ECU TOYOTA TERCEL 1996 Service Owner's Guide

DI98C-01
R03953
A13
1 2 3 4 5 6
7 8 9 10 11 1213
14 15
16 17 18 19 20 21 22 23 24 25 2612 11 12 3 4 5 6 7 8 9 10
A12
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
DI-1 17
1996 TERCEL (RM440U)
TERMINALS OF ECU
Symbols (Terminal No.)Wiring ColorConditionSTD Voltage (V)
IG1 (A12-5) - GND (A13-7)B-Y - W-BIG switch ON10 - 14
SR (A12-20) - R+ (A12-4)G-B - L-BIG switch ON9 - 14
MR (A12-7) - R+ (A12-4)G-R - L-BIG switch ONBelow 1.0
SFRR (A13-5) - GND (A13-7)Y-R - W-BIG switch ON ABS warning light OFF10 - 14
SFRH (A13-6) - GND (A13-7)Y - W-BIG switch ON ABS warning light OFF10 - 14
SFLR (A12-2) - GND (A13-7)R-B - W-BIG switch ON ABS warning light OFF10 - 14
SFLH (A12-1) - GND (A13-7)P - W-BIG switch ON ABS warning light OFF10 - 14
SRRR (A12-15) -
GND (A13-7)L-W - W-BIG switch ON ABS warning light OFF10 - 14
SRRH (A12-14) -
GND (A13-7)R-W - W-BIG switch ON ABS warning light OFF10 - 14
SRLR (A13-11) - GND (A13-7)G-Y - W-BIG switch ON ABS warning light OFF10 - 14
SRLH (A13-12) -
GND (A13-7)Y-B - W-BIG switch ON ABS warning light OFF10 - 14
AST (A12-8) - GND (A13-7)LG - W-BIG switch ON ABS warning light OFF10 - 14
MT (A12-26) - GND (A13-7)LG-B e W-BIG switch ONBelow 1.5
WA (A12 18) GND (A13 7)RL WBIG switch ON ABS warning light ONBelow 2.0WA (A12-18) - GND (A13-7)R-L - W-BIG switch ON ABS warning light OFF10 - 14
STP (A12 12) GND (A13 7)GW WBStop light switch OFFBelow 1.5STP (A12-12) - GND (A13-7)G-W - W-BStop light switch ON8 - 14
Tc (A12-25) - GND (A13-7)P-B - W-BIG switch ON10 - 14
Ts (A12-24) - GND (A13-7)L - W-BIG switch ON10 - 14
FR+ (A12-10) - FR- (A12-9)B - WIG switch ON Slowly turn right front wheelAC generation
FL+ (A12-22) - FL- (A12-23)R - GIG switch ON Slowly turn left front wheelAC generation
RR+ (A13-8) - RR- (A13-9)L - LGIG switch ON Slowly turn right rear wheelAC generation
RL+ (A13-3) - RL- (A13-2)V - PIG switch ON Slowly turn left rear wheelAC generation

DI4LT-02
DI-1 18
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
1996 TERCEL (RM440U)
PROBLEM SYMPTOMS TABLE
If a normal code is displayed during the DTC check but the problem still occurs, check the circuits for each
problem symptom in the order given in the table below and proceed to the relevant page for troubleshooting.
SymptomsSuspected AreaSee page
ABS does not operate
Only when 1 - 4 are all normal and the problem is still occurring, replace the ABS
ECU
6. Check the DTC, reconfirming that the normal code is output
7. IG power source circuit
8. Speed sensor circuit
9. Check the ABS actuator with a checker
If abnormal, check the hydraulic circuit for leakage (See page DI-145).
DI-1 11
DI-132
DI-128
BR-35
ABS does not operate effi-
ciently
Only when 1 - 4 are all normal and the problem is still occurring, replace the ABS
ECU
1. Check the DTC, reconfirming that the normal code is output
2. Speed sensor circuit
3. Stop light switch circuit
4. Check the ABS actuator with a checker
If abnormal, check the hydraulic circuit for leakage (See page DI-145)
DI-1 11
DI-128
DI-136
BR-35
ABS warning light abnormal1. ABS warning light circuit
2. ABS ECUDI-138
-
DTC check cannot be done
Only when 1 and 2 are all normal and the problem is still occurring, replace the
ABS ECU
1. ABS warning light circuit
2. Tc terminal circuit
DI-138
DI-141
Speed sensor signal check
cannot be done1. Ts terminal circuit
2. ABS ECUDI-143
-

