1987 TOYOTA CELICA Service Repair Manual

EFI SYSTEM
- Diagnosis System
FI-31
DIAGNOSTIC CODES (MA) (Cont’d) __
:odc
No. Number of
Check engine
blinks Diagnosis System See
page
FL50 Trouble area
l Vehicle speed sensor
circuit
l Vehicle speed sensor
. ECU ’
I
l Ignition switch circuit
l Ignition switch
l ECU
l Knock sensor circuit
l Knock sensor
l ECU
. ECU
l A/C switch circuit
l A/C switch ‘“q
l A/C am&fire
l Neutral start switch
circuit ’
l Neutral start switch
0 Throttle position sensor
circuit
l Throttle position sensor
l ECU Vehicle Speed
Sensor Signal
Starter Signal No “SPD” signal for 5
seconds when engine speed
is between 2,500 rpm and
4,500 rpm and coolant temp.
is below 80°C (176’F) except
when racing the engine.
No “STA” signal to ECU until
engine speed reaches 800
rpm with vehicle not moving.
Knock Sensor
Signal Open or short circuit in knock
sensor signal. 42
FI161
FHBl
Fl181
FIlei
52
Knock control in ECU faulty. Knock Control
signal in ECU
No “IDL” signal, “NSW”
signal or “A/C” signal to
ECU, with check terminals
El and T shorted. Switch Signal
‘1 WI TWC vehicles only
‘2 7M-GTE only
“3 Abnormalities in the air flow meter may also be detected.
DIAGNOSTIC CODES (MS)
Number of
Check engine
System
blinks
m Normal
fl1604
nn ECU (B) Diagnosis
This appears when none of
the other codes are identified.
Momentary interruption in
power supply to ECU. Trouble area See
page
l Ignition switch circuit
l Ignition switch
l Main relay circuit
l Main relay
l ECU FI-62
l Distributor circuit
0 Distributor
l Starter signal circuit
. ECU IG-3
l Distributor circuit
l Distributor
. ECU IG-3
l Igniter and ignition coil 11
FI1605
n nn RPM Signal No “NE” or “G” signal to
ECU within 2 seconds after
engine has been cranked.
FHBOB
nnnn, RPM Signal No “NE” signal to ECU when
engine speed is above
Fl1807 1,000 rpm. 12
-
13
-
14
-LJUlJUL 1 Ignition Signal 1 * No. “IGF” signal to ECU
6 - 8 times in succession. circuit
0 Igniter and ignition coil
. ECU
.t Fl-70

FI-32 EFI SYSTEM - Diagnosis System
1 ode -
: Number of See
Check engine System Diagnosis Trouble area
paw
blinks
0 Water temp. sensor
. .
clrcult m n FI-68
0 Water temp. sensor
0 ECU _
FllBlO 0 Intake air temp. sensor
r
JUMJJJL Intake Air Temp. Open or short circuit in intake circuit
FI-67
Sensor Signal air temp. sensor signal. 0 intake air temp. sensor
. ECU
fll611
Open circuit in VC signal or
0 Air flow meter circuit
JJJJ n f
‘. ‘( <;
closed.
F11612 .
i Air flow meter circuit
DIAGNOSTIC CODES (MS) (Cont’d)
4-65
32
Fl1613 I I
I 0 Throttle position sensor
Open or short circuit in circuit
41 throttle position sensor signal.
! 0 Throttle position sensor
. ECU
Fl1614
No “SPD” signal for 5
seconds when engine speed
0 Vehicle speed sensor
42 nnnruvl
is below 80°C (176°F) except
when racing the engine.
fl16151
I
No “STA” sianal to ECU until 0 Ignition switch circuit
43
i m Starter Signal /~~n~i,‘,pee~;~ct-;~~~ng : ;;;on switch FI-6!
FM
FM
? -. Fl1616 .^
0 Knock sensor circuit
52
.I JjJJMJjn Eyn$ Sensor ~~n~op:~~ circuit in knock : :gk sensor
53
I F11616
w6,9 Kn$c~i~“,“,‘;“’ Knock control in ECU faulty. l ECU
0 A/C compressor relay
A/C Com-
Open or short circuit in circuit
pressor
Relay Signal A/C compressor relay signal. a A/C compressor relay
. ECU
f12611
0 A/C switch circuit Z
51
No “IDL” signal, “NSW” 0 A/C switch
0 A/C amplifire l Neutral start switch
circuit
0 Neutral start switch
0 Throttle position sensor
circuit
I F11617
0 Throttle position Sensor
. ECU

