1987 TOYOTA CELICA Service Repair Manual

EFI SYSTEM - Troubleshooting with Volt/Ohmmeter (MS)
FI-63
No. 1 Terminals 1 Trouble 1
Condition S-m Vnlttlnq --- ‘-‘-P-~
IDL
- E2 Throttle valve open
10 - 14 v
vcc - E2
2
No voltage Ignition 4-6V
switch ON
VTA - E2 Throttle valve fully closed 0.1 - l.OV
Throttle valve fully open
4-!iv
ECU .s
r
Fl136
I . IDL - E2
ECU
I ECU
I Y ,
F12767
0 There is no voltage between ECU terminals IDL and E2.
(IO S/W ON) (Throttle valve open)
I
1
0 Check that there is voltage between ECU terminal B (Bl) and
body ground.
(IO S/W ON)
NO
OK
, 1
I I Check wiring between ECU terminal El and body
I
1 ground.
OK
Try another ECU. 1
BAD
I Repair or replace.
I i
t
Refer to No. 1. BAD
(See page FI-62) p Replace or repair.
t
OK
, t
I@ Check throttle position sensor, ]
BAD
BAD
OK
*
Replace or repair Check wiring between ECU and
throttle position sensor. throttle position sensor.
1
OK
Try another ECU.
‘!
t

FI-64 EFI SYSTEM - Troubleshooting with Volt/Ohmmeter (MS)
Fl162
. VCC - E2 .
0
There is no voltage between ECU terminals VCC and E2.
(IO S/W ON)
1
I
Check that there is voltage between ECU terminal B (Bl) and
body ground. II0 S/W ON1
OK
7
0 Check throttle position sensor. Refer to No. 1.
(See page FL102)
(See page FL62)
k
I OK
,
1 Repair or replace.‘ / Check wiring between ECU and throttle position sensor.
OK
t I , 1 BAD ,
1 Rwe;ix3;.or replace ]
Try another ECU.
l VTA - E2
I- I
0 There is no specified voltage at ECU terminals VTA and E2.
(IG S/W ON)
I
0 Check that there is voltage between ECU terminal VCC and E2.
(IO S/W ON)
I 1
I OK
I
[@ Check thrc1 BAD 4 Repair or replace. 1
I
1 OK I ‘1 4 Check wiring between ECU and
throttle position sensor.
I
1 OK BAD
- Repair or replace.
1 Try another ECU.
1
I

EFJ SYSTEM - Troubleshooting with Volt/Ohmmeter (MS) FI-65
-_
No.
Tprminals Trouble Condition ._
STD Voltage
vcc
- E2
4-6V
Ignition
vs
- E2
SIW ON Measuring plate fully closed
4-6V
3 vs - E2 No voltage Measuring plate fully open
0.02 - 0.08 V
vs
- E2 Idling
2-4V
vs
- E2 3,000 rpm
0.3 - 1.0 v
0 ^,
-’ E2
r; wt.
I ’
I Air Flow Meter Air Flow Meter
# #
I- I-
= =
ECU
Air Flow Meter
I
FIl28:
I
I
I
ECU
El
Fl126!
0 There is no voltage between ECU terminals VCC or VS and E2.
(IG S/W ON)
1
0 Check that there is voltage between ECU terminal B @I) and
body ground. (IG S/W ON)
c
OK
NO
7
Refer to No. 1.
(See page FI-62)
7
Check wiring between ECU terminal El and body ground.
OK BAD
0 Check air flow meter.
(See page FI-96) Repair or replace.
,+, ,I, Check wiring between ECU and air
Try another ECU.

FI-66 EFI SYSTEM - Troubleshooting with VoltjOhrnmeter (MS)
-.
Ua. I
Terminals 1 Trouble 1 Condition
I STD Voltage
No. 10
EOI
4 No. 20 - ignition switch ON g-14v
No. 30 E02 No voltage
Battery i
T
ECU
IG S/W
‘No. IO ‘No. 20
‘No. 30
IEOI
I E02
c
+? &
=
FU.9
mb Fl291
0 There is no voltage between ECU terminal No. IO, No. 20
and/or No. 30 and EOl or E02. (IG S/W ON)
‘
J
0 Check that there is specified voltage between resistor
terminal +B and body ground. STD voltage: 9 - 14 V
Check wiring between
resistor and battery. BAD
-t Repair or replace.
I
Check that there is specified voltage between resistor terminal
@ (No. 10, No. 20 or No. 30) and body ground.
STD voltage: 9 - 14 V
I
e,+i Check resistance of magnetrc co11 rn
I
Check wiring between ECU and
iniector. I I Replace injector,

