NISSAN 300ZX 1984 Z31 Engine Fuel And Emission Control System Service Manual

SELF-DIAGNOSIS
Decoding Chart (Cont'd)
AK condnioner svstem I 16 malfunctioning
Code No 31 ~~
A ~ Green , ?/=%$== =- ~~ 0 Red
000 0
SEF665B
Starter rlgnal IS malfunctioning
Code
No 32
I2 SEF666B
CodeNo 34
Detonation sensor Circuit IS malfunc
tiontng IVG30ET enginel
See page
EF&EC52
SEF667B I ~
See
page EF & EC-53
I
Fuel temperature sensor circuit IS malfunnmnlng
Code No 41
=-a
Red Green
0
II SEF668B
EF & EC-41

SELF-DIAGNOSIS
Decoding Chart (Cont'd)
Code No. 44 ~
m-w -
Red Green
.,
0'
SEF669B
EF 81 EC-42

ELECTRONIC CONTROL SYSTEM INSPECTION
Check harness between crank angle sensor and
control unit
PREPARATION
Before checking the following items, ensure that each connector IS securely connected
N G ~ harness
Repair or replace harness and high tension cable
or dust
Visually check crank angle sensor for damage 1 “--+I Replace crank angle sensor
OK
Replace E C C S control unit 1
EF & EC-43

ELECTRONIC CONTROL SYSTEM INSPECTION
VG -
@Air flow meter (Code No 12)
Check harness for continuity
Disconnect 16pin connector and connect terminal
@to ground with
a jumper wire
NG -
Turn ignition switch ”ON” and measure voltage
between terminals @and
@I
Replace air flow meter
1 6tO 1V
SEF671B
O “I
Remove air flow meter Apply battery voltage to
terminals
D and E
Then measure voltage between terminals Band D
SEF672B
I
OK
7
IN
Repair harness
OK
@
EF 81 EC-44

ELECTRONIC CONTROL SYSTEM INSPECTION
+I Replace control unit
t +I Replace air flow meter
Blow air through air flor meter and measure voltage
between terminals
B and D
Blo
I
I SEF6730
Air flow meter self cleaning circuit
Check for continuity between terminal @of
20-pin connector and ground
I
n
Contwny should extR
SEF6748
___~
Check air flow meter for continuity between terminal
C and F
Check harness for continuitv
Replace air flow meter
I Continuity should exis
SEF6750
EF & EC-45

ELECTRONIC CONTROL SYSTEM INSPECTION
@ Cylinder head temperature sensor (Code No 13)
Disconnect 16-pin connector and measure the
resistance between terminals @and
@$
Dip the sensor into water maintained at a temper-
ature
of 20°C (68°F). 80°C (176°F). etc, and read
its resistance
2
I lo; - - c4
- ;2
c 66
g2
m : io3 u
z4 *
102
-30 0 40 80 120 (-221 I321 (1041 11781 (2481 -20 20 60 100 130 (-41 (681 (1401 (2121 (2661
Temperature "C (OF) -
SEF677B
(OK I N G.
Replace cylinder head temperature sensor
EF & EC-46

ELECTRONIC CONTROL SYSTEM INSPECTION
:@ Vehicle speed sensor (Code No. 14)
Disconnect speedometer cable from transmission
I
SEF678B
I
Disconnect 16-pin connector from E C C S control
unit and check continuity between terminal
@
and ground while slowly turning speedometer cable
ONIOFF puk should be detected n
(Refer to “METER AND GAUGES in
Replace E C C S control unit
EF & EC-4‘7

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