The 1991–1993 Nissan NX (sold as the NX1600 and NX2000) shares its B13/N14 platform with the contemporary Sentra and 100NX. The engine management system is Nissan ECCS (Electronic Concentrated Control System), a sequential multi-point fuel injection and electronic ignition system controlled by a single ECM. The NX1600 uses the 1.6 L DOHC GA16DE and the NX2000 uses the 2.0 L DOHC SR20DE; both variants employ a 76-pin ECM connector. The system uses OBD-I diagnostics accessible via the ECM self-diagnostic mode on these model years.
ECU - Electronic Control Unit Connector.
| Pin | name | Signal |
|---|---|---|
| 2 | Tachometer Signal | RPM |
| 16 | Mass Air Flow Sensor | Analog |
| 17 | Mass Air Flow Sensor Ground | Ground |
| 18 | Engine Coolant Temperature Sensor | Analog |
| 19 | O2 Sensor Signal | Analog |
| 20 | Throttle Position Sensor | Analog |
| 21 | Sensor Ground | Ground |
| 26 | Air Temperature Sensor | Analog |
| 32 | Vehicle Speed Sensor | Speed |
| 48 | Power Ground (Electronic Concentrated Control System) | Ground |
| 101 | Injector # 1 | Speed |
| 103 | Injector # 3 | Speed |
| 110 | Injector # 2 | Speed |
| 112 | Injector # 4 | Speed |
| 116 | Power Ground (Electronic Concentrated Control System) | Ground |
Notes
The ECM connector on the B13/N14 platform is a 76-pin Nissan proprietary multi-pin header. Only the pins with documented functions are listed above; remaining positions are either unpopulated or serve functions not covered by this partial listing. The GA16DE and SR20DE share the same physical connector housing on this platform; pin assignments may differ between engine variants. Diagnostics are OBD-I: fault codes are retrieved via the ECM self-diagnostic LED or the Nissan CONSULT serial interface.
Signals
- Tachometer Signal — engine speed (RPM) output from the ECM to the instrument cluster
- Mass Air Flow Sensor — analogue voltage input from the hot-wire MAF sensor measuring intake air mass
- Mass Air Flow Sensor Ground — dedicated signal ground return for the MAF sensor circuit
- Engine Coolant Temperature Sensor — analogue voltage input from the NTC coolant temperature sensor
- O2 Sensor Signal — analogue voltage input from the upstream exhaust oxygen sensor for closed-loop fuelling
- Throttle Position Sensor — analogue voltage input from the TPS indicating throttle blade angle
- Sensor Ground — common signal ground reference for multiple sensor circuits
- Air Temperature Sensor — analogue voltage input from the intake air temperature sensor
- Vehicle Speed Sensor — pulse signal input from the transmission-mounted vehicle speed sensor
- Power Ground (Electronic Concentrated Control System) — main power ground for the ECCS ECM (pin 48)
- Injector #1 — drive signal output controlling fuel injector 1
- Injector #3 — drive signal output controlling fuel injector 3
- Injector #2 — drive signal output controlling fuel injector 2
- Injector #4 — drive signal output controlling fuel injector 4
- Power Ground (Electronic Concentrated Control System) — second main power ground for the ECCS ECM (pin 116)