Nissan OBD / OBD2 Codes >> Axxess – Pickup – Pickup/Pathfinder – Pulsar 1.6/1.8L – Sentra 1.6L (1988 – 1995)

ModeLYearEngine identificationSystem
Axxess  2.4L1990KA24E  ECCS
Pickup 2.4L1990-95KA24E  ECCS
Pickup/Pathfinder 3.0L1990-95VG30E  ECCS
Pulsar 1.6L1988-90E16i/GA16i  ECCS
Pulsar 1.8L1988-89CA18DE  ECCS
Sentra  1.6L1988-90E16i/GA16i  ECCS

General information

  • Engine control module (ECM) incorporates self-diagnosis function.
  • Malfunction indicator lamp (MIL) will illuminate if certain faults are recorded – California 1988 on.
  • ECM operates in backup mode if certain sensors fail, to enable vehicle to be driven to workshop.
  • Trouble codes are displayed by the red and green LED’s in the engine control module (ECM), in diagnostic test mode 3, or using a suitable code reader.
  • The red LED flashes indicate ‘tens’, followed by the green which indicate ‘units’.


Mode selection

  • Access engine control module (ECM):
o Sentra/Pulsar – 1.
o Axxess- 2
o Pickup/Pathfinder – 3.
  • Switch ignition ON.
  • Turn ECM diagnosis mode selector fully clockwise 4 [1] .
  • Wait until the LED’s flash [4] [2].
  • After LED’s flash required mode number, turn mode selector fully counterclockwise [4] [1].
  • For example 3 flashes indicates Mode 3.
NOTE: If the ignition is switched OFF during self-diagnosis, the ECM will return to mode 1 when it is turned ON again.

Mode description

  • Mode 1: Mixture ratio feedback – heated oxygen sensor (H02S)/oxygen sensor (02S).
  • Mode 2: Mixture ratio feedback – CO adjustment section.
  • Mode 3: Code display.
  • Mode 4: Tests diagnosis ON/OFF switching.
  • Mode 5: Real time diagnosis, codes displayed as they occur.

Mode 3

  • Access engine control module (ECM).
  • Switch ignition ON. Do NOT start engine.
  • Select mode 3.
  • Count LED flashes and compare with trouble code table.

Mode 4

  • Access engine control module (ECM).
  • Switch ignition ON. Do NOT start engine.
  • Select mode 4.
  • Red LED goes off.
  • Crank engine, red LED should come ON.
  • Depress accelerator pedal, red LED goes OFF.
  • Raise driven wheels of vehicle and drive vehicle, green LED should come ON when speed reaches 12 mph (20 kph).

Mode 5

  • Access engine control module (ECM).
  • Start engine.
  • Select mode 5.
  • Test drive vehicle.
  • LED’s will flash any codes occurring during test.


NOTE: Trouble codes are automatically erased once the starter is operated 50 times after the last trouble code was stored.

Method 1

  • Select mode 3.
  • Read flash codes.
  • Select mode 4.
  • Switch ignition OFF.

Method 2

  • Ensure ignition switched OFF.
  • Disconnect battery ground cable.
  • Wait at least 15 seconds.
  • Reconnect battery ground cable.
  • Repeat checking procedure to ensure no data remains in ECM fault memory.

NOTE: Disconnecting battery ground lead may also erase memory from electronic units such as radio.

Trouble code  identification

Flash code

Fault location

Probable cause


Crankshaft position (CKP) sensor- circuit malfunction

Wiring, CKP sensor, ECM


Mass air flow (MAF) sensor – range/

performance problem

Wiring, MAF sensor, ECM


Engine coolant temperature (ECT) sensor – range/performance problem

Wiring, ECT sensor, ECM


Vehicle speed sensor (VSS) – malfunction

Wiring, VSS, ECM


Injector- mixture lean- 1988

Injector, fuel system, ECM


Ignition coil – no primary signal

Wiring, ignition coil/module, ignition system, ECM


Closed throttle position (CTP) switch – circuit malfunction

Wiring, CTP switch, ECM


Idle air control (lAC) valve – idle speed higher than specified

Wiring, lAC valve, ECM


Engine control module (ECM) – malfunction



Exhaust gas recirculation (EGR) system – control valve malfunction

Wiring, hose leak/blockage, EGR cut OFF

solenoid, ECM


Heated oxygen sensor (H02S)- circuit malfunction

Wiring, H02S, intake/fuel system, injector, ECM


Knock sensor (KS) – circuit malfunction

Wiring, KS, ECM


Exhaust gas recirculation temperature (EGRT)

sensor – circuit malfunction

Wiring, EGRT sensor, ECM


Intake air temperature (IAT) sensor- circuit malfunction

Wiring, IAT sensor, ECM


Throttle position (TP) sensor – circuit malfunction

Wiring, TP sensor, ECM


Injector leak – malfunction

Injector, fuel system, ECM


Injector- circuit malfunction

Wiring, injector, ECM


No faults detected