Toyota Supra A70 1986-92 (7M-GTE) → Emtron SL4 (auto)
Toyota Supra A70 1986-92 (7M-GTE) — Emtron — SL4
⚠ 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 · 7 connectors · 3 part lines |
| Tools | Crimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink |
| Terminals | 3-1447221-4 |
| 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 | SL4-B-18 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W3 | SP-GND-1 | SL4-B-26 | 0.85 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W4 | OEM-B-9 | SP-0V-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W5 | SP-0V-1 | SL4-B-10 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W6 | OEM-A-12 | SL4-A-1 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W7 | OEM-A-11 | SL4-A-2 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W8 | OEM-A-25 | SL4-A-3 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W9 | OEM-B-11 | SL4-B-11 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W10 | OEM-B-4 | SL4-B-12 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W11 | OEM-B-2 | SL4-A-20 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W12 | OEM-B-6 | SL4-B-13 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W13 | OEM-B-3 | SL4-B-14 | 0.5 | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | ☐ | |
| W14 | OEM-D-9 | SL4-A-21 | 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
OEM-A
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 11 | Injectors 2 & 6 (No.20) | — | W7 | — | 0.5 | SL4-A-2 | — | — | — |
| 12 | Injectors 1 & 4 (No.10) | — | W6 | — | 0.5 | SL4-A-1 | — | — | — |
| 25 | Injectors 3 & 5 (No.30) | — | W8 | — | 0.5 | SL4-A-3 | — | — | — |
| 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 | SL4-B-11 | — | — | — |
| 2 | Karman-vortex AFM signal (KS) | — | W11 | — | 0.5 | SL4-A-20 | — | — | — |
| 3 | Intake air temp (THA) | — | W13 | — | 0.5 | SL4-B-14 | — | — | — |
| 4 | Coolant temp (THW) | — | W10 | — | 0.5 | SL4-B-12 | — | — | — |
| 6 | Primary O2 sensor (OX1) | — | W12 | — | 0.5 | SL4-B-13 | — | — | — |
| 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 | SL4-A-21 | — | — | — |
SL4-A
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Injection channel 1 | — | W6 | — | 0.5 | OEM-A-12 | — | — | — |
| 2 | Injection channel 2 | — | W7 | — | 0.5 | OEM-A-11 | — | — | — |
| 3 | Injection channel 3 | — | W8 | — | 0.5 | OEM-A-25 | — | — | — |
| 4 | Injection channel 4 | — | — | — | — | — | — | — | — |
| 5 | NC | — | — | — | — | — | — | — | — |
| 6 | NC | — | — | — | — | — | — | — | — |
| 7 | NC | — | — | — | — | — | — | — | — |
| 8 | NC | — | — | — | — | — | — | — | — |
| 9 | Sensor supply 8V | — | — | — | — | — | — | — | — |
| 10 | Auxiliary output 1 | — | — | — | — | — | — | — | — |
| 11 | Auxiliary output 2 | — | — | — | — | — | — | — | — |
| 12 | Auxiliary output 3 | — | — | — | — | — | — | — | — |
| 13 | Auxiliary output 4 | — | — | — | — | — | — | — | — |
| 14 | Auxiliary output 5 | — | — | — | — | — | — | — | — |
| 15 | Auxiliary output 6 | — | — | — | — | — | — | — | — |
| 16 | Auxiliary output 7 | — | — | — | — | — | — | — | — |
| 17 | Auxiliary output 8 | — | — | — | — | — | — | — | — |
| 18 | Auxiliary output 9 | — | — | — | — | — | — | — | — |
| 19 | Auxiliary output 10 | — | — | — | — | — | — | — | — |
| 20 | Digital input 1 | — | W11 | — | 0.5 | OEM-B-2 | — | — | — |
| 21 | Digital input 2 | — | W14 | — | 0.5 | OEM-D-9 | — | — | — |
| 22 | Digital input 3 | — | — | — | — | — | — | — | — |
| 23 | Digital input 4 | — | — | — | — | — | — | — | — |
| 24 | Digital input 5 | — | — | — | — | — | — | — | — |
| 25 | Digital input 6 | — | — | — | — | — | — | — | — |
| 26 | Ignition channel 1 | — | — | — | — | — | — | — | — |
| 27 | Ignition channel 2 | — | — | — | — | — | — | — | — |
