1998 NISSAN PATROL Engine Control Workshop Manual

Fuel Temperature Sensor (FTS)
The fuel temperature sensor is used to detect the fuel temperature
in the injection pump. The sensor modi®es a voltage signal from the
ECM. The modi®ed signal returns to the ECM as the fuel tempera-
ture input. The sensor uses a thermistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.

Engine coolant tempera-
ture
ÉC (ÉF)Voltage
(V)Resistance
(kW)
þ20 (þ4) 4.6 13.67 - 16.37
20 (68) 3.5 2.306 - 2.568
60 (140) 1.8 0.538 - 0.624
80 (176) 1.2 0.289 - 0.344
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)
10 P Fuel temperature sensor Engine is running.
Approximately 0 - 4.8V
Output voltage varies with
fuel temperature.
50 B Sensors' 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)
42+An excessively high or low voltage from the sensor is
detected by ECM.+Harness or connectors
(The sensor circuit is open or shorted.)
+Fuel temperature sensor
DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE
1) Turn ignition switch ``ON''.
2) Select ``DATA MONITOR'' mode with CONSULT.
3) Wait at least 5 seconds.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Turn ignition switch ``ON'' and wait at least 5 seconds.
2) Turn ignition switch ``OFF'', wait at least 5 seconds and
then turn ``ON''.
3) Perform ``Diagnostic Test Mode II (Self-diagnostic
results)'' with ECM.
SEF666S
SEF012P
SEF748V
TROUBLE DIAGNOSIS FOR ``FUEL TEMP SENSOR'' (DTC 42)
EC-135

TEC435
TROUBLE DIAGNOSIS FOR ``FUEL TEMP SENSOR'' (DTC 42)
Fuel Temperature Sensor (FTS) (Cont'd)
EC-136

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK POWER SUPPLY.
1. Turn ignition switch ``OFF''.
2. Disconnect electronic fuel injection
pump harness connector.
3. Turn ignition switch ``ON''.
4. Check voltage between terminal
V1
and ground with CONSULT or tester.
Voltage:
Approximately 5V
OK
cNG
Repair harness or connec-
tors.
CHECK GROUND CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Check harness continuity between ter-
minal
V5and engine ground.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
+Harness connectors
F6,M51
+Harness connectors
M88,E106
+Harness for open or
short between ECM and
electronic fuel injection
pump
+Harness for open or
short between TCM and
electronic fuel injection
pump
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
CHECK COMPONENT
(Fuel temperature sensor).
Refer to ``COMPONENT INSPECTION''
on next page.
OK
cNG
Take proper action.
Disconnect and reconnect harness con-
nectors in the circuits. Then retest.
Trouble is not ®xed.
Check ECM pin terminals for damage and
check the connection of ECM harness
connector. Reconnect ECM harness con-
nector and retest.
INSPECTION END
SEF682VB
SEF769V
SEF770V
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``FUEL TEMP SENSOR'' (DTC 42)
Fuel Temperature Sensor (FTS) (Cont'd)
EC-137

COMPONENT INSPECTION
Fuel temperature sensor
Wait until fuel temperature sensor reaches room temperature.
Check resistance as shown in the ®gure.
Temperature ÉC (ÉF) Resistance kW
20 (68) 2.306 - 2.568
60 (140) 0.538 - 0.624
80 (176) 0.289 - 0.344
If NG, take proper action.SEF693V
SEF012P
TROUBLE DIAGNOSIS FOR ``FUEL TEMP SENSOR'' (DTC 42)
Fuel Temperature Sensor (FTS) (Cont'd)
EC-138

Accelerator Position Sensor
The accelerator position sensor is installed on the upper end of the
accelerator pedal assembly. The sensor detects the accelerator
position and sends a signal to the ECM. The ECM uses the signal
to determine the amount of fuel to be injected.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
ACCEL POS SEN+Ignition switch: ON
(Engine stopped)Accelerator pedal: released 0.40 - 0.60V
Accelerator pedal: depressed Approx. 4.0V
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)
23 WAccelerator position sen-
sorIgnition switch ``ON''
Accelerator pedal fully released0.4 - 0.6V
Ignition switch ``ON''
Accelerator pedal fully depressedApproximately 4.3V
48 G/RAccelerator position sen-
sor power supplyIgnition switch ``ON''
Approximately 5V
51 L/WAccelerator position sen-
sor groundEngine is running.
(Warm-up condition)
Idle speedApproximately 0V
SEF861SA
TROUBLE DIAGNOSIS FOR ``ACCEL POS SENSOR'' (DTC 43)
EC-139

ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble
Code No.Malfunction is detected when ...Check Items
(Possible Cause)
43+An excessively low or high voltage from the sensor is
detected by the ECM.+Harness or connectors
(The sensor circuit is open or shorted.)
+Accelerator position sensor
+Accelerator position switch
+Accelerator switch (F/C)
DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE
1) Turn ignition switch ``ON''.
2) Select ``DATA MONITOR'' mode with CONSULT.
3) Wait at least 2 seconds.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Turn ignition switch ``ON'' and wait at least 2 seconds.
2) Turn ignition switch ``OFF'', wait at least 5 seconds and
then turn ``ON''.
3) Perform ``Diagnostic Test Mode II (Self-diagnostic
results)'' with ECM.
SEF748V
TROUBLE DIAGNOSIS FOR ``ACCEL POS SENSOR'' (DTC 43)
Accelerator Position Sensor (Cont'd)
EC-140

TEC436
TROUBLE DIAGNOSIS FOR ``ACCEL POS SENSOR'' (DTC 43)
Accelerator Position Sensor (Cont'd)
EC-141

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK POWER SUPPLY.
1. Turn ignition switch ``OFF''.
2. Disconnect accelerator position sensor
harness connector.
3. Turn ignition switch ``ON''.
4. Check voltage between terminal
V1and ground with CONSULT or tester.
Voltage: Approximately 5V
OK
cNG
Check the following.
+Harness connectors
F7,M52(RHD mod-
els)
+Harness for open or
short between ECM and
accelerator position sen-
sor
If NG, repair harness or
connectors.
CHECK GROUND CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Loosen and retighten engine ground
screw.
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.
+Harness connectors
F7,M52(RHD mod-
els)
+Harness for open or
short between ECM and
accelerator position sen-
sor
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
CHECK INPUT SIGNAL CIRCUIT.
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM
terminal
V23and terminalV2.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
+Harness connectors
F7,M52(RHD mod-
els)
+Harness for open or
short between ECM and
accelerator position sen-
sor
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
CHECK COMPONENT
(Accelerator position sensor).
Refer to ``COMPONENT INSPECTION''
on next page.
OK
cNG
Replace accelerator pedal
assembly.
Disconnect and reconnect harness con-
nectors in the circuit. Then retest.
Trouble is not ®xed.
Check ECM pin terminals for damage and
check the connection of ECM harness
connector. Reconnect ECM harness con-
nector and retest.
INSPECTION END
SEF694V
SEF771V
SEF676V
SEF772V
SEF773V
.
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``ACCEL POS SENSOR'' (DTC 43)
Accelerator Position Sensor (Cont'd)
EC-142