The ECU - Electronic Control Unit is an embedded system that controls one or more of the electrical systems or subsystems in a vehicle.
ECU - Electronic Control Unit Connector.
The 1995–1997 Nissan 200SX (sold in North America on the B14/N14 platform, excluding the 1997 GA16DE 1.6-litre variant) is controlled by a Nissan ECCS (Electronic Concentrated Control System) engine management unit. ECCS provides sequential multi-point fuel injection and electronically controlled ignition timing from a single ECM. The system supports OBD-I or OBD-II diagnostics depending on production date, with 1996 and later vehicles universally OBD-II compliant. The ECM connector is a multi-pin Nissan-proprietary header consistent with the B13/N14 platform specification.
| Pin | name | Signal |
|---|---|---|
| 3 | Tachometer Signal | RPM |
| 23 | Throttle Position Sensor | Analog |
| 26 | Vehicle Speed Sensor | Speed |
| 33 | Throttle Position Sensor (A/T) | Analog |
| 46 | O2 Sensor Signal (Front) | Analog |
| 47 | Mass Air Flow Sensor | Analog |
| 48 | Mass Air Flow Sensor Ground | Ground |
| 50 | Sensor Ground | Ground |
| 51 | Engine Coolant Temperature Sensor | Analog |
| 52 | O2 Sensor Signal (Rear) | Analog |
| 63 | Intake Air Temperature Sensor | Analog |
| 70 | Power Supply (Aux) | Power |
| 102 | Injector # 1 | Speed |
| 104 | Injector # 3 | Speed |
| 107 | Injector # 2 | Speed |
| 109 | Injector # 4 | Speed |
| 112 | Power Ground (Electronic Concentrated Control System) | Ground |
| 118 | Power Ground (Electronic Concentrated Control System) | Ground |
Notes
The pinout above covers the SR20DE and SR20DET engine variants fitted to the 1995–1997 200SX; it does not apply to the 1997 GA16DE 1.6-litre model. The ECM uses a Nissan-proprietary multi-pin connector; pin numbering follows the factory harness scheme defined in the B13/N14 official factory workshop manual. The ECCS system communicates via the Nissan CONSULT serial diagnostic interface, accessible through the dedicated data link connector in the vehicle.
Signals
- Tachometer Signal — engine speed output from ECM to instrument cluster (RPM)
- Throttle Position Sensor — analogue voltage signal from TPS indicating throttle blade angle
- Vehicle Speed Sensor — vehicle speed pulse signal input to ECM
- Throttle Position Sensor (A/T) — secondary TPS signal used by the automatic transmission control circuit
- O2 Sensor Signal (Front) — analogue voltage from the upstream (pre-catalyst) heated oxygen sensor
- Mass Air Flow Sensor — analogue voltage from the hot-wire MAF sensor indicating intake air mass
- Mass Air Flow Sensor Ground — dedicated signal ground for the MAF sensor
- Sensor Ground — common reference ground for analogue sensor inputs
- Engine Coolant Temperature Sensor — analogue NTC thermistor signal for coolant temperature
- O2 Sensor Signal (Rear) — analogue voltage from the downstream (post-catalyst) oxygen sensor for catalyst monitor
- Intake Air Temperature Sensor — analogue NTC thermistor signal for intake air temperature
- Power Supply (Aux) — auxiliary power supply to ECM
- Injector #1 — low-side drive signal to fuel injector cylinder 1
- Injector #3 — low-side drive signal to fuel injector cylinder 3
- Injector #2 — low-side drive signal to fuel injector cylinder 2
- Injector #4 — low-side drive signal to fuel injector cylinder 4
- Power Ground (ECCS) — main power ground for the Electronic Concentrated Control System (pin 112)
- Power Ground (ECCS) — additional power ground for the Electronic Concentrated Control System (pin 118)