1998 NISSAN PICK-UP engine

VA
CHECK HARNESS CONTINUITY BETWEEN
ECCS RELAY AND ECM.
1. Disconnect ECM harness connector.
2. Disconnect ECCS relay.
3. Check harness continuity between ECM ter-
minals
V38,V47,109and terminalV5.
Continuity should exist.
If OK, check harness for short to ground and
short to power.
OK
cNG
Check the following.
lHarness connectorsF54,M48(RHD models)lHarness connectorsM5,E101lHarness for open or short
between ECM and ECCS
relay
If NG, repair open circuit,
short to ground or short to
power in harness or connec-
tors.
CHECK VOLTAGE BETWEEN ECCS RELAY
AND GROUND.
Check voltage between terminals
V1,V3and
ground with CONSULT or tester.
Voltage: Battery voltage
OK
cNG
Check the following.
lHarness for open or short
between ECCS relay and
fuse
If NG, repair harness or con-
nectors.
CHECK OUTPUT SIGNAL CIRCUIT.
Check harness continuity between ECM termi-
nal
V4and relay terminalV2.
Continuity should exist.
If OK, check harness for short to ground and
short to power.
OK
cNG
Check the following.
lHarness connectorsF54,M48(RHD models)lHarness connectorsM5,E101lHarness for open or short
between ECM and ECCS
relay
If NG, repair open circuit,
short to ground or short to
power in harness or connec-
tors.
CHECK ECCS RELAY.
1. Apply 12V direct current between relay ter-
minals
V1andV2.
2. Check continuity between relay terminals
V3andV5.
12V (
V1-V2) applied:
Continuity exists.
No voltage applied:
No continuity
OK
cNG
Replace ECCS relay.
CHECK GROUND CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Loosen and retighten engine ground screws.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM ter-
minals
V6,V13,V39,V48,107,108,116and 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 connectors.
Check ECM pin terminals for damage and
check the connection of ECM harness connec-
tor.
INSPECTION END
SEF072U
SEF073U
SEF074U
SEF090M
SEF075U
.
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR POWER SUPPLYKA
Main Power Supply and Ground Circuit
(Cont'd)
EC-81

Camshaft Position Sensor (CMPS)
COMPONENT DESCRIPTION
The camshaft position sensor is a basic component of the ECCS.
It monitors engine speed and piston position. These input signals
to the ECM are used to control fuel injection, ignition timing and
other functions.
The camshaft position sensor has a rotor plate and a wave-
forming circuit. The rotor plate has 360 slits for a 1É signal and
4 slits for a 180É signal. The wave-forming circuit consists of
Light Emitting Diodes (LED) and photo diodes.
The rotor plate is positioned between the LED and the photo
diode. The LED transmits light to the photo diode. As the rotor
plate turns, the slits cut the light to generate rough-shaped
pulses. These pulses are converted into on-off signals by the
wave-forming circuit and sent to the ECM.
The distributor is not repairable and must be replaced as an
assembly, except distributor cap.
SEF998R
SEF853B
TROUBLE DIAGNOSIS FOR ``CAMSHAFT POSI SEN'' (DTC 11)KA
EC-82

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)
22
30W
WCamshaft position sensor
(REF) (180É signal)Engine is running.
(Warm-up condition)
Idle speedApproximately 0.4V
SEF064U
Engine is running.(Warm-up condition)
Engine speed is 2,000 rpm.Approximately 0.4V
SEF065U
31
40B
BCamshaft position sensor
(POS) (1É signal)Engine is running.
(Warm-up condition)
Idle speedApproximately 2.5V
SEF066U
Engine is running.(Warm-up condition)
Engine speed is 2,000 rpm.Approximately 2.5V
SEF067U
ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble Code
No.Malfunction is detected when ....Check Items
(Possible Cause)
TROUBLE DIAGNOSIS FOR ``CAMSHAFT POSI SEN'' (DTC 11)KA
Camshaft Position Sensor (CMPS) (Cont'd)
EC-83

11lEither 1É or 180É signal is not sent to ECM for the first
few seconds during engine cranking.
.......................................................................................lHarness or connectors
(The camshaft position sensor circuit is open or
shorted.)
lCamshaft position sensorlStarter motor (Refer to EL section.)lStarting system circuit (Refer to EL section.)lDead (Weak) battery
lEither 1É or 180É signal is not sent to ECM during
engine running.
.......................................................................................
lEither 1É or 180É signal is not in the normal pattern
during engine running.
DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE
Before performing the following procedure, confirm that
battery voltage is more than 10V.
1) Turn ignition switch ``ON'' and select ``DATA MONI-
TOR'' mode with CONSULT.
2) Start engine and run it for at least 2 seconds at idle
speed.
(If engine does not run, turn ignition switch to ``START''
for at least 2 seconds.)
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Start engine and run it for at least 2 seconds at idle
speed.
(If engine does not run, turn ignition switch to ``START''
for 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.
SEF051U
TROUBLE DIAGNOSIS FOR ``CAMSHAFT POSI SEN'' (DTC 11)KA
Camshaft Position Sensor (CMPS) (Cont'd)
EC-84