No. Terminals Trouble Condition STD Voltage
I I I I I
5 THA - E2
I No voltage ON
I Ignition switch Intake air temperature 20°C
(66°F) 1 -3v
0 ”
0 6
L -
,’ E2 (B?)
(5E2
( THA
Air Temp. Sensor
(Air Flow Meter) o El
ECU
fl275'
Air Flow Meter ’
0 There is no voltage between ECU terminals THA and E2.
(IG S/W ON)
I
0 Check that there is voltage between ECU terminal B (Bl 1 and
body ground. (IG S/W ON)
OK NO
Refer to No. 1.
(See page FI-62)
1
Check wiring between ECU terminal El and body ground.
OK
0 Check air temp. sensor.
(See page FI-96) Repair or replace.
c
BAD
OK
Replace air frow Check wiring between ECU and air
meter. temp. sensor.
OK BAD
Try another ECU.
I 1 Repair or replace. 1

EFI SYSTEM
- Troubleshooting with Voltkhmmeter (MS)
-.
No. 1
Terminals
I Trouble
I Condition ._
I STD Voltage
6 THW - E2 .No voltage Ignition switch Coolant temperature 80°C
ON (, 760F) 0.1 - 1.0 v
Water Temp. Sensor
. ECU
5 031)
THW
E2
:1
ECU I terminals THW and E2.
I
0 There is no voltage between ECU
(IG S/W ON)
I-
:.
0 Check that there is voltage between ECU terminal B (61) and
body ground. (IG S/W ON) -
1
OK NO
I
I 8 1
I
Refer to No. 1.
(See page FL62)
I
I I . -
I
Check wiring between ECU terminal El and body ground.
I BAD
Check water temp. sensor.
Repair or replace.
BAD
Replace water
temp. sensor. OK
Check wiring between ECU and water
I temp. sensor.
OK BAD
Try another ECU. 1 Repair or replace. 1

EFI SYSTEM - Troubleshooting with Volt/Ohmmeter (MS)
FI-69
No. 1 Terminals 1 Trouble 1 Coridition
1 .STD Voltage
7 1 STA - El No voltage Cranking
6-14V
Fusible Link
AM1 40A
ALT 1OOA
r
Battery
1 Ignition Switch
l~ol Fuse
AMIj “V
lsT’ST 7.5A Neutral Start To Circu
,Opening
Relay
,
(M/T)
,
I I
Fusible
Link
% MAIN
Starter
Relay ECU
STA
El
ECU
Ft275!
0 There is no voltage between ECU terminals STA and El.
(IO S/W START)
I
Check starter OK
operation.
BAD Check &ring between ECU terminal STA
and ignition switch terminal STI.
OK BAD
Repair or replace.
t
0 Check wiring between ECU terminal El and body
ground.
v OK
Try another ECU. BAD
Repair or replace.
Check fusible links, battery, wiring,
ignition switch and neutral start BAD
c Repair or replace.
switch.
I
OK
0 Check that there is voltage at STA (50) terminal of starter.
OG S/W START) STD voltage: 6 - 14 V
OK
NO
c
Check starter. Check wiring between ignition switch
terminal ST1 and starter terminal STA (50).

. .
No. Terminals Trouble Condition
STD Voltage
8 IGT, IGF - El No voltage Idling -- 0.7-l.OV
Ignition SW
Fusible
a AM2
Link 30A EFI SYSTEM - Troubleshooting with Volt/Ohmmeter (MS)
F12771
Y , F1277
ECU 8
&z
F12755
0 There is no voltage between ECU terminals IGT and El.
(Idling)
0 Check that there is voltage between ECU terminal IGT and
body ground. (Idling)
I
NO OK
0 Check wiring between ECU BAD Repair or
terminal El .and body ground. replace.
I OK
1 Try another ECU.
I
Check fusible link and ignition
switch. BAD
BAD
Repair or replace.
I I I
I OK I T
1 I I
Check wiring between ECU and
battery.
I BAD
c Repair or replace.
BAD
Repair or replace.
I
I 1 I