EFI SYSTEM
- Diagnosis System
FI-33
INSPECTION OF DIAGNOSIS .ClRCUlT
._
Fuse IGN
“CHECK ENGINE”
Fl291
1.
I Dose “CHECK ENGINE” warning light come
on when ignition switch is at ON?
l-l YES System Normal
Does “CHECK ENGINE” warning light come Check wiring between
on when ECU terminal W is grounded to the
YES ECU terminal El and body OK Try another
body? - ground. __c ECU
+NO
Check bulb, fuse and wiring between ECU and
ignition switch. + SAD
Repair or replace
Does “CHECK ENGINE” warning light go off
when the engine is started? YES
. System Normal
NO
Check wiring between ECU and
“CHECK ENGINE” warning light.
1 OK
Is there diagnostic code output when check
connector terminals T(MA) or TEl (MS) and
El are short circuited? t
Check wiring between ECU terminal T and check
NO connector terminal T(MA) or TEl (MS), and ECU
* terminal El and check connector terminal El.
I I
I I
YES
Does “CHECK ENGINE” warning light go out NO
after repair according to malfunction code? ) Further repair required.
&
System OK Cancel out diagnostic code.

-34 EFI SYSTEM - Troubleshooting with Volt/dhmmeter (MA)
. .
TROUBLESHOOTING WITH
VOLT/OHMMETER (MA)
OTE: The following troubleshooting pro-
sdures are designed for inspection of each separ-
te system, and therefore the actual procedure
lay vary somewhat. However, troubleshooting
hould be performed refering to the inspection
lethods described in this manual. The following troubleshooting procedures are
based on the supposition that the trouble lies in
either a short or open circuit in a component out-
side the computer or a short circuit within the
computer.
Jefore beginning inspection, it is best to first make
3 simple check of the fuses, fusible links and the
:ondition of the connectors. If engine trouble occurs even though proper
operating voltage is detected in the computer con-
nectar, then it can be assumed that the ECU is
faulty and should be replaced.
LOCATION OF FUSES AND FUSIBLE LINKS
No.
r 1 Relay Block (RHD)
I
61 I
No. 1 Relay Block (LHD)
Fuse IGN’ Fusible Link
ALT
(7M-GE) 1.259
(7M-GTE) 1 OCjA Fuse IdN 7.5A
EFI Main Relay
No. 2
Relay Block
Fusible Link
AM2 30A Fuse EFI 15A

