Nissan Silvia. Manual - part 130

Malfunction Indicator Lamp (MIL)

DESCRIPTION

NMEC0032

SAT652J

The MIL is located on the instrument panel.
1. The MIL will light up when the ignition switch is turned ON without the engine running. This is a bulb check.

If the MIL does not light up, refer to EL-73, WARNING LAMPS or see EC-224.

2. When the engine is started, the MIL should go off.

If the MIL remains on, the on board diagnostic system has detected an engine system malfunction.

On Board Diagnostic System Function

NMEC0032S01

The on board diagnostic system has the following four functions.

Diagnostic Test
Mode

KEY and ENG.
Status

Function

Explanation of Function

Mode I

Ignition switch in
ON position

Engine stopped

BULB CHECK

This function checks the MIL bulb for damage (blown,
open circuit, etc.).
If the MIL does not come on, check MIL circuit. (See
EC-224.)

Engine running

MALFUNCTION
WARNING

This is a usual driving condition. When a malfunction is
detected, the MIL will light up to inform the driver that a
malfunction has been detected.

Mode II

Ignition switch in
ON position

Engine stopped

SELF-DIAGNOSTIC RESULTS

This function allows DTCs to be read.

Engine running

HEATED OXYGEN SENSOR 1
(FRONT) MONITOR

This function allows the fuel mixture condition (lean or
rich), monitored by heated oxygen sensor 1 (front), to be
read.

MIL Flashing without DTC

NMEC0032S0102

If the ECM is in Diagnostic Test Mode II, MIL may flash when engine is running. In this case, check ECM
diagnostic test mode following “How to Switch Diagnostic Test Modes”, EC-36.
How to switch the diagnostic test (function) modes, and details of the above functions are described later.
(Refer to EC-37.)

IDX

ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION

Malfunction Indicator Lamp (MIL)

EC-35

How to Switch Diagnostic Test Modes

NMEC0032S07

SEC330C

EC-224

EC-35

EC-224

ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION

Malfunction Indicator Lamp (MIL) (Cont’d)

EC-36

Diagnostic Test Mode I — Bulb Check

NMEC0032S03

In this mode, the MIL on the instrument panel should stay ON. If it remains OFF, check the bulb. Refer to
EL-73, “WARNING LAMPS” or see EC-224.

Diagnostic Test Mode I — Malfunction Warning

NMEC0032S04

MIL

Condition

When malfunction is detected.

OFF

No malfunction.

Diagnostic Test Mode II — Self-diagnostic Results

NMEC0032S08

In this mode, the DTC is indicated by the number of blinks of the MIL.
A DTC will be used as an example for how to read a code.

SEC375C

Long (0.6 second) blinking indicates the number of 1000th and 100th digits, and short (0.3 second) blinking
indicates the number of tenth and single digits.
For example, the malfunction indicator lamp blinks four times for about 2.5 seconds (0.6 sec x 4 times) and
then it blinks three times for about 1 second (0.3 sec x 3 times). This indicates the DTC “0403” and refers to
the malfunction of the throttle position sensor.
In this way, all the detected malfunctions are classified by their diagnostic trouble code numbers. The DTC
“0505” refer to no malfunction. (See TROUBLE DIAGNOSIS — INDEX, EC-4.)
How to Erase Diagnostic Test Mode II (Self-diagnostic results)

NMEC0032S0801

The DTC can be erased from the backup memory in the ECM when the diagnostic test mode is changed from
Diagnostic Test Mode II to Diagnostic Test Mode I. (Refer to “How to Switch Diagnostic Test Modes”, EC-36.)

If the battery is disconnected, the DTC will be lost from the backup memory after approx. 24 hours.

Be careful not to erase the stored memory before starting trouble diagnoses.

IDX

ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION

Malfunction Indicator Lamp (MIL) (Cont’d)

EC-37

Diagnostic Test Mode II — Heated Oxygen Sensor 1 (Front) Monitor

=NMEC0032S09

In this mode, the MIL displays the condition of the fuel mixture (lean or rich) which is monitored by the heated
oxygen sensor 1 (front).

MIL

Fuel mixture condition in the exhaust gas

Air fuel ratio feedback control condition

Lean

Closed loop system

OFF

Rich

*Remains ON or OFF

Any condition

Open loop system

*: Maintains conditions just before switching to open loop.

To check the heated oxygen sensor 1 (front) function, start engine in the Diagnostic Test Mode II and warm
it up until engine coolant temperature indicator points to the middle of the gauge.
Next run engine at about 2,000 rpm for about 2 minutes under no-load conditions. Then make sure that the
MIL comes ON more than 5 times within 10 seconds with engine running at 2,000 rpm under no-load.

ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION

Malfunction Indicator Lamp (MIL) (Cont’d)

EC-38

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