DI4LU-03
W00704
ABS
EA2 2
DLC1 F71
F63
5
MAIN FL
BatteryEngine Room R/B
L
4
12
21L
A6
A71
2
A7A6
A6
A7 6
2
A6
A71Motor Relay
EB
7
ABS ECU
G-R
L-B
G-B
W-B
W-B
EA
A5
A5A5
A5
A5 12
4
3
5LG
LG-B ABS ECU L-WR+MR
A12
A12
A12
A12SR
AST
MT 4
20
8
26
ABS
EA2 2
F71
ALT
F63
5
MAIN FL
BatteryEngine Room R/B
4
1 B-Y
B2
LA6
A71
2
A7A6
A6
A7 6
A6
A7Solenoid
RelayMotor Relay ABS Control Relay
7
G-R
L-B
G-B W-B
W-B
W-B
W-B W-B
A5
A5A5
A5
A5 12
4
LG
LG-B
ABS ActuatorR+MR
SR
AST
MT 4
20
26 Fuse
BlockA12
B-Y2
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
DI-1 19
1996 TERCEL (RM440U)
CIRCUIT INSPECTION
DTC 11, 12 ABS Control (Solenoid) Relay Circuit
CIRCUIT DESCRIPTION
This relay supplies power to each ABS solenoid. After the ignition switch is turned ON, if the initial check is
OK, the relay goes on.
DTC No.DTC Detecting ConditionTrouble Area
11
Conditions 1 and 2 continue for 0.2 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage:
Battery positive voltage
2. ABS control (solenoid) relay monitor terminal (AST) volt-
age: 0 V

ABS control (solenoid) relay

Open or short in ABS control (solenoid) relay circuit

ECU
12
Conditions 1 and 2 continue for 0.2 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage: 0 V
2. ABS control (solenoid) relay monitor terminal (AST) volt-
age: Battery positive voltage
ABS control (solenoid) relay

B+ short in ABS control (solenoid) relay circuit

ECU
Fail safe function:
If trouble occurs in the ABS control (solenoid) relay circuit, the ECU cuts off current to the ABS control (sole-
noid) relay and prohibits ABS control.
WIRING DIAGRAM

F00387
LOCK
A7
R04370
ECUECU ECUECUA12 A5A5 A5A5 A7
5
4
38 ABS
Actuator ABS Control
Relay
DI-120
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Check voltage between terminals A7-2 and A7-6 of ABS control relay connector.
PREPARATION:
Disconnect the ABS control relay connector.
CHECK:
Measure the voltage between terminals A7-2 and A7-6 of the
ABS control relay harness side connector.
OK:
Voltage: 10 - 14 V
NG Check and repair harness or connector.
OK
2 Check continuity between terminal A7-5 and A5-4, A5-4 and A5-3, and A5-3
and A12-8.
PREPARATION:
Disconnect the connector from the ABS actuator.
CHECK:
Check the continuity between terminals A7-5 and A5-4, A5-4
and A5-3, and A5-3 and A12-8.
OK:
Continuity
HINT:
There is a resistance of 32 - 34 W between terminals A5-4 and
A5-3.
NG Repair or replace harness or ABS actuator.
OK

F00388
Continuity
Open
(-)
(+)A6
Continuity
Open Continuity A7
A6A7
1 2
3
45 6
1 2 3
5
6 1 2
3 4
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
DI-121
1996 TERCEL (RM440U)
3 Check ABS control relay.
CHECK:
Check the continuity between each terminal of the ABS control
(solenoid) relay.
OK:
Terminals A7-1 and A6 -3Continuity
(Reference value 80 W)
Terminals A7-5 and A7 -6Continuity
Terminals A7-2 and A7-5Open
CHECK:
(a) Apply battery voltage between terminals A7-1 and A6-3.
(b) Check the continuity between each terminal of the ABS
control relay.
OK:
Terminals A7-5 and A7-6Open
Terminals A7-2 and A7-5Continuity
NG Replace ABS control relay.
OK
4 Check for open and short in harness and connector between ABS control relay
and ABS ECU (See page IN-26).
NG Repair or replace harness or connector.
OK
If same code is still output after DTC is deleted, check contact condition of each connection. If
connections are normal, ECU may be defective.