EFI SYSTEM - Troubleshooting with Volt/Ohmmeter (MA)
FI-35
. .
EFI SYSTEM CHECK PROCEDURE
NOTE:
l Perform all voltage measurements with the connectors
connected.
0 Verify that the battery voltage is 11V or above when
the ignition switch is at “ON”.
Using a voltmeter with high-impedance (IO kQ/V
minimum), measure the voltage at each terminal of the
wiring connectors.
I ) ECU +B
Terminals of ECU (7M-GE)
Symbol ) Terminal Name
E01 POWER GROUND
E02 POWER GROUND
No. 10 INJECTOR (No. 1 and 4)
No. 20 INJECTOR (No. 2 and 6)
STA STARTER SWITCH
No. 30 INJECTOR (No. 3 and 5)
STJ COLD START INJECTOR
El COMPUTER GROUND
NSW NEUTRAL START SWITCH (A/T)
N/C *CLUTCH SWITCH (M/T) 1 Symbol) Terminal Name
T CHECK CONNECTOR
G2 DISTRIBUTOR
VTA THROTTLE POSITION SENSOR
NE DISTRIBUTOR
IDL THROTTLE POSITION SENSOR
IGT IGNITER
IGF IGNITER
THW WATER TEMP. SENSOR Symbol
Terminal Name
L3 ECT COMPUTER
EGR
vsv (EGR)
A/C A/C MAGNET SWITCH
SPD SPEEDOMETER
W WARNING LIGHT
FPR FUEL PUMP RELAY
DFG
DEFOGGER RELAY
THA
AIR TEMP. SENSOR
ECT
ECT COMPUTER
vs AIR FLOW METER
KNK KNOCK SENSOR LP HEADLIGHT RELAY
ISC 1 ISC MOTOR NO. 1 COIL ox OXYGEN SENSOR vc THROTTLE POSITION SENSOR
AIR FLOW METER
ISC 3 ISC MOTOR NO. 3 COIL E2 SENSOR GROUND
ISC 2 ISC MOTOR NO. 2 COIL VSV 1 VSV (AIR CONTROL)
BATT BATTERY
ISC 4 ISC MOTOR NO. 4 COIL Ll ECT COMPUTER +B EFI MAIN RELAY
GQ DISTRIBUTOR VSVP VSV (FPU) IG S/W IGNITION SWITCH
VF CHECK CONNECTOR
Gl DISTRIBUTOR
ECU Terminals 1 L2 ECT COMPUTER
+Bl EFI MAIN RELAY
1 M-REL EFI MAIN RELAY (COIL)
*For cruise control
F10574

FI-36 EFI SYSTEM - Troubleshooting with VoltjOhmmeter (MA)
Terminals of ECU. (7M;GTE)
Symbol Terminal Name Symbol Terminal Name Symbol Terminal Name
EOI POWER GROUND G2 CAM POSITION SENSOR A/C A/C MAGNETIC SWITCH
E02 POWER GROUND VTA
THROTTLE POSITION SENSOR SPD SPEEDOMETER
No, 10 INJECTOR (No. 1 and 4)
NE CAM POSITION SENSOR W
WARNING LIGHT
No. 20 INJECTOR (No. 2 and 6) IDL
THROTTLE POSITION SENSOR FPR FUEL PUMP RELAY
STA STARTER SWITCH IGT IGNITER OIL OIL PRESSURE SWITCH
No. 30 INJECTOR (No. 3 and 5) IGdA IGNITER THA AIR TEMP. SENSOR
STJ COLD START INJECTOR
IGF IGNITER ECT ECT COMPUTER
rEl COMPUTER GROUND KNKl KNOCK SENSOR
t HAC 1 tl
NSW
NEUTRAL START SWITCH (A/T) THW WATER TEMP. S
N/C ‘CLUTCH SWITCH (M/T) KNK2 KNOCK SENSOR 1 vc ) THROTTLE
AIR
FLOW I
LTITUDE COMPENSATION
, .xNSOR
ENSOR 1 FC 1 CIRCUITOPENING RELAY I
IGdB IGNITER ox OXYGEN SENSOR KS AIR FLOW METER
ISC 1 ISC MOTOR NO. 1 COIL E2 SENSOR GROUND BATT BATTERY
r
ISC 3 ISC MOTOR NO. 3 COIL
vsv VSV (FPU) +B EFI MAIN RELAY
ISC 2 ISC MOTOR NO. 2 COIL Ll ECT COMPUTER IG S/W IGNITION SWITCH
ISC 4 ISC MOTOR NO. 4 COIL HT OXYGEN SENSOR +Bl EFI MAIN RELAY
GO CAM POSITION SENSOR L2 ECT COMPUTER TIL
TURBO INDICATOR
VF CHECK CONNECTOR M-REL
EFI MAIN RELAY (COIL) DFG DEFOGGER RELAY
Gl CAM POSITION SENSOR L3 ECT COMPUTER LP HEADLIGHT RELAY
T CHECK CONNECTOR
EGR VSV (EGR)
ECU Terminals
E2 Ll L2 L3 A/C W OIL ECT FC KS +B +Bl
+
F10574 Fll 99:
*For cruise control