| 28 | Ignition channel 3 | — | — | — | — | — | — | — | — |
| 29 | Ignition channel 4 | — | — | — | — | — | — | — | — |
| 30 | NC | — | — | — | — | — | — | — | — |
| 31 | NC | — | — | — | — | — | — | — | — |
| 32 | NC | — | — | — | — | — | — | — | — |
| 33 | NC | — | — | — | — | — | — | — | — |
| 34 | Aux 9–10 14V supply | — | — | — | — | — | — | — | — |
SL4-B
Mating face
Wire side
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | ECU 14V supply | — | — | — | — | — | — | — | — |
| 2 | Sensor supply Vref1 5.0V | — | — | — | — | — | — | — | — |
| 3 | EFI relay output (low side, 200 mA) | — | — | — | — | — | — | — | — |
| 4 | Ignition switch input | — | — | — | — | — | — | — | — |
| 5 | Crank index sensor + | — | — | — | — | — | — | — | — |
| 6 | Crank index sensor − | — | — | — | — | — | — | — | — |
| 7 | Sync sensor + | — | — | — | — | — | — | — | — |
| 8 | Sync sensor − | — | — | — | — | — | — | — | — |
| 9 | Shield (crank/sync/knock) | — | — | — | — | — | — | — | — |
| 10 | Analog sensor 0V reference | — | W5 | — | 0.5 | SP-0V-1 | — | — | — |
| 11 | Analog input 1 | — | W9 | — | 0.5 | OEM-B-11 | — | — | — |
| 12 | Analog input 2 | — | W10 | — | 0.5 | OEM-B-4 | — | — | — |
| 13 | Analog input 3 | — | W12 | — | 0.5 | OEM-B-6 | — | — | — |
| 14 | Analog input 4 | — | W13 | — | 0.5 | OEM-B-3 | — | — | — |
| 15 | Analog input 5 | — | — | — | — | — | — | — | — |
| 16 | Knock 1 + | — | — | — | — | — | — | — | — |
| 17 | Knock 1 − | — | — | — | — | — | — | — | — |
| 18 | ECU ground | — | W2 | — | 0.85 | SP-GND-1 | — | — | — |
| 19 | Analog input 6 | — | — | — | — | — | — | — | — |
| 20 | Analog input 7 (switchable 1k pull-up) | — | — | — | — | — | — | — | — |
| 21 | Analog input 8 (switchable 1k pull-up) | — | — | — | — | — | — | — | — |
| 22 | Analog input 9 (switchable 1k pull-up) | — | — | — | — | — | — | — | — |
| 23 | Analog input 10 (switchable 1k pull-up) | — | — | — | — | — | — | — | — |
| 24 | Knock 2 + | — | — | — | — | — | — | — | — |
| 25 | Knock 2 − | — | — | — | — | — | — | — | — |
| 26 | ECU ground | — | W3 | — | 0.85 | SP-GND-1 | — | — | — |
| 27 | CAN 1 H | — | — | — | — | — | — | — | — |
| 28 | CAN 1 L | — | — | — | — | — | — | — | — |
| 29 | NC | — | — | — | — | — | — | — | — |
| 30 | NC | — | — | — | — | — | — | — | — |
| 31 | Ethernet Tx + | — | — | — | — | — | — | — | — |
| 32 | Ethernet Tx − | — | — | — | — | — | — | — | — |
| 33 | Ethernet Rx + | — | — | — | — | — | — | — | — |
| 34 | Ethernet Rx − | — | — | — | — | — | — | — | — |
SP-0V
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W5 | — | 0.5 | SL4-B-10 | — | — | — |
| 1 | — | — | W4 | — | 0.5 | OEM-B-9 | — | — | — |
SP-GND
| Cavity | Function | Signal | Wire | Colour | Gauge (mm²) | Destination | Terminal | Seal | Plug |
|---|---|---|---|---|---|---|---|---|---|
| 1 | — | — | W1 | — | 0.85 | OEM-A-26 | — | — | — |
| 1 | — | — | W2 | — | 0.85 | SL4-B-18 | — | — | — |
| 1 | — | — | W3 | — | 0.85 | SL4-B-26 | — | — | — |
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 | SL4-A-2 | Injection channel 2 | injector_out | corroborated | |
| OEM-A-12 | Injectors 1 & 4 (No.10) | injector_out | SL4-A-1 | Injection channel 1 | injector_out | corroborated | |
| OEM-A-25 | Injectors 3 & 5 (No.30) | injector_out | SL4-A-3 | Injection channel 3 | injector_out | corroborated | |
| OEM-A-26 | Power ground (E01/E02) | ground | SL4-B-18 + SL4-B-26 | ECU ground + ECU ground | ground | corroborated | |
| OEM-B-11 | Throttle position sensor (VTA) | analog_in | SL4-B-11 | Analog input 1 | analog_in | corroborated | |
| OEM-B-2 | Karman-vortex AFM signal (KS) | digital_in | SL4-A-20 | Digital input 1 | digital_in | corroborated | |
