The ECU - Electronic Control Unit fitted to the 1993–1998 Toyota Supra (JZA80 chassis) is the Engine Control Module (ECM) of Toyota’s TCCS (Toyota Computer Controlled System), which governs Sequential Fuel Injection (SFI), Electronic Spark Advance (ESA), and on-board self-diagnosis. Two engine variants were offered: the 2JZ-GTE (3.0 L DOHC 24-valve twin-turbocharged) and the 2JZ-GE (naturally aspirated). The ECM uses waterproof bolt-type multi-pin connectors; terminal measurement requires Toyota’s SST 09990-01000 check sub-harness — probing the sealed connector directly risks damaging the waterproof seals. Diagnostic fault codes are read by bridging terminals TE1 and E1 on the DLC1 check connector and counting pulses from the CHECK ENGINE warning lamp.
ECU - Electronic Control Unit Connector.
Connector A
| Pin | name | Signal |
|---|---|---|
| A2 | Vehicle Speed Sensor | Speed |
Connector B
| Pin | name | Signal |
|---|---|---|
| B43 | Throttle Position Sensor | Analog |
| B44 | Engine Coolant Temperature Sensor | Analog |
| B45 | Intake Air Temperature Sensor | Analog |
| B47 | Primary O2 Sensor | Analog |
| B48 | Secondary O2 Sensor | Analog |
| B57 | Ignition Control Module | RPM |
| B62 | MAP Sensor | Analog |
| B69 | Power Ground | Ground |
Notes
- The ECM connectors are waterproof bolt-type; always use SST 09990-01000 (Toyota Break-Out-Box check sub-harness) for live terminal measurement — never probe the sealed connector directly.
- The 2JZ-GTE variant adds turbo-specific terminals absent on the 2JZ-GE (e.g. FC fuel cut, twin CT12B turbocharger-related signals).
- The 2JZ-GTE ECM uses dual-track throttle position signals (VTA1 and VTA2); the 2JZ-GE layout is similar but omits turbo-specific assignments.
- Key reference voltages: BATT terminal 9–14 V (direct battery feed); VC reference output 4.5–5.5 V (5 V supply to sensors).
- IC (integrated circuit) components inside the ECM are sensitive to electrostatic discharge; do not open the ECM cover.
- To read OBD-1 diagnostic codes, bridge TE1 and E1 on the DLC1 connector; the CHECK ENGINE lamp blinks codes using 0.25-second pulses, with a 1.5-second pause between digits and a 2.5-second pause between codes.
Signals
- A2 (Vehicle Speed Sensor) — vehicle speed signal from the VSS; pulse input to the ECM used for speed-density calculations and speed-limiting logic.
- B43 (VTA — Throttle Position Sensor) — analogue voltage proportional to throttle opening; 0 V at closed throttle rising to approximately 5 V at wide-open throttle; supplied from the VC 5 V reference.
- B44 (THW — Engine Coolant Temperature Sensor) — analogue NTC thermistor signal; resistance decreases as coolant temperature rises; used for fuelling enrichment and cold-start behaviour.
- B45 (THA — Intake Air Temperature Sensor) — analogue NTC thermistor signal for inlet air temperature; used for air-density compensation in fuel and ignition calculations.
- B47 (OX — Primary Oxygen Sensor) — closed-loop lambda signal from the upstream heated exhaust gas oxygen sensor; analogue voltage input used for fuel trim.
- B48 (Secondary O2 Sensor) — signal from the downstream oxygen sensor; used for catalyst monitor diagnostics.
- B57 (IGT — Ignition Control Module) — ignition timing pulse output from ECM to the igniter; duty cycle and timing of the signal determines spark advance angle.
- B62 (MAP Sensor) — manifold absolute pressure analogue signal; used with intake air temperature for engine load calculation.
- B69 (E1 — Power Ground) — ECM signal and power ground reference.