code 41 NISSAN 300ZX 1984 Z31 Engine Fuel And Emission Control System User Guide

ELECTRONIC CONTROL SYSTEM INSPECTION
Tester
Ohmmeter
@ ignition signal (Code No 21)
Leads 'Ins ~ Should read I+) I-)
E&
CZ 3 Continuity exists
e@
A
SEF682E
Disconnect 20-pin connector and check continuity
between terminals 0. @and ground
Continuity should exst
SEF681B
OK1 ~~
Check
power transistor
Without harness Connector l
Wlth harness connector
Check harness, and repair as
necessarv
I
Replace E C C S control unit I
9 Replace power transistor I I I
EF & EC-48

ELECTRONIC CONTROL SYSTEM INSPECTION
OK -+
@ Fuel pump (Code No. 22)
Replace E C C S control unit
Turn ignition switch "ON" and listen to the fuel
pump operating sound The sound must be heard for
about
5 seconds
Check Normal
12V direct current
18 applied between ~
Disconnect E C C S 15-pin
connector. and check
voltage between terminal
@ and ground when
ignition switch
is turned to ON
Replace fuel pump
Battery voltage
SEF683B
OK I
Replace fuel pump relay
Check fuel pump for ContinuitY
Contmuny should exis
SEF684B
OK1 ING
Check harness for continuity
OK I ING
I Repair harness
OK
Check fuel pump relay
NO @ - @ I C0"tl""ltY
SEF685B
ING
EF & EC-49

ELECTRONIC CONTROL SYSTEM INSPECTION
@ Throttle valve switch (Code No. 23)
Check harness for continuity
OK 1
Check the throttle valve switch for continuity
between
@ and @
Continuitv should exin
SEF686B
0.K I
Check continuity between @, @$ and ground
(Insulation check)
SEF6888
+
Replace E C C.S control unit
rlG
Adjust idle switch
1) On VG30ET engine only, disconnect
A A C
valve harness connector
2) Hold engine speed as follows by manually
opening the throttle
valve
VG30E engine (Without turbocharger)
VG30ET engine (With turbocharger)
3) Adfust idle switch so that the switch
900+50 rpm
850*50 rpm
turns on at that engine speed
SEF687B
1) If idle switch cannot be adjusted, replace
5) Connect A A C valve harness connector
throttle valve switch
Replace throttle valve switch
EF 81 EC-50

ELECTRONIC CONTROL SYSTEM INSPECTION
Start engine, turn air conditioner switch "ON" and
check compressor operation
@! NeutraVPark switch (Code No. 24)
N G + Check air conditioner system
Check harness for continuity F.1 Repair harness
OK I
NG -
Check neutrallpark swltch
Repair harness
Press I)
Free INeutrall 057 press IOtherrl -57 SEC764
OK I
Replace neutrallpark switch
I"
Replace E C C S control unit
0 Air condttloner (Code No. 31)
Stop engine and disconnect 16-pin connector Turn
ignition switch
"ON" and measure voltage between
terminal
@ and ground
I Battery voltage
SEF690B
OK I
+
Replace E C C S control unit
EF & EC-51

ELECTRONIC CONTROL SYSTEM INSPECTION
@ Start signal (Code No. 32)
Repair or replace NG Check starting system 1
OK
20-pin connector and measure voltage between
terminal and ground
Emery voltage
SE F691 B I OK I
Replace E C C S control unit
@ Detonation sensor (Code No. 34)
1 ) Disconnect detonation sensor harness connector
2)
Start engine and increase engine speed while
checking ignition timing
3) Check if ignition timing retards by 5 degrees when
engine speed increases when engine speed increases
more than 2,000 rpm
I SEF692B
Repair harness
(Refer to
EL section I
Replace E C.C.S control unit
Repair harness N.G OK1
Replace detonation sensor.
EF & EC-52

ELECTRONIC CONTROL SYSTEM INSPECTION
Replace E C C S control unit
Fuel temperature sensor (Code No. 41)
Replace fuel temperature sensor and
Disconnect 20-pin connector and measure the
resistance between terminal
@ and ground
Fuel temperature I Resirlance
Above20'C 168'Fl I Below 2 9 kC
Below 2O:C 168"FI Above 2 1 kC1
-
SEF693B
Repair harness 1
Measure the resistance of the fuel temperature sensol
i c3425 2
1 '"
-
- :2
2 - ? 103
i6
-24 Y
t+2
10'
-30 0 40 80 1M (-221 (321 (1041 (1761 (248) -20 20 60 100 130 1-41 (681 (1401 12121 (2661
Temperarure 'c 1°F) -
EF %I EC-53