Toyota Supra A70 1986-92 (7M-GTE) → Link G4X AtomX 111-4000 (auto)
Toyota Supra A70 1986-92 (7M-GTE) — Link — G4X AtomX
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-12
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 | 2: read the Findings page before cutting any wire |
| Size of the job | 14 wires · 6 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-A-26 | SP-GND-1 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W2 | SP-GND-1 | G4XATOMX-A-A25 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | SP-GND-1 | G4XATOMX-A-A34 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-B-9 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | SP-0V-1 | G4XATOMX-A-A24 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-A-12 | G4XATOMX-A-A4 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | OEM-A-11 | G4XATOMX-A-A3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | OEM-A-25 | G4XATOMX-A-A2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-B-11 | G4XATOMX-A-A17 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-B-4 | G4XATOMX-A-A15 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-B-2 | G4XATOMX-A-A30 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-B-6 | G4XATOMX-A-A22 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-B-3 | G4XATOMX-A-A16 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-D-9 | G4XATOMX-A-A31 | 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 |
|---|---|---|---|---|---|
| No supply/ground nets found to cross-check. | |||||
If any reading doesn't match, stop and get help before powering up.
Revisions
| Rev | Label | By | Date |
|---|---|---|---|
| No revisions yet. | |||
Schematic
Connectors
G4XATOMX-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| A1 | Injector 4 | — | — | — | — | — | — | — | — |
| A10 | Ignition 4 | — | — | — | — | — | — | — | — |
| A11 | Ignition 3 | — | — | — | — | — | — | — | — |
| A12 | Ignition 2 | — | — | — | — | — | — | — | — |
| A13 | Ignition 1 | — | — | — | — | — | — | — | — |
| A15 | Analog Temp 1 | — | W10 | — | 0.5 | OEM-B-4 | — | — | — |
| A16 | Analog Temp 2 | — | W13 | — | 0.5 | OEM-B-3 | — | — | — |
| A17 | Analog Volt 1 | — | W9 | — | 0.5 | OEM-B-11 | — | — | — |
| A18 | Aux 4 | — | — | — | — | — | — | — | — |
| A19 | Aux 3 | — | — | — | — | — | — | — | — |
| A2 | Injector 3 | — | W8 | — | 0.5 | OEM-A-25 | — | — | — |
| A20 | Aux 2 | — | — | — | — | — | — | — | — |
| A21 | Aux 1 | — | — | — | — | — | — | — | — |
| A22 | Analog Volt 2 | — | W12 | — | 0.5 | OEM-B-6 | — | — | — |
| A24 | Sensor Ground | — | W5 | — | 0.5 | SP-0V-1 | — | — | — |
| A25 | System Ground | — | W2 | — | 0.85 | SP-GND-1 | — | — | — |
| A28 | CAN H | — | — | — | — | — | — | — | — |
| A29 | CAN L | — | — | — | — | — | — | — | — |
| A3 | Injector 2 | — | W7 | — | 0.5 | OEM-A-11 | — | — | — |
| A30 | Digital Input 1 | — | W11 | — | 0.5 | OEM-B-2 | — | — | — |
| A31 | Digital Input 2 | — | W14 | — | 0.5 | OEM-D-9 | — | — | — |
| A32 | +5V Out | — | — | — | — | — | — | — | — |
| A33 | Analog Volt 3 | — | — | — | — | — | — | — | — |
| A34 | System Ground | — | W3 | — | 0.85 | SP-GND-1 | — | — | — |
| A4 | Injector 1 | — | W6 | — | 0.5 | OEM-A-12 | — | — | — |
| A5 | +14V ECU Power | — | — | — | — | — | — | — | — |
| A6 | Knock 1 | — | — | — | — | — | — | — | — |
| A7 | Shield Ground | — | — | — | — | — | — | — | — |
| A8 | Trigger 1 | — | — | — | — | — | — | — | — |
| A9 | Trigger 2 | — | — | — | — | — | — | — | — |
OEM-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 11 | Injectors 2 & 6 (No.20) | — | W7 | — | 0.5 | G4XATOMX-A-A3 | — | — | — |
| 12 | Injectors 1 & 4 (No.10) | — | W6 | — | 0.5 | G4XATOMX-A-A4 | — | — | — |
| 25 | Injectors 3 & 5 (No.30) | — | W8 | — | 0.5 | G4XATOMX-A-A2 | — | — | — |
| 26 | Power ground (E01/E02) | — | W1 | — | 0.85 | SP-GND-1 | — | — | — |
OEM-B
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 11 | Throttle position sensor (VTA) | — | W9 | — | 0.5 | G4XATOMX-A-A17 | — | — | — |
| 2 | Karman-vortex AFM signal (KS) | — | W11 | — | 0.5 | G4XATOMX-A-A30 | — | — | — |
| 3 | Intake air temp (THA) | — | W13 | — | 0.5 | G4XATOMX-A-A16 | — | — | — |
| 4 | Coolant temp (THW) | — | W10 | — | 0.5 | G4XATOMX-A-A15 | — | — | — |
| 6 | Primary O2 sensor (OX1) | — | W12 | — | 0.5 | G4XATOMX-A-A22 | — | — | — |
| 9 | Sensor ground (E2) | — | W4 | — | 0.5 | SP-0V-1 | — | — | — |
OEM-D
