1998 NISSAN PICK-UP Repair Manual

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK POWER SUPPLY.
1. Turn ignition switch ``OFF''.
2. Disconnect engine coolant temperature
sensor harness connector.
3. Turn ignition switch ``ON''.
4. Check voltage between terminal
V2
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
V1and engine ground.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
lHarness for open or
short between ECM and
engine coolant tempera-
ture sensor
If NG, repair open circuit,
short to ground or short to
power in harness or con-
nectors.
CHECK COMPONENT
(Engine coolant temperature sensor).
Refer to ``COMPONENT INSPECTION''
on next page.
OK
cNG
Replace engine coolant
temperature sensor.
Disconnect and reconnect harness con-
nectors in the circuit. Then retest.
Trouble is not fixed.
Check ECM pin terminals for damage
and check the connection of ECM har-
ness connector. Reconnect ECM harness
connector and retest.
INSPECTION END
SEF083U
SEF645R
SEF646R
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``COOLANT TEMP SEN'' (DTC 13)KA
Engine Coolant Temperature Sensor (ECTS)
(Cont'd)
EC-97

COMPONENT INSPECTION
Engine coolant temperature sensor
Check resistance as shown in the figure.

Temperature ÉC (ÉF) Resistance kW
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
If NG, replace engine coolant temperature sensor.
SEF152P
SEF012P
TROUBLE DIAGNOSIS FOR ``COOLANT TEMP SEN'' (DTC 13)KA
Engine Coolant Temperature Sensor (ECTS)
(Cont'd)
EC-98

Ignition Signal
COMPONENT DESCRIPTION
Ignition coil & power transistor (Built into distributor)
The ignition signal from the ECM is sent to and amplified by the
power transistor. The power transistor turns on and off the igni-
tion coil primary circuit. This on-off operation induces the proper
high voltage in the coil secondary circuit.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
IGN TIMING
lEngine: After warming uplAir conditioner switch: ``OFF''lShift lever: Neutral positionlNo-loadIdle 10É BTDC
2,000 rpm More than 25É BTDC
ECM TERMINALS AND REFERENCE VALUE
Remarks: Specification data are reference values, and are measured between each terminal andV39(ECCS ground) with a voltme-
ter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC voltage)
1 W/PU Ignition signalEngine is running.
Idle speedApproximately 0.3V
SEF058U
Engine is running.
Engine speed is 2,000 rpm.Approximately 0.7V
SEF059U
SEF128S
TROUBLE DIAGNOSIS FOR ``IGN SIGNAL-PRIMARY'' (DTC 21)KA
EC-99

TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC voltage)
3 W/G Ignition checkEngine is running.
Idle speedApproximately 13V
SEF062U
Engine is running.
Engine speed is 2,000 rpm.Approximately 13V
SEF063U
ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble
Code No.Malfunction is detected when ...Check Items
(Possible Cause)
21
lThe ignition signal in the primary circuit is not sent
during engine cranking or running.lHarness or connectors
(The ignition primary circuit is open or shorted.)
lPower transistor
lResistor
lCamshaft position sensor
lCamshaft position sensor circuit
DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE
Note: If both DTC 21 and DTC 11 are displayed, perform
TROUBLE DIAGNOSIS FOR DTC 11 first. (See EC-82.)
1) Turn ignition switch ``ON''.
2) Select ``DATA MONITOR'' mode with CONSULT.
3) Start engine and wait at least 2 seconds. (If engine
does not run, turn ignition switch to ``START'' for at
least 5 seconds.)
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Turn ignition switch ``ON''.
2) Start engine and wait at least 2 seconds. (If engine
does not run, turn ignition switch to ``START'' for at
least 5 seconds.)
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.SEF051U
TROUBLE DIAGNOSIS FOR ``IGN SIGNAL-PRIMARY'' (DTC 21)KA
Ignition Signal (Cont'd)
EC-100

LHD MODELS
HEC344
TROUBLE DIAGNOSIS FOR ``IGN SIGNAL-PRIMARY'' (DTC 21)KA
Ignition Signal (Cont'd)
EC-101

RHD MODELS
HEC345
TROUBLE DIAGNOSIS FOR ``IGN SIGNAL-PRIMARY'' (DTC 21)KA
Ignition Signal (Cont'd)
EC-102

DIAGNOSTIC PROCEDURE
INSPECTION START
Turn ignition switch ``OFF'', and restart
engine.
Is engine running?
No
cYes
VA(Go to next page.)
CHECK POWER SUPPLY.
1. Turn ignition switch ``OFF''.
2. Disconnect ignition coil harness con-
nector.
3. Turn ignition switch ``ON''.
4. Check voltage between terminal
V7
and ground with CONSULT or tester.
Voltage: Battery voltage
OK
cNG
Check the following.
lHarness connectorsF55,M47(RHD mod-
els)
lHarness for open or
short between ignition
coil and ignition switch
If NG, repair harness or
connectors.
CHECK GROUND CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Disconnect power transistor harness
connector.
3. Check harness continuity between ter-
minal
V2and engine ground.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Repair open circuit, short
to ground or short to
power in harness or con-
nectors.
CHECK OUTPUT SIGNAL CIRCUIT.
1. Disconnect ECM harness connector.
2. Check harness continuity between
ECM terminal
V1and terminalV1.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Repair open circuit, short
to ground or short to
power in harness or con-
nectors.
CHECK COMPONENTS
(Ignition coil, power transistor).
Refer to ``COMPONENT INSPECTION'',
EC-105.
OK
cNG
Replace malfunctioning
component(s).
Disconnect and reconnect harness con-
nectors in the circuit. Then retest.
Trouble is not fixed.
Check ECM pin terminals for damage
and check the connection of ECM har-
ness connector. Reconnect ECM harness
connector and retest.
INSPECTION END
SEF128S
SEF172S
SEF173S
SEF174S
.
.
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``IGN SIGNAL-PRIMARY'' (DTC 21)KA
Ignition Signal (Cont'd)
EC-103

VA
CHECK INPUT SIGNAL CIRCUIT.
1. Stop engine.
2. Disconnect ignition coil harness con-
nector.
3. Strip tape covering resistor.
4. Disconnect resistor harness connector.
5. Disconnect ECM harness connector.
6. Check harness continuity between ter-
minal
V8and terminalV1, terminal
V2and ECM terminalV3.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Repair open circuit, short
to ground or short to
power in harness or con-
nectors.
CHECK COMPONENT
(Resistor).
Refer to ``COMPONENT INSPECTION''
on next page.
OK
cNG
Replace resistor.
Disconnect and reconnect harness con-
nectors in the circuit. Then retest.
Trouble is not fixed.
Check ECM pin terminals for damage
and check the connection of ECM har-
ness connector. Reconnect ECM harness
connector and retest.
INSPECTION END
SEF084U
AEC125A
SEF085U
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``IGN SIGNAL-PRIMARY'' (DTC 21)KA
Ignition Signal (Cont'd)
EC-104