1996 TOYOTA LAND CRUISER ECU

W02195
ECU−IG
Ignition Switch
GNDABS ECU
B−W
J6
Junction
Connector
W
B−L
6
EA2
AM1
IE
3 4
Deceleration
Sensor
2
2
2
2 2
2
2
A13
A13 A13
Battery
AM1
GND
B−W
B−Y
B
B
BB
B
BR BR
BR
F6 1
1
13
+B
12
15
4 R/B No. 2
R/B No. 2
−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
DI−225
1996 LAND CRUISER (RM451U)
DTC Always ON Malfunction in ECU
IG Power Source Circuit
CIRCUIT DESCRIPTION
This is the power source for the ECU, hence the CPU, and the actuator.
DTC No.DTC Detecting ConditionTrouble Area
Alway ONVoltage of ECU terminal +B remains at more than 17 V or
below 9.5 V
Battery
 IC regulator
 Open or short in power source circuit
 ECU
Fail safe function:
If trouble occurs in the power source circuit, the ECU cuts off current to the ABS control (solenoid) relay and
prohibits ABS control.
WIRING DIAGRAM
DI5ME−03
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DI−226
−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
1996 LAND CRUISER (RM451U)
INSPECTION PROCEDURE
1 Is DTC output?
Check DTC on page DI−190 .
YES Repair circuit indicated by code output.
NO
2 Is normal code displayed?
YES Check ABS solenoid relay. Check for short in harness and connector between ABS solenoid
relay and DLC1 (See page IN−28 ).
NO
3 Is ABS warning light go off?
YES Check for open or short in harness and connec-
tor between ECU−IG fuse and ECU (See page
IN−28 ).
NO
4 Check battery positive voltage.
PREPARATION:
Start the engine.
CHECK:
Check the battery positive voltage.
OK:
Voltage: 10 − 16 V NG Check and repair charging system.
OK
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−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
DI−227
1996 LAND CRUISER (RM451U)
5 Check ABS warning light.
PREPARATION:
(a) Turn the ignition switch OFF.
(b) Disconnect the connector from the ABS ECU.
(c) Turn the ignition switch ON.
CHECK:
Check the ABS warning light goes off.
OK Check and replace ABS ECU.
NG
Check for short in harness and connector between combination meter and ABS EC\
U, and com-
bination meter and DLC1 (See page IN−28).
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W02198
1
STOP
G−O2
G−W
G−W
G−W
W−B 6
3
Stop Light
A12STP ABS ECU
ID2
Stop light Switch
High Mounted
Stop Light 2
BG
G−W
G−W
G−W
BQ1
2
DI−228
−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
1996 LAND CRUISER (RM451U)
Stop Light Switch Circuit
CIRCUIT DESCRIPTION
This stop light switch senses whether the brake pedal is depressed or releas\
ed, and sends the signal to the
ECU.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check operation of stop light.
CHECK:
Check that stop light lights up when brake pedal is depressed and turns off when brake pedal is released.
NG Repair stop light circuit (See page BE−24).
OK
DI5MG−02
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BE6653
R14209
F15325
(−) (+)STP
−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
DI−229
1996 LAND CRUISER (RM451U)
2 Check voltage between terminal STP of ABS ECU and body ground.
PREPARATION:
Remove the ABS ECU with connectors still connected.
CHECK:
Measure the voltage between terminal STP of the ABS ECU
and body ground when the brake pedal is depressed.
OK:
Voltage: 8 − 14 V
OK Proceed to next circuit inspection shown on problem symptoms table (See page DI−200 ).
NG
3 Check for open in harness and connector between ABS ECU and stop light switch (See page IN−28 ).
NG Repair or replace harness or connector.
OK
Check and replace ABS ECU.
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W02199
BatteryJunction
Connector
ID
W−B
B−W
ABS Control Relay
1 4
2
6 3
1
4
Motor
Relay
Solenoid
Relay
ABS ECU
ABS ECU
ABS Actuator 4
5
A7
A6
A6 A6
A4 R−L
R−L
DLC1
Short Pin
B−W
IH1
A12
ABS ECU
W
13
C10
GAUGE
2223 ABS
Warning
Light
A
A
J1
C10IH1
20
A7
A7A7
A7
EA3
EA3
2
1 B−W
B−W
B−L OO
O
Y
54
3
23 OY
DI−230
−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
1996 LAND CRUISER (RM451U)
ABS Warning Light Circuit
CIRCUIT DESCRIPTION
If the ECU detects trouble, it lights the ABS warning light while at the same time prohibiting ABS control. At
this time, the ECU records a DTC in memory. After removing the short pin of the DLC1, connect terminals
Tc and E
1 of the DLC1 to make the ABS warning light blink and output the DTC.
WIRING DIAGRAM
INSPECTION PROCEDURE
Troubleshooting in accordance with the chart below for each trouble symptom.
ABS warning light does not light upGo to step 1
ABS warning light remains onGo to step 3
1 Check ABS warning light.
See Combination Meter Troubleshooting on page BE−2.
NG Repair bulb or combination meter assembly.
OK
DI5MJ−03
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Version 1.11 - 03/16/2010

DI−232
−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
1996 LAND CRUISER (RM451U)
3 Is DTC output?
Check DTC on page DI−190 .
YES Repair circuit indicated by code output.
NO
4 Does ABS warning light go off if short pin is removed?
NO Check for short in harness and connector be- tween warning light and DLC1 and ECU (See
page IN−28 ).
YES
5 Check ABS control relay (See step 2).
NG Replace ABS control relay.
OK
Check for short in harness and connector be-
tween DLC1 and ABS control relay (See page
IN−28 ).
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W02200
BR−BE1Tc
3 11
DLC1
B−YIH1 ABS ECU
Tc 12 VA13
5
EC
B−Y
11
F00007
Tc
DLC1
E1
−
DIAGNOSTICS ANTI−LOCK BRAKE SYSTEM
DI−233
1996 LAND CRUISER (RM451U)
Tc Terminal Circuit
CIRCUIT DESCRIPTION
Connecting terminals Tc and E1 of the DLC1 causes the ECU to display the DTC by flashing the ABS warni\
ng
light.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check voltage between terminals Tc and E1 of DLC1.
CHECK:
(a) Turn the ignition switch ON.
(b) Measure the voltage between terminals Tc and E
1 of the
DLC1.
OK:
Voltage: 10 − 14 V
OK If ABS warning light does not blink even after Tc and E
1 are connected, ECU may be defective.
NG
DI5ML−02
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