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK STARTING SYSTEM.
Does the engine turn over?
(Does the starter motor operate?)
Yes
cNo
Check starting system.
(Refer to EL section.)
CHECK SHIELD CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Loosen and retighten engine ground
screws.
3. Remove joint connector
M31orF53.
4. Check the following.
lContinuity between joint connector
terminal
V1and ground
lJoint connector
(Refer to ``HARNESS LAYOUT'' in EL
section.)
Continuity should exist.
If OK, check harness for short to
ground and short to power. Then
reconnect joint connector.
OK
cNG
Repair open circuit, short
to ground or short to
power in harness or con-
nectors.
CHECK POWER SUPPLY.
1. Disconnect camshaft position sensor
harness connector.
2. Turn ignition switch ``ON''.
3. Check voltage between terminal
V5
and ground with CONSULT or tester.
Voltage: Battery voltage
OK
cNG
Check the following.
lHarness connectors
M5,E101
lHarness connectors
F54,M48(RHD mod-
els)
lHarness for open or
short between camshaft
position sensor and
ECM
lHarness for open or
short between camshaft
position sensor and
ECCS relay
If NG, repair harness or
connectors.
CHECK GROUND CIRCUIT.
1. Disconnect camshaft position sensor
harness connector.
2. Check harness continuity between ter-
minal
V6and engine ground.
Continuity should exist.
If OK, check harness for short.
OK
cNG
Repair open circuit, short
to ground or short to
power in harness or con-
nectors.
VA
SEF076U
SEF128S
SEF129S
SEF131S
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``CAMSHAFT POSI SEN'' (DTC 11)KA
Camshaft Position Sensor (CMPS) (Cont'd)
EC-87

VA
CHECK INPUT SIGNAL CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Disconnect ECM harness connector.
3. Check harness continuity between ter-
minal
V4and ECM terminalsV31,V40
(1É signal), terminalV3and ECM ter-
minals
V22,V30(180É signal).
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
(Camshaft position sensor).
Refer to ``COMPONENT INSPECTION''
below.
OK
cNG
Replace camshaft position
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
COMPONENT INSPECTION
Camshaft position sensor
1. Start engine.
2. Check voltage between terminals
V3,V4and ground with
DC range.
Condition Terminals Voltage
Engine running at idle
V3and ground Approximately 0.4V*
V4and ground Approximately 2.5V*
*: Average voltage for pulse signal (Actual pulse signal can be confirmed by
oscilloscope.)
If NG, replace distributor assembly with camshaft position
sensor.
3. Visually check signal plate for damage or dust.
SEF077U
SEF750R
AEC148A
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``CAMSHAFT POSI SEN'' (DTC 11)KA
Camshaft Position Sensor (CMPS) (Cont'd)
EC-88

Mass Air Flow Sensor (MAFS)
COMPONENT DESCRIPTION
The mass air flow sensor is placed in the stream of intake air. It
measures the intake flow rate by measuring a part of the entire
intake flow. It consists of a hot wire that is supplied with electric
current from the ECM. The temperature of the hot wire is con-
trolled by the ECM a certain amount. The heat generated by the
hot wire is reduced as the intake air flows around it. The more
air, the greater the heat loss.
Therefore, the ECM must supply more electric current to the hot
wire as air flow increases. This maintains the temperature of the
hot wire. The ECM detects the air flow by means of this current
change.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
MAS AIR/FL SE
lEngine: After warming uplAir conditioner switch: ``OFF''lShift lever: Neutral positionlNo-loadIdle 1.3 - 1.7V
2,500 rpm 1.7 - 2.1V
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)
16 B Mass air flow sensorEngine is running.
(Warm-up condition)
Idle speed1.3 - 1.7V
Engine is running.
(Warm-up condition)
Engine speed is 2,500 rpm.1.7 - 2.1V
17 WMass air flow sensor
groundEngine is running.
(Warm-up condition)
Idle speed0.005 - 0.02V
ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble
Code No.Malfunction is detected when ...Check Items
(Possible Cause)
12
lAn excessively high or low voltage from the sensor is
sent to ECM.*lHarness or connectors
(The sensor circuit is open or shorted.)
lMass air flow sensor
*: When this malfunction is detected, the ECM enters fail-safe mode.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,400 rpm due to the fuel cut.
SEF150U
TROUBLE DIAGNOSIS FOR ``MASS AIR FLOW SEN'' (DTC 12)KA
EC-89

DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE
1) Turn ignition switch ``ON'', and wait at least 6 seconds.
2) Select ``DATA MONITOR'' mode with CONSULT.
3) Start engine and wait at least 3 seconds.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Turn ignition switch ``ON'', and wait at least 6 seconds.
2) Start engine and wait at least 3 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.
SEF078U
TROUBLE DIAGNOSIS FOR ``MASS AIR FLOW SEN'' (DTC 12)KA
Mass Air Flow Sensor (MAFS) (Cont'd)
EC-90