Self diagnosis NISSAN


General information

The engine control system constantly monitors the input signals from the various sensors in the injection system and compares them with defined limit values. If a signal violates these limits, the control unit stores the fault code in the memory.

The diagnostics socket

Earlier models do not have a diagnostics socket. To change mode, turn the potentiometer on the control unit. On more recent models, the diagnostics socket is located to the left under the steering column.

Appearance of the fault codes

The fault codes can be read out on LEDs on the control unit. The red LED shows the number of tens in the code; the green LED shows the number of units in the code.

Ex.

Code 12, one red blink and two green blinks

Fault code list

11

Crankshaft position sensor

12

Air mass meter

13

Coolant temperature sensor

14

Road speed sensor

21

Ignition position signal is missing

22

Fuel pump

23

Idle switch

24

Full throttle switch

31

ECU

33

Lambda sensor

34

Knock sensor

42

Fuel temperature sensor

43

Throttle potentiometer

51

Injection valve

54

AT-signal missing

55

System OK

Autodiagnosis - m/88/92

The fault codes can be read out on the LEDs on the control unit. Nissan autodiagnosis can perform five different tests, known as Modes. It is possible to see the oscillations of the lambda sond, to read fault codes, to check various switches in the system, and so on.

Mode

Ignition

Engine

Function

I

ON

ON

Mixture ratio check, Monitor A*

II

ON

ON

Mixture ratio check, Monitor B*

III

ON

ON

Fault codes

IV

ON

OFF/ON

Switch ON/OFF function check

V

ON

ON

Real-time diagnosis

There are five different autodiagnosis modes. To change mode, turn a potentiometer on the control unit.

Mode I

Mixture ratio check, Monitor A*

Mode II

Mixture ratio check, Monitor B*

Mode III

Fault codes

Mode IV

Switch ON/OFF function check

Mode V

Real-time diagnosis

* Mode I and II only on cars with catalytic converter and lambda sond

Changing mode

1.

Switch on the ignition or start the engine

2.

Turn the potentiometer fully clockwise

3.

When the diodes have blinked the correct number of times, turn the potentiometer fully counter-clockwise

(One blink for Mode I, two blinks for Mode II, etc.)

Changing mode

NOTE: When the ignition is switched off, the control unit exits autodiagnosis.

Changing mode

1.

Switch on the ignition

2.

Connect a jumper between IGN and CHK in the diagnostics socket for at least two seconds

3.

Remove the jumper. Autodiagnosis is now in Mode I

4.

Connect a jumper between IGN and CHK in the diagnostics socket for at least two seconds

5.

Remove the jumper. Autodiagnosis is now in Mode II

NOTE: When the ignition is switched off, the control unit exits autodiagnosis.

Mode I - m/88-92

Mixture ratio check, Monitor A

Shows the alternations of the lambda sond between lean and rich signal.

1.

Switch on the ignition

2.

Set the autodiagnosis to Mode I (1 blink)

3.

Start the engine

4.

Observe the green LED on the control unit

5.

The LED should blink regularly when the engine is warm

6.

Switch off the ignition

The lambda sond in an open circuit

- The LED remains lit or unlit

The lambda sond in a closed circuit

- The LED should blink regularly with the oscillations of the lambda sond

- LED lit for lean mixture

- LED unlit for rich mixture

Mode II - m/88-92

Mixture ratio check, Monitor B

Shows how the control unit adapts the fuel-air mixture, known as the adaptation.

1.

Switch on the ignition

2.

Set the autodiagnosis to Mode II (two blinks)

3.

Start the engine

4.

Observe the red LED on the control unit

5.

The LED should blink regularly and at the same time as the green LED when the engine is warm

6.

Switch off the ignition

The lambda sond in an open circuit

- The LEDs remain lit or unlit

The lambda sond in a closed circuit

- The LED should blink regularly in time with the green LED

- LED lit for over-lean mixture

- LED unlit for over-rich mixture

Mode III - m/88-92

Autodiagnosis blink codes

The fault codes can be read out on LEDs on the control unit. The red LED shows the number of tens; the green LED shows the number of units.

1.

Start the engine

2.

Set the autodiagnosis to Mode III (three blinks)

3.

Observe the LEDs on the control unit

4.

Switch off the ignition

Code 55 means that there are no faults stored in the control unit.