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 9 | Vehicle speed sensor (SPD) | — | W14 | — | 0.5 | G4XATOMX-A-A31 | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W4 | — | 0.5 | OEM-B-9 | — | — | — |
| 1 | — | — | W5 | — | 0.5 | G4XATOMX-A-A24 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-A-26 | — | — | — |
| 1 | — | — | W2 | — | 0.85 | G4XATOMX-A-A25 | — | — | — |
| 1 | — | — | W3 | — | 0.85 | G4XATOMX-A-A34 | — | — | — |
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 | G4XATOMX-A-A3 | Injector 2 | injector_out | corroborated | |
| OEM-A-12 | Injectors 1 & 4 (No.10) | injector_out | G4XATOMX-A-A4 | Injector 1 | injector_out | corroborated | |
| OEM-A-25 | Injectors 3 & 5 (No.30) | injector_out | G4XATOMX-A-A2 | Injector 3 | injector_out | corroborated | |
| OEM-A-26 | Power ground (E01/E02) | ground | G4XATOMX-A-A25 + G4XATOMX-A-A34 | System Ground + System Ground | ground | corroborated | |
| OEM-B-11 | Throttle position sensor (VTA) | analog_in | G4XATOMX-A-A17 | Analog Volt 1 | analog_in | corroborated | |
| OEM-B-2 | Karman-vortex AFM signal (KS) | digital_in | G4XATOMX-A-A30 | Digital Input 1 | digital_in | corroborated | |
| OEM-B-3 | Intake air temp (THA) | temp_in | G4XATOMX-A-A16 | Analog Temp 2 | temp_in | corroborated | |
| OEM-B-4 | Coolant temp (THW) | temp_in | G4XATOMX-A-A15 | Analog Temp 1 | temp_in | corroborated | |
| OEM-B-6 | Primary O2 sensor (OX1) | lambda_nb_in | G4XATOMX-A-A22 | Analog Volt 2 | analog_in | corroborated | |
| OEM-B-9 | Sensor ground (E2) | sensor_ground | G4XATOMX-A-A24 | Sensor Ground | sensor_ground | corroborated | |
| OEM-D-9 | Vehicle speed sensor (SPD) | digital_in | G4XATOMX-A-A31 | Digital Input 2 | digital_in | corroborated |
Cut list
| Wire | From | To | Gauge (mm²) | Colour | Length | Signal | Ident |
|---|---|---|---|---|---|---|---|
| W1 | OEM-A-26 | SP-GND-1 | 0.85 | no route | Power ground (E01/E02) | — | |
| W2 | SP-GND-1 | G4XATOMX-A-A25 | 0.85 | no route | System Ground | — | |
| W3 | SP-GND-1 | G4XATOMX-A-A34 | 0.85 | no route | System Ground | — | |
| W4 | OEM-B-9 | SP-0V-1 | 0.5 | no route | Sensor ground (E2) | — | |
| W5 | SP-0V-1 | G4XATOMX-A-A24 | 0.5 | no route | Sensor Ground | — | |
| W6 | OEM-A-12 | G4XATOMX-A-A4 | 0.5 | no route | Injectors 1 & 4 (No.10) | — | |
| W7 | OEM-A-11 | G4XATOMX-A-A3 | 0.5 | no route | Injectors 2 & 6 (No.20) | — | |
| W8 | OEM-A-25 | G4XATOMX-A-A2 | 0.5 | no route | Injectors 3 & 5 (No.30) | — | |
| W9 | OEM-B-11 | G4XATOMX-A-A17 | 0.5 | no route | Throttle position sensor (VTA) | — | |
| W10 | OEM-B-4 | G4XATOMX-A-A15 | 0.5 | no route | Coolant temp (THW) | — | |
| W11 | OEM-B-2 | G4XATOMX-A-A30 | 0.5 | no route | Karman-vortex AFM signal (KS) | — | |
| W12 | OEM-B-6 | G4XATOMX-A-A22 | 0.5 | no route | Primary O2 sensor (OX1) | — | |
| W13 | OEM-B-3 | G4XATOMX-A-A16 | 0.5 | no route | Intake air temp (THA) | — | |
| W14 | OEM-D-9 | G4XATOMX-A-A31 | 0.5 | no route | Vehicle speed sensor (SPD) | — |
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 (3)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | INJECTOR_BALLAST | G4X AtomX | The 7M-GTE injectors (7M-GTE fuel injector) are low-impedance, but G4X AtomX 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. |
| error | PHYS_REQUIRED_OPEN | G4XATOMX-A-A5 | G4XATOMX-A-A5 "+14V ECU Power" is required but not wired. |
| 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. |
Accepted (0)
| Code | Subject | Reason | By |
|---|
Notes
Auto-mapped by auto_map() from the library pin data on 2026-10-11. Review every wire against both manuals before building. Open items: - Main-relay feed: no ecu_main_power pin on the stock or the new ECU - G4XATOMX-A A5: +14V ECU Power: required by Link G4X AtomX but no stock pin feeds it; wire by hand - Fuel-pump control: Link G4X AtomX 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). Add a fuel-pump relay on a spare low-side output — see the install notes for this car.
Sources
| Reliability | Kind | Title | URL | Archive | Captured | SHA-256 |
|---|---|---|---|---|---|---|
| 4 | vendor_doc | Link: G4X AtomX quickstart | https://linkecu.com/documentation/AtomXQuickstartGuide.pdf | archive | 2026-10-05 | 5fa903ea7bdf |
| 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 | — | — | — |
| 3 | community_copy | YourSpec: Link G4X AtomX ECU flying-lead harness wiring list | https://wpm.yourspec.com/projects/view/1462 | — | — | — |
| 2 | forum | AllPinouts: 1989–1992 Toyota Supra ECU | https://allpinouts.org/pinouts/connectors/car/1989-1992-toyota-supra-ecu/ | — | — | — |