_source | |
| OEM-D-4 | EFI main relay control (M-REL) | low_side_out | MAXXECUMINI-C1-G2 | GPO 1 | low_side_out | single_source | |
| OEM-D-5 | Knock sensor 1 (KNK1) | knock_in | — | — | — | single_source | |
| OEM-D-9 | Vehicle speed sensor (SPD) | digital_in | MAXXECUMINI-C1-B2 | DIN 2 (Hall only) | digital_in | corroborated |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-D-12 | SP-14V-1 | 0.85 | no route | EFI main relay power (+B) | — | |
| W2 | OEM-D-13 | SP-14V-1 | 0.85 | no route | EFI main relay power (second feed) (+B1) | — | |
| W3 | SP-14V-1 | MAXXECUMINI-C1-H4 | 0.85 | no route | +12V (ECU power supply) | — | |
| W4 | OEM-A-26 | SP-GND-1 | 0.85 | no route | Power ground (E01/E02) | — | |
| W5 | SP-GND-1 | MAXXECUMINI-C1-G4 | 0.85 | no route | ENGINE GND | — | |
| W6 | OEM-B-9 | SP-0V-1 | 0.5 | no route | Sensor ground (E1) | — | |
| W7 | SP-0V-1 | MAXXECUMINI-C1-A2 | 0.5 | no route | TRIGGER GND | — | |
| W8 | SP-0V-1 | MAXXECUMINI-C1-B3 | 0.5 | no route | SENSOR GND | — | |
| W9 | SP-0V-1 | MAXXECUMINI-C1-B4 | 0.5 | no route | SENSOR GND | — | |
| W10 | SP-0V-1 | MAXXECUMINI-C1-D4 | 0.5 | no route | SENSOR GND | — | |
| W11 | OEM-A-12 | MAXXECUMINI-C1-G3 | 0.5 | no route | Injectors 1 & 4 (No.10) | — | |
| W12 | OEM-A-11 | MAXXECUMINI-C1-H1 | 0.5 | no route | Injectors 2 & 6 (No.20) | — | |
| W13 | OEM-A-25 | MAXXECUMINI-C1-H2 | 0.5 | no route | Injectors 3 & 5 (No.30) | — | |
| W14 | OEM-D-4 | MAXXECUMINI-C1-G2 | 0.5 | no route | EFI main relay control (M-REL) | — | |
| W15 | OEM-B-11 | MAXXECUMINI-C1-D2 | 0.5 | no route | Throttle position sensor (VTA) | — | |
| W16 | OEM-B-4 | MAXXECUMINI-C1-C1 | 0.5 | no route | Coolant temp (THW) | — | |
| W17 | OEM-D-2 | MAXXECUMINI-C1-B1 | 0.5 | no route | Karman-vortex AFM signal (KS) | — | |
| W18 | OEM-B-6 | MAXXECUMINI-C1-C3 | 0.5 | no route | Primary O2 sensor (OX1) | — | |
| W19 | OEM-D-3 | MAXXECUMINI-C1-C2 | 0.5 | no route | Intake air temp (THA) | — | |
| W20 | OEM-D-9 | MAXXECUMINI-C1-B2 | 0.5 | no route | Vehicle speed sensor (SPD) | — | |
| W21 | OEM-D-10 | MAXXECUMINI-C1-C4 | 0.5 | no route | A/C compressor request (A/C) | — |
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 (4)
| Severity | Code | Subject | Message |
|---|---|---|---|
| warn | INJECTOR_BALLAST | MaxxECU MINI | The 7M-GTE injectors (7M-GTE fuel injector) are low-impedance, but MaxxECU MINI drives saturated (high-Z) injectors only. Add a ballast resistor pack in series with each injector, or use an ECU with low-Z / peak-and-hold injector drivers. |
| warn | NET_FAMILY | OEM-D-10 ↔ MAXXECUMINI-C1-C4 | OEM-D-10 "A/C compressor request (A/C)" [digital_in] is wired to MAXXECUMINI-C1-C4 "AIN 4 (0-5V)" [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 | NO_FUEL_PUMP | fuel pump | This engine harness has no fuel-pump control path: no fuel-pump relay output is wired to the new ECU. If the stock car switches the pump outside the ECU (an airflow-meter contact or a separate module), the standalone must drive the pump relay itself — see the install notes for this car. |
| info | UNMAPPED | OEM | 2 optional OEM pins are not mapped: OEM-D-11 Starter signal (STA); OEM-D-22 Neutral start switch (NSW) |
Accepted (1)
| Code | Subject | Reason | By |
|---|---|---|---|
| REQUIRED_UNMAPPED | OEM-D-5 | Knock input is a documented capability limit: this ECU has no built-in knock sensor input, so the stock knock sensor cannot be wired to it (run without knock control, or add an external knock module). | mapping-proposal |
Notes
Fit check: needs add-on. Resolve these before building: - Low-impedance injectors need peak-hold drivers or ballast resistors - Trigger pattern for Toyota 7M-GTE not found in the ECU's docs (2026-10-23 re-check: no 7M-GE/7M-GTE mode in the MTune trigger list (no Nippondenso 24+2 CAS decoder; only generic multitooth modes).) - No knock input; the stock knock sensor would be unused - Only 4 ignition outputs for 6 cylinders: wasted spark (pair coils per firing order) - Only 4 injector outputs for 6 injectors: batch / semi-sequential injection Auto-mapped by auto_map() from the library pin data on 2026-10-23. Review every wire against both manuals before building. Open items: - OEM-D 5: Knock sensor 1 (KNK1): no free knock input on MaxxECU MaxxECU MINI - Fuel-pump control: MaxxECU MaxxECU MINI needs to drive the fuel pump, but the stock ECU has no fuel-pump output (an airflow-meter contact or a separate module runs it) and the ECU has no fuel-pump output pin to wire — add a fuel-pump relay on a spare low-side output, see the install notes for this car. Not wired: - OEM-D 11: Starter signal (STA): no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU MINI - OEM-D 22: Neutral start switch (NSW): no free switch_in/frequency_in/analog_0_5 on MaxxECU MaxxECU MINI
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 5 | oem_wiring_diagram | Toyota Supra A70 (MA70) 1990 EWD — TCCS (7M-GTE) System Circuit | — | — | — | — |
| 4 | vendor_doc | MaxxECU GEN1 pinout (MINI / STREET / SPORT / V1 / RACE / PRO) | http://www.maxxecu.com/webhelp/wirings-maxxecu_pinout.html | archive | 2026-10-05 | 2e37b6814690 |
| 4 | vendor_doc | Toyota 7M-GTE EFI manual — "Terminals of ECU" (complete terminal list, no pin numbers) | http://shoarmateam.nl/upload/Toyota-Other/Cressida/MX83/efi%20system%20+%20WIRING/toyota-7m-manual-efi-fi%5b1%5d.pdf | — | — | — |
| 2 | forum | AllPinouts: 1989–1992 Toyota Supra ECU | https://allpinouts.org/pinouts/connectors/car/1989-1992-toyota-supra-ecu/ | — | — | — |