Mode IV - m/88-92

ON/OFF function check of switches

Check the idling contact, the start signal and the speed sensor.

1.

Switch on the ignition

2.

Set the autodiagnosis to Mode IV (four blinks)

3.

Press the accelerator pedal - The red LED lights up

4.

Start the engine - The red LED lights up

5.

Jack up the car and drive faster than 20 km/h - The green LED lights up

6.

Switch off the ignition

Mode V - m/88-92

Real-time diagnosis, driving test

Monitors the crankshaft sensor, ignition pulses and air volume meter in service.

1.

Start the engine

2.

Set the autodiagnosis to Mode V (five blinks)

3.

Test-drive the car

4.

The LEDs on the control unit must have been unlit for at least five minutes

5.

Switch off the ignition

Possible faults

Red LED blinking:

Crankshaft position sensor signal faulty

Green LED blinks twice:

Air volume meter signal faulty

Green LED blinks four times:

Ignition pulses faulty

Mode I - m/93 >>

Filament lamp check

1.

Switch on the ignition

2.

Connect a jumper between IGN and CHK in the diagnostics socket for at least two seconds

3.

Remove the jumper. Autodiagnosis is now in Mode I Filament lamp check

4.

Check that the engine check lamp is lit *

5.

Switch off the ignition

* If the engine check lamp is not lit, the lamp is faulty.

Checking the control unit

1.

Switch on the ignition

2.

Connect a jumper between IGN and CHK in the diagnostics socket for at least two seconds

3.

Remove the jumper

4.

Start the engine. Autodiagnosis is now in Mode I Control unit check

5.

Check that the engine check lamp is unlit *

6.

Switch off the ignition

* If the engine check lamp is lit, the control unit is faulty.

Mode II - m/93 >>

Fault codes

1.

Switch on the ignition

2.

Connect a jumper between IGN and CHK in the diagnostics socket for at least two seconds

3.

Remove the jumper

4.

Connect a jumper between IGN and CHK in the diagnostics socket for at least two seconds

5.

Remove the jumper. Autodiagnosis is now in Mode II Fault codes

6.

Read off the fault codes on the engine check lamp

7.

Switch off the ignition

Fault code listNissan_Felkodslista93

Mixture ratio check

1.

Switch on the ignition

2.

Connect a jumper between IGN and CHK in the diagnostics socket for at least two seconds

3.

Remove the jumper

4.

Connect a jumper between IGN and CHK in the diagnostics socket for at least two seconds

5.

Remove the jumper

6.

Start the engine. Autodiagnosis is now in Mode II Mixture ratio check

 

Check that the engine check lamp blinks regularly *

7.

Switch off the ignition

* With the engine warm and running at 2000 rpm, the engine check lamp must flash at least five times per 10 seconds

Erase fault codes

Correct any faults in the system before deleting the fault codes.

The fault codes are erased automatically Mode IV or V has been performed.

The diagnostics socket

Earlier models do not have a diagnostics socket. To change mode, turn the potentiometer on the control unit. On more recent models, the diagnostics socket is located to the left under the steering column.

Erase fault codes

1.

Read the fault codes in Mode II

2.

Do not turn of the ignition

3.

Put a jumper between IGN and CHK for min 2 seconds

4.

Release the loop and the fault codes are erased

Autodiagnosis - m/93 >>

There are two different autodiagnosis modes. Each mode has two different states, depending on whether or not the engine is running. The mode is changed by connecting a jumper between IGN and CHK in the diagnostics socket.

Mode I

Filament lamp check / Control unit check

Mode II

Fault codes / Mixture ratio check

Appearance of the fault codes

The fault codes can be read out on the engine check lamp on the instrument panel or on the red LED on the control unit. The long blinks (0.6 s) show the number of tens in the code; the short blinks (0.3 s) show the number of units in the code.

Ex.

0.6s 0.6s 0.6s 0.9s 0.3s 0.3s 0.3s 0.3s 0.3s

Code 23, two long blinks and three short blinks

Fault code list

11

Crankshaft position sensor

12

Air mass meter

13

Coolant temperature sensor

14

Road speed sensor

21

Ignition position signal missing

22

Fuelpump

23

Idle switch

24

Full throttle switch

31

ECU

33

Lambda sensor

34

Knock sensor

42

Fuel temperature sensor

43

Throttle potentiometer

51

Injection valve

54

AT-signal missing

55

System OK