check engine light NISSAN PATROL 1998 Y61 / 5.G Engine Control Workshop Manual

Malfunction Indicator Lamp (MIL)
1. The malfunction indicator lamp will light up when the ignition
switch is turned ON without the engine running. This is a bulb
check.
+If the malfunction indicator lamp does not light up, refer to EL
section (``WARNING LAMPS AND CHIME'') or see EC-188.
2. When the engine is started, the malfunction indicator lamp
should go off.
If the lamp remains on, the on board diagnostic system has
detected an engine system malfunction.
If MIL illuminates or blinks irregularly after starting engine,
water may have accumulated in fuel ®lter. Drain water from
fuel ®lter.
ON BOARD DIAGNOSTIC SYSTEM FUNCTION
The on board diagnostic system has the following three functions.
1. BULB CHECK : This function checks the MIL bulb for damage (blown, open circuit,
etc.).
2. 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.
3. SELF-DIAGNOSTIC
RESULTS: This function allows diagnostic trouble codes to be read.
Refer to ``HOW TO SWITCH DIAGNOSTIC TEST MODES'' on next page.
ConditionDiagnostic
Test Mode IDiagnostic
Test Mode II
Ignition switch
in ``ON'' posi-
tion
Engine
stopped
BULB CHECKSELF-DIAGNOSTIC
RESULTS
Engine
running
MALFUNCTION
WARNINGÐ
SEF051P
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
EC-31

Accelerator Switch (F/C)
The accelerator switch is installed to the accelerator pedal assem-
bly. The switch senses accelerator position and sends an ON-OFF
signal to the ECM. The ECM uses the signal to control the fuel cut
operation at deceleration for better fuel efficiency.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SW (FC)+Ignition switch: ON
(Engine stopped)Accelerator pedal: released CLOSE
Accelerator pedal: slightly open OPEN
DECELER F/CUT+Engine: After warming upIdle OFF
When accelerator pedal is
released quickly with engine
speed at 3,000 rpm or more.ON
ECM TERMINALS AND REFERENCE VALUE
Remarks: Speci®cation data are reference values and are measured between each terminal andV43(ECCS
ground) with a voltmeter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
29 R/L Accelerator switch (F/C)Ignition switch ``ON''
Accelerator pedal fully releasedBATTERY VOLTAGE
(11 - 14V)
Ignition switch ``ON''
Accelerator pedal depressedApproximately 0V
ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble Code
No.Malfunction is detected when ....Check Items
(Possible cause)
23+The OFF signal (short) is sent to the ECM for a cer-
tain period of time even when the accelerator pedal is
not being depressed.+Harness or connectors
(The switch circuit is shorted.)
+Accelerator switch (F/C)
SEF687V
TROUBLE DIAGNOSIS FOR ``ACCEL POS SW (F/C)'' (DTC 23)
EC-106