1998 NISSAN PATROL battery

Charge Air Cooler Fan Control
SYSTEM DESCRIPTION
Crankshaft position sensor (TDC)cEngine speed
ECM
cCharge air cooler fan relayCharge air temperature sensorcCharge air temperature
Ignition switch
cStart signal
The ECM controls the charge air cooler fan operation corresponding to the engine speed, the charge air tem-
perature and the start signal. The control system has 2-step control [ON/OFF]. The ECM does not directly drive
the charge air cooler fan. It controls the ON/OFF charge air cooler fan relay, which in turn controls the charge
air cooler fan.
When the charge air temperature is above 67ÉC (153ÉF) and engine speed is more than 1,600 rpm, the charge
air cooler fan operates.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
I/C FAN RLY+When charge air cooler fan is stopped. OFF
+When charge air cooler fan operates. ON
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)
8 G/ORCharge air cooler fan
relayEngine is running.
Charge air cooler fan is not operating.BATTERY VOLTAGE
(11 - 14V)
Engine is running.
Charge air cooler fan is operating.0-1V
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EC-178

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK OVERALL FUNCTION.
1. Turn ignition switch ``OFF''.
2. Disconnect charge air temperature sen-
sor harness connector.
3. Connect 150Wresistor to charge air
temperature sensor harness connector.
4. Start engine and keep engine speed at
2,000 rpm.
5. Make sure that charge air cooler fan
operates.
NG
cOK
INSPECTION END
CHECK POWER SUPPLY.
1. Stop engine.
2. Disconnect charge air cooler fan relay.
3. Turn ignition switch ``ON''.
4. Check voltage between terminals
V2,
V5and ground with CONSULT or
tester.
Voltage: Battery voltage
OK
cNG
Check the following.
+Harness connectors
M21,E127
+10A fuse
+15A fuse
+Fuse block
M2
+Harness for open or
short between charge air
cooler fan relay and
fuses
If NG, repair harness or
connectors.
CHECK GROUND CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Disconnect charge air cooler fan motor
harness connector.
3. Check harness continuity between relay
terminal
V3and motor terminalV1,
motor terminal
V2and engine ground.
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
M50,F5
+Harness for open or
short between charge air
cooler fan relay and
charge air cooler fan
motor
+Harness for open or
short between charge air
cooler fan motor and
engine ground
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
jA
SEF710V
SEF798V
SEF712V
SEF799V
SEF711V
.
.
.
.
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
Charge Air Cooler Fan Control (Cont'd)
EC-180

COMPONENT INSPECTION
Charge air cooler fan relay
Check continuity between terminalsV3andV5.
Conditions Continuity
12V direct current supply between
terminals
V1andV2Ye s
No current supply No
If NG, replace relay.
Charge air cooler fan motor
1. Disconnect charge air cooler fan motor harness connector.
2. Supply charge air cooler fan motor terminals with battery volt-
age and check operation.
Charge air cooler fan motor should operate.
If NG, replace charge air cooler fan motor.
SEF511P
SEF802V
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
Charge Air Cooler Fan Control (Cont'd)
EC-182

Heat Up Switch
The heat up switch is located on the lower side of the instrument
panel. This switch is used to speed up the heater's operation when
the engine is cold.
When the ECM received the heat up switch ``ON'' signal, the ECM
increases the engine idle speed to 1,100 - 1,200 rpm to warm up
engine quickly.
This system works when all conditions listed below are met.
Heat up switch ON
Engine coolant temperature Below 70ÉC (158ÉF)
Shift lever ``P'' or ``N''
Accelerator pedal Fully released
Vehicle speed Below 4 km/h (2 MPH)
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
WARM UP SW+Ignition switch: ONHeat up switch: ON ON
Heat up switch: OFF OFF
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)
59 BR/W Heat up switchIgnition switch ``ON''
Heat up switch is ``OFF''.0V
Ignition switch ``ON''
Heat up switch is ``ON''.BATTERY VOLTAGE
(11 - 14V)
SEF803V
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EC-183

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK OVERALL FUNCTION.
1. Turn ignition switch ``ON''.
2. Check ``WARM UP SW'' signal
in ``DATA MONITOR'' mode with
CONSULT.
Heat up switch is ``ON'': ON
Heat up switch is ``OFF'': OFF
--------------------------------------------------------------------------------------------------------------------------------------OR--------------------------------------------------------------------------------------------------------------------------------------
2. Check voltage between ECM
terminal
V59and ground under
the following condition.
Voltage:
Heat up switch is ``ON''
Battery voltage
Heat up switch is ``OFF''
Approximately 0V
NG
cOK
INSPECTION END
CHECK POWER SUPPLY.
1. Turn heat up switch ``OFF''.
2. Turn ignition switch ``OFF''.
3. Disconnect heat up switch harness con-
nector.
4. Turn ignition switch ``ON''.
5. Check voltage between terminal
V6
and ground with CONSULT or tester.
Voltage: Battery voltage
OK
cNG
Check the following.
+Fuse block
M3
+10A fuse
+Harness for open or
short between heat up
switch and fuse
If NG, repair harness or
connectors.
CHECK INPUT SIGNAL CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM
terminal
V59and terminalV5.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
+Harness connectors
M51,F6
+Harness for open or
short between heat up
switch and ECM
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
jA
SEF804V
SEF805V
SEF806V
SEF807V
.
.
.
.
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
Heat Up Switch (Cont'd)
EC-185