EFI SYSTEM - Troubleshooting with’ Volt/Ohmmeter (MA) FI-37
Voltage at EClJ Wiring .Connectors (TIM-GE)
IO. Terminals
Condition STD Voltage
See page
BATT - El
10 - 14 FI-39
IG S/W - El
1 FI-40
M-REL - El
Ignition S/W ON 10 - 14
+B (+Bl) - El FI-41
IDL - E2 Throttle valve open 10 - 14 FI-42
vc - E2 -
4-6
2 Ignition S/W ON -
Throttle valve fully ‘closed 0.1
- 1.0 FI-43
VTA - E2
Throttle valve fully open 4-5
VC - E2 4-6
Ignition S/W ON
Measuring plate fully closed 4-5
3 Measuring plate fully open 0.02 - 0.08 FI-44
VS - E2
Idling 2-4
3,000 rpm 0.3 - 1.0
No. 10 EOI
5 No. 20 - Ignition S/W ON 9 - 14 FI-47
No. 30 E02
6 THA - E2 Ignition S/W ON Intake air temperature 20°C (68°F) 1 -3 FI-48
7 THW - E2 Ignition S/W ON Coolant temperature 80°C II 76’F) 0.1 - 1 .O
FI-49
8 STA - El Cranking
6 - 14 FI-50
9 IGF, IGT - El Idling
0.7 - 1.0 FI-5 1
11 ISCI
I&4 - El Ignition S/W ON 9-14 Fl-53
12 W - El No trouble (“CHECK ENGINE” warning light off) and
engine running 8 - 14 FI-54
13 A/C - El Air conditioning ON IO - 14 FI-55
ECU Terminals
‘~,~] E2 4
/UC W:G up +S :,:I
N:y Is’ Is’ GO Gl G2 NE IGT IGF THW OX “s, “;“riL EGR SPD FPR THA VS VC BATT IG
F1057

EFI SYSTEM - Troubleshooting with Volt/Ohmmeter (MA)
. .
Voltage at ECU Wiring Connectors (7M-GTE)
No. Terminals
Condition STD Voltage Sea page
BATT - El 10 - 14
FI-39
IG S/W - El
1
FI-40
M-REL - El Ignition S/W ON 10 - 14
+B (+Bl) - El
FI-41
*
IDL - E2 Throttle valve open 10 - 14 FI-42
VC - E2 4-6.
2 . Ignition S/W ON
Throttle valve fully closed 0.1 - 1.0 FI-43
VTA - E2
Throttle valve fully open 4-5
i
KS - Body Ignition S/W ON 4-6
FI-45
gnMid
4 Cranking or running 2-4
vc - Body
Ignition S/W ON 4-6
groulld Fl-46.
No. 10 EOl
5 No. 20 - Ignition S;W CN 9 - 14 Fl-47
No. 30 E02
6 THA - E2 Ignition S/W ON Intake air temperature 20°C (68°F) 1 -3 FI-48
7 THW - E2 Ignition S/W ON Coolant temperature 80°C (176°F) 0.1 - 1 .O FI-49
8 STA - El Cranking 6-14 FI-50
9 IGF, IGT - El Idling 0.7 - 1.0 FI-5 1
10 IGdA, IGdB - El Idling 1-3 FI-52
11 I Cl
7 9 - 14 FI-53
ISC4 - El Ignition S/W ON
12 W - El No trouble (“CHECK ENGINE” warning light off) and
engine running 8 - 14 FI-54
13 A/C - El
14 HAC - E2 Air conditioning ON 10 - 14
FI-55
540 mmHg (21.26 in.Hg. 72.0 kPa) Approx. 2.8
Ignition S/W ON FI-56
750 mmHg (29.53 in.Hg, 100.0 kPa) Approx. 3.6
ECU Terminals
I U 1 I -
I
1
‘yc ‘;c GQ Gl G2 NE IGT IGF ~Hln, OX “;’ HT r;,
EGR SPD FPR THA HAC VC ‘JAn& 0 DF
‘;’ ‘sd: VF T VTA IDL
WA ““1” K;K E2 Ll L2 L3 NC W OIL ECT FC KS +B +Bl m
TIL LP