| OEM-B-3 | Intake air temp (THA) | temp_in | SL4-B-14 | Analog input 4 | analog_in | corroborated | |
| OEM-B-4 | Coolant temp (THW) | temp_in | SL4-B-12 | Analog input 2 | analog_in | corroborated | |
| OEM-B-6 | Primary O2 sensor (OX1) | lambda_nb_in | SL4-B-13 | Analog input 3 | analog_in | corroborated | |
| OEM-B-9 | Sensor ground (E2) | sensor_ground | SL4-B-10 | Analog sensor 0V reference | sensor_ground | corroborated | |
| OEM-D-9 | Vehicle speed sensor (SPD) | digital_in | SL4-A-21 | 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 | SL4-B-18 | 0.85 | no route | ECU ground | — | |
| W3 | SP-GND-1 | SL4-B-26 | 0.85 | no route | ECU ground | — | |
| W4 | OEM-B-9 | SP-0V-1 | 0.5 | no route | Sensor ground (E2) | — | |
| W5 | SP-0V-1 | SL4-B-10 | 0.5 | no route | Analog sensor 0V reference | — | |
| W6 | OEM-A-12 | SL4-A-1 | 0.5 | no route | Injectors 1 & 4 (No.10) | — | |
| W7 | OEM-A-11 | SL4-A-2 | 0.5 | no route | Injectors 2 & 6 (No.20) | — | |
| W8 | OEM-A-25 | SL4-A-3 | 0.5 | no route | Injectors 3 & 5 (No.30) | — | |
| W9 | OEM-B-11 | SL4-B-11 | 0.5 | no route | Throttle position sensor (VTA) | — | |
| W10 | OEM-B-4 | SL4-B-12 | 0.5 | no route | Coolant temp (THW) | — | |
| W11 | OEM-B-2 | SL4-A-20 | 0.5 | no route | Karman-vortex AFM signal (KS) | — | |
| W12 | OEM-B-6 | SL4-B-13 | 0.5 | no route | Primary O2 sensor (OX1) | — | |
| W13 | OEM-B-3 | SL4-B-14 | 0.5 | no route | Intake air temp (THA) | — | |
| W14 | OEM-D-9 | SL4-A-21 | 0.5 | no route | Vehicle speed sensor (SPD) | — |
Bill of materials
| Category | Part number | Manufacturer | Description | Qty | Unit |
|---|---|---|---|---|---|
| connector | 4-1437290-0 | TE | Superseal 1.0 34-way plug, Key 1 | 1.000 | ea |
| connector | 4-1437290-1 | TE | Superseal 1.0 34-way plug, Key 2 | 1.000 | ea |
| terminal | 3-1447221-4 | TE | Superseal 1.0 socket terminal, 20 AWG (0.5 sq mm) | 12.000 | ea |
ECU setup sheet
| Role | Engine ref | Engine signal | Sensor | ECU point | ECU function | ECU class | Setup flag |
|---|---|---|---|---|---|---|---|
| No configured channels. | |||||||
Findings
Open (5)
| Severity | Code | Subject | Message |
|---|---|---|---|
| error | INJECTOR_BALLAST | SL4 | The 7M-GTE injectors (7M-GTE fuel injector) are low-impedance, but SL4 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 | SL4-B-1 | SL4-B-1 "ECU 14V supply" 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. |
| info | NET_FAMILY | OEM-B-3 ↔ SL4-B-14 | OEM-B-3 "Intake air temp (THA)" [temp_in] is wired to SL4-B-14 "Analog input 4" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
| info | NET_FAMILY | OEM-B-4 ↔ SL4-B-12 | OEM-B-4 "Coolant temp (THW)" [temp_in] is wired to SL4-B-12 "Analog input 2" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one. |
Accepted (0)
| Code | Subject | Reason | By |
|---|
Notes
Fit check: unconfirmed. Confirm these before building: - Trigger pattern for Toyota 7M-GTE not found in the ECU's docs (No 7M-GTE/7M-GE decoder.) - 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 2026-10-11. 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 - SL4-B 1: ECU 14V supply: required by Emtron SL4 but no stock pin feeds it; wire by hand - Fuel-pump control: Emtron SL4 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. Not wired: - SL4-B 4: Ignition switch 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 | Emtron SL4/SL6/SL8 ECU datasheets | https://docs.emtronaustralia.com.au/engine-management/datasheets/index.html | archive | 2026-10-05 | 1e22846cec94 |
| 4 | vendor_doc | Emtron SL4/SL6/SL8 pinout pages | https://docs.emtronaustralia.com.au/engine-management/wiring/index.html | archive | 2026-10-05 | e52b3da9996a |
| 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/ | — | — | — |