1998 NISSAN PATROL Engine Control Workshop Manual

COMPONENT INSPECTION
Accelerator position sensor
1. Disconnect accelerator position sensor harness connector.
2. Make sure that resistance between terminals
V2andV3
changes when depressing accelerator pedal manually.
Accelerator pedal conditions Resistance [at 25ÉC (77ÉF)]
Completely released Approximately 0.5 kW
Partially depressed 0.5-4kW
Completely depressed Approximately 4 kW
If NG, replace accelerator pedal assembly.
CAUTION:
If accelerator position sensor or ECM connector is
disconnected, perform the following procedures:
Select ``OFF ACCEL PO SIG'' in ``ACTIVE TEST'' mode.
Touch CLEAR.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Start and warm up engine. After engine has warmed up,
idle for 10 minutes.
SEF695V
TROUBLE DIAGNOSIS FOR ``ACCEL POS SENSOR'' (DTC 43)
Accelerator Position Sensor (Cont'd)
EC-143

Crankshaft Position Sensor (TDC)
The crankshaft position sensor (TDC) monitors engine speed by
means of signals from the sensing plate (with two protrusions)
installed to the crankshaft pulley. The datum signal output is
detected at ATDC 70É and sent to the ECM. The sensor signal is
used for fuel injection control and fuel injection timing control.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
CKPSzRPM (TDC)+Tachometer: Connect
+Run engine and compare tachometer indication with the CONSULT
value.Almost the same speed as the
CONSULT value.
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)
40
44LCrankshaft position sensor
(TDC)Engine is running.
(Warm-up condition)
Idle speedApproximately 0V
SEF720V
Engine is running.(Warm-up condition)
Engine speed is 2,000 rpm.Approximately 0V
SEF721V
47
52B/WCrankshaft position sensor
(TDC) groundEngine is running.(Warm-up condition)
Idle speedApproximately 0V
ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble Code
No.Malfunction is detected when ....Check Items
(Possible Cause)
47+An improper signal from the sensor is detected by
ECM during engine running and cranking.+Harness or connectors
(The sensor circuit is open.)
+Crankshaft position sensor (TDC)
SEF615S
TROUBLE DIAGNOSIS FOR ``CRANK POS SEN (TDC)'' (DTC 47)
EC-144

DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE
Before performing the following procedure, con®rm that bat-
tery voltage is more than 10V.
1) Turn ignition switch ``ON'' and select ``DATA MONITOR''
mode with CONSULT.
2) Crank engine for at least 1 second.
3) Start engine and run it for at least 2 seconds at idle
speed.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Crank engine for at least 1 second.
2) Start engine and run it for at least 2 seconds at idle
speed.
3) Turn ignition switch ``OFF'', wait at least 5 seconds and
then turn ``ON''.
4) Perform ``Diagnostic Test Mode II (Self-diagnostic
results)'' with ECM.SEF714V
TROUBLE DIAGNOSIS FOR ``CRANK POS SEN (TDC)'' (DTC 47)
Crankshaft Position Sensor (TDC) (Cont'd)
EC-145

TEC437
TROUBLE DIAGNOSIS FOR ``CRANK POS SEN (TDC)'' (DTC 47)
Crankshaft Position Sensor (TDC) (Cont'd)
EC-146

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK INPUT SIGNAL CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Disconnect crankshaft position sensor
(TDC) harness connector and ECM har-
ness connector.
3. Check harness continuity between ECM
terminals
V40,V44and terminalV1.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
+Harness connectors
F13,EC4+Harness for open or
short between ECM and
crankshaft position sen-
sor (TDC)
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
CHECK GROUND CIRCUIT-I.
Check harness continuity between termi-
nal
V2and ECM terminalsV47,V52.
Continuity should exist.
If OK, check harness for short to ground
and short to power.
OK
cNG
Check the following.
+Harness connectors
F13,EC4+Harness for open or
short between crankshaft
position sensor (TDC)
and ECM
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
CHECK GROUND CIRCUIT-II.
1. Loosen and retighten engine ground
screws.
2. Disconnect harness connectors
F13,EC4.
3. Check harness continuity between ter-
minal
V3and engine ground.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
+Joint connector
F19+Harness for open or
short between harness
connector
F13and
engine ground
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
CHECK COMPONENT
[Crankshaft position sensor (TDC)].
Refer to ``COMPONENT INSPECTION''
on next page.
OK
cNG
Replace crankshaft posi-
tion sensor (TDC).
Disconnect and reconnect harness connec-
tors in the circuit. Then retest.
Trouble is not ®xed.
Check ECM pin terminals for damage and
check the connection of ECM harness con-
nector. Reconnect ECM harness connector
and retest.
INSPECTION END
SEF696V
SEF774V
SEF775V
SEF676V
SEF776V
.
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``CRANK POS SEN (TDC)'' (DTC 47)
Crankshaft Position Sensor (TDC) (Cont'd)
EC-147

COMPONENT INSPECTION
Crankshaft position sensor (TDC)
1. Disconnect crankshaft position sensor (TDC) harness connec-
tor.
2. Loosen the ®xing bolt of the sensor.
3. Remove the sensor.
4. Visually check the sensor for chipping.
5. Check resistance between terminals
V1andV2.
Resistance: Approximately 0.8 - 1.2 kW
[at 25ÉC (77ÉF)]
If NG, replace crankshaft position sensor (TDC).
SEF620S
SEF697V
TROUBLE DIAGNOSIS FOR ``CRANK POS SEN (TDC)'' (DTC 47)
Crankshaft Position Sensor (TDC) (Cont'd)
EC-148

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
1) Turn ignition switch ``ON''.
2) Select ``SELF DIAG RESULTS''
mode with CONSULT.
3) Touch ``ERASE''.
--------------------------------------------------------------------------------------------------------------------------------------OR--------------------------------------------------------------------------------------------------------------------------------------
1) Turn ignition switch ``ON''.
2) Erase the diagnostic test mode
II (Self-diagnostic results)
memory.
PERFORM DIAGNOSTIC TROUBLE
CODE CONFIRMATION PROCEDURE.
See previous page.
Is the DTC 48 displayed again?
No
cYe s
Replace ECM.
INSPECTION END
.
.
.
.
TROUBLE DIAGNOSIS FOR ``GOV CUT CIRCUIT'' (DTC 48)
Governor Cut Circuit (Cont'd)
EC-150