Fuel NISSAN PATROL 1998 Y61 / 5.G Engine Control Repair Manual

Governor Cut Circuit
ON BOARD DIAGNOSIS LOGIC
This diagnostic procedure checks whether or not fuel cut is being performed during deceleration.
Signals from the accelerator switch and camshaft position sensor (PUMP) are sent to the ECM. The ECM uses
these signals to control the electric governor operation.
Accelerator switch (F/C)cAccelerator position
ECM
cElectric
governor
Camshaft position sensor (PUMP)cEngine speed
Diagnostic
Trouble Code
No.Malfunction is detected when ....Check Item
(Possible Cause)
48+Accelerator switch circuit is shorted.
+Crankshaft position sensor (PUMP) or ECM is mal-
functioning.+Harness or connectors
[Accelerator switch (F/C) and camshaft position sen-
sor (PUMP) circuits]
+Accelerator switch (F/C)
+Camshaft position sensor (PUMP)
+ECM
DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE
Note: If both DTC 48 and 11 or 23 are displayed, perform
TROUBLE DIAGNOSIS FOR DTC 11 or 23 (See EC-69 or
106).
1) Turn ignition switch ``ON''.
2) Select ``DATA MONITOR'' mode with CONSULT.
3) Start engine and run it to 3,000 rpm, then quickly release
accelerator pedal.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Start engine and run it to 3,000 rpm, then quickly release
accelerator pedal.
2) Turn ignition switch ``OFF'', wait at least 5 seconds and
then turn ``ON''.
3) Perform ``Diagnostic Test Mode II (Self-diagnostic
results)''.
TROUBLE DIAGNOSIS FOR ``GOV CUT CIRCUIT'' (DTC 48)
EC-149

DIAGNOSTIC PROCEDURE
INSPECTION START
Check fuel level, fuel supplying system,
starter motor, etc.
OK
cNG
Correct.
Check that all glow plug connecting plate
nuts are installed properly.
OK
cNG
Install properly.
CHECK OVERALL FUNCTION.
Check entire glow control system. (Refer
to ``System Operation Check'' on next
page.)
NG
cOK
CHECK COMPONENT
(Glow plug).
See page EC-155.
CHECK VOLTAGE BETWEEN GLOW
RELAY AND GROUND.
1. Turn ignition switch ``OFF''.
2. Disconnect glow relay.
3. Check voltage between terminals
V1,
V3and ground with CONSULT or
tester.
Voltage: Battery voltage
OK
cNG
Check the following.
+100A fusible link
+Harness for open or
short between glow
relay and battery
If NG, repair harness or
connectors.
CHECK OUTPUT SIGNAL CIRCUIT.
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM
terminal
111and terminalV2.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
+Harness connectors
E127,M21
+Harness connectors
M51,F6
+Harness for open or
short between glow
relay and ECM
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
CHECK HARNESS CONTINUITY
BETWEEN GLOW RELAY AND GLOW
PLUG.
1. Disconnect glow plug harness connec-
tor.
2. Check harness continuity between glow
relay terminal
V5and glow plug har-
ness connector.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
+Harness connectors
E65,E204
+Harness for open or
short between glow
relay and glow plug
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
jA
SEF698V
SEF699V
SEF777V
SEF778V
SEF779V
.
.
.
.
.
.
.
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
Glow Control System (Cont'd)
EC-153

ADJUSTMENT RESISTOR
Resistance [at 25ÉC (77ÉF)] kW0.2 - 15.0
INJECTION TIMING CONTROL VALVE
Resistance [at 20ÉC (68ÉF)]WApproximately 11
ELECTRIC GOVERNOR
Resistance [at 23ÉC (73ÉF)]W0.68
CRANKSHAFT POSITION SENSOR (TDC)
Resistance [at 25ÉC (77ÉF)] kWApproximately 0.8 - 1.2
GLOW PLUG
Resistance [at 25ÉC (77ÉF)]W0.8
ACCELERATOR POSITION SENSOR
Throttle valve conditionsResistance kW
[at 25ÉC (77ÉF)]
Completely closed Approximately 0.5
Partially open 0.5 - 4
Completely open Approximately 4
FUEL TEMPERATURE SENSOR
Temperature ÉC (ÉF) Resistance kW
þ20 (þ4) 13.67 - 16.37
20 (68) 2.306 - 2.568
60 (140) 0.538 - 0.624
80 (176) 0.289 - 0.344
SERVICE DATA AND SPECIFICATIONS (SDS)
Inspection and Adjustment (Cont'd)
EC-190