W00704
ABS
EA2 2
DLC1 F71
F63
5
MAIN FL
BatteryEngine Room R/B
L
4
12
21L
A6
A71
2
A7A6
A6
A7 6
2
A6
A71Motor Relay
EB
7
ABS ECU
G-R
L-B
G-B
W-B
W-B
EA
A5
A5A5
A5
A5 12
4
3
5LG
LG-B ABS ECU L-WR+MR
A12
A12
A12
A12SR
AST
MT 4
20
8
26
ABS
EA2 2
F71
ALT
F63
5
MAIN FL
BatteryEngine Room R/B
4
1 B-Y
B2
LA6
A71
2
A7A6
A6
A7 6
A6
A7Solenoid
RelayMotor Relay ABS Control Relay
7
G-R
L-B
G-B W-B
W-B
W-B
W-B W-B
A5
A5A5
A5
A5 12
4
LG
LG-B
ABS ActuatorR+MR
SR
AST
MT 4
20
26 Fuse
BlockA12
B-Y2 DI-122
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
1996 TERCEL (RM440U)
DTC 13, 14 ABS Control (Motor) Relay Circuit
CIRCUIT DESCRIPTION
The ABS control (motor) relay supplies power to the ABS pump motor. While the ABS is activated, the ECU
switches the ABS control (motor) relay on and operates the ABS pump motor.
DTC No.DTC Detecting ConditionTrouble Area
13
Conditions 1 and 2 continue for 0.2 sec. or more:
1. ABS control (motor) relay terminal (MR) voltage:
Battery positive voltage
2. ABS control (motor) relay monitor terminal (MT) voltage:
0 V

ABS control (motor) relay

Open or short in ABS control (motor) relay circuit

ECU
14
Conditions 1 and 2 continued for 4 sec. or more:
1. ABS control (motor) relay terminal (MR) voltage: 0 V
2. ABS control (motor) relay monitor terminal (MT) voltage:
Battery positive voltage
ABS control (motor) relay

B+ short in ABS control (motor) relay circuit

ECU
Fail safe function:
If trouble occurs in the ABS control (motor) relay circuit, the ECU cuts off the current to the ABS control (sole-
noid) relay and prohibits ABS control.
WIRING DIAGRAM
DI4LV-03

F00389
A6
(-)
(+)
1A6
(-)
(+)
1A6
(-)
(+)
1
LOCK
A6
(-)
(+)
1
R04371
A6
A5
A12 ABS Control
ABS
ECUA5
A5A5
Actuator Relay
2
2
5
26
A6
A5
A12 ABS Control
ABS
ECUA5
A5A5
Actuator Relay
2
2
5
26
A6
A5
A12 ABS Control
ABS
ECUA5
A5A5
Actuator Relay
2
2
5
26
A6
A5
A12 ABS Control
ABS
ECUA5
A5A5
Actuator Relay
2
2
5
26
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
DI-123
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Check voltage between terminals A6-1 of ABS control relay and body ground
PREPARATION:
Disconnect the ABS control relay connector.
CHECK:
Measure the voltage between terminals A6-1 of the ABS con-
trol relay harness side connector and body ground.
OK:
Voltage: 10 - 14 V
NG Check and repair harness or connector.
OK
2 Check continuity between terminals A6-2 and A5-2, A5-2 and A5-5, and A5-5
and A12-26.
PREPARATION:
Disconnect the connector from the ABS actuator.
CHECK:
Check the continuity between terminals A6-2 and A5-2, A5-2
and A5-5, and A5-5 and A12-26.
OK:
Continuity
HINT:
There is a resistance of 32 - 34 W between terminals A5-2 and
A5-5.
NG Repair or replace harness or ABS actuator.
OK

F00411
Open
ContinuityA6
1(+) (-)
A7
Continuity
A6
A7
2
3
4
5 6 2
1
2 3
4 3
42
1
DI-124
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
1996 TERCEL (RM440U)
3 Check ABS control relay.
CHECK:
Check the continuity between each terminal of the ABS control
relay.
OK:
Terminals A6-3 and A6-4Continuity
(Reference value 62 W)
Terminals A6-1 and A6-2Open
CHECK:
(a) Apply battery voltage between terminals A6-3 and A6-4.
(b) Check the continuity between terminals of the ABS con-
trol relay.
OK:
Terminals A6-1 and A6-2Continuity
NG Replace ABS control relay.
OK
4 Check for open and short in harness and connector between ABS control relay
and ABS ECU (See page IN-26).
NG Repair or replace harness or connector.
OK
If same code is still output after DTC is deleted, check contact condition of each connection. If
connections are normal, ECU may be defective.

- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
DI-125
1996 TERCEL (RM440U)
DTC 21, 22, 23, 24 ABS Actuator Solenoid Circuit
CIRCUIT DESCRIPTION
This solenoid goes on when signals are received from the ECU and controls the pressure acting on the brake
cylinders, thus controlling the braking force.
DTC No.DTC Detecting ConditionTrouble Area
21
Conditions 1 through 3 continue for 0.05 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage:
Battery positive voltage
2. Voltage or ABS ECU terminal AST:
Battery positive voltage
3. When power transistor of ECU is ON, voltage of terminal
SFR is 0 V or battery positive voltage

ABS actuator

Open or short in SFR circuit

ECU
22
Conditions 1 through 3 continue for 0.05 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage:
Battery positive voltage
2. Voltage or ABS ECU terminal AST:
Battery positive voltage
3. When power transistor of ECU is ON, voltage of terminal
SFL is 0 V or battery positive voltage

ABS actuator

Open or short in SFL circuit

ECU
23
Conditions 1 through 3 continue for 0.05 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage:
Battery positive voltage
2. Voltage or ABS ECU terminal AST:
Battery positive voltage
3. When power transistor of ECU is ON, voltage of terminal
SRR is 0 V or battery positive voltage

ABS actuator

Open or short in SRR circuit

ECU
24
Conditions 1 through 3 continue for 0.05 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage:
Battery positive voltage
2. Voltage or ABS ECU terminal AST:
Battery positive voltage
3. When power transistor of ECU is ON, voltage of terminal
SRL is 0 V or battery positive voltage

ABS actuator

Open or short in SRL circuit

ECU
Fail safe function:
If trouble occurs in the actuator solenoid circuit, the ECU cuts off current to the ABS control (solenoid) relay
and prohibits ABS control.
DI4LW-03

W00705F15132
22
1 2ABS
Battery
B-Y
B
Fuse
Block
W-B
EA
EB
1
W-B
11
W-B
2
2 5
4 L
66
14
DLC1
ABS Control
Relay
Solenoid
Relay
P
R-B
R-W
L-W
G-Y
ABS ECUABS ECU
7 3
8 4
5 1
121 2
SFLR
SFLH
SFRR
SFRH
SRRR
SRRH A6
A5A13
A7 A7
A7
A6A13
A12
A12
A12
A12
Y-R
F7Y
F6Engine Room R/B
L
W-B
W-B
SRLR SRLH A13
A13
B-R
1ABS ECU
ABS ECU
ABS ECU
A4
A4
A4
A4
A4
A4
A4
A4
A5
A56Y
Y
Y-R
Y-R
Y-B Y-B
5
2
15
11
MAIN
FL
ALT
EA2
IC2IE1
IE1 IC2
IC2IE1
IE1 IC2
6
1
14
2
5
43
13 2
ABS Actuator LMotor
Relay
2
G-Y
Y-B
G-Y
Monitor
L-WL-R
R14675
4321
5 6 7 8
4
A5 A4
4321
5 6 7 8
4
A5 A4
4321
5 6 7 8
4
A5 A4
4321
5 6 7 8
4
A5 A4
4321
5 6 7 8
4
A5 A44321
5 6 7 8
4
A5 A4
DI-126
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
1996 TERCEL (RM440U)
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check ABS actuator solenoid.
PREPARATION:
Disconnect the 2 connectors from the ABS actuator.
CHECK:
Check the continuity between terminals A5-4 and A4-1, 2, 3,
4, 5, 6, 7, 8 of the ABS actuator connector.
OK:
Continuity
HINT:

Resistance of each of the solenoids SFRH, SFLH, SRRH
and SRLH is 5.0 W.

Resistance of each of the solenoids SFRR, SFLR, SRRR
and SRLR is 2.2 W.
NG Replace ABS actuator.
OK