Page 961 of 2543
DTC 41 IG Power Source Circuit
CIRCUIT DESCRIPTION
This is the power source for the ECU, hence the CPU and the actuators.
DTC No. Diagnostic Trouble Code Detecting Condition` Trouble area
41
When either of the following (1) or (2) is
detected:
(1) Voltage at ECU terminal IG1 is less than
9.5 V for more than 10 sec. while vehicle
speed is 3 km/h (1.9 mph) or more.
(2) Voltage at ECU terminal IG1 is more than
17 V for more than 1.2 sec.
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 solenoid relay
and prohibits ABS control.
BR±92± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)
Page 962 of 2543
Check battery positive voltage.
Remove ABS (& TRAC) ECU with connectors still
connected.
1. Turn ignition switch ON.
2. Measure voltage between terminals IG1 and
GND of ABS (& TRAC) ECU connector.
Voltage: 10 Ð 14 V
Check and repair the charging system.
Voltage: 10 Ð 14 V
Check voltage between terminals IG1 and GND of ABS (& TRAC) ECU
connector.
Check and replace ABS (& TRAC) ECU.
INSPECTION PROCEDURE.
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)BR±93
Page 963 of 2543
Check continuity between terminal GND of ABS (& TRAC) ECU
connector and body ground.
Measure resistance between terminals GND of
ABS (& TRAC) ECU connector and body ground.
Resistance: 1 or less
Check for short in all the harness and
components connected to ECU±IG fuse
(See attached wiring diagram).
Repair or replace harness or connector.
Check ECU±IG fuse.
Check for open in harness and connector be-
tween ABS (& TRAC) ECU and battery (See page
IN±30).
Remove ECU±IG fuse from J/B No. 1.
Check continuity of ECU±IG fuse.
Continuity BR±94
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)
Page 964 of 2543
DTC 44 Lateral Acceleration Sensor Circuit
CIRCUIT DESCRIPTION
This sensor detects acceleration acting laterally on the vehicle. The sensor signal is used in ABS control. If the
sensor functions abnormally, the ABS warning light comes on but the ABS still operates.
DTC No.
Diagnostic Trouble Code Detecting Condition
Trouble area
44
Either of the following (1) or (2) is detected:
(1) An open or short is detected in circuit
GS1 or GS2 for 1 sec.
(2) After the ignition is turned ON, the test
signal is output by GST. During this time,
a trouble signal is detected for 0.5 sec.
Lateral acceleration sensor
Open or short in lateral acceleration sensor circuit
ECU
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)BR±95
Page 965 of 2543
Check for open and short in harness and connector between sensor and
ECU (See page IN±30).
1. Remove ABS (& TRAC) ECU with connec±
tors still connected.
1. Disconnect sensor connector.
3. Turn ignition switch ON.
Measure voltage between terminals GS1, GS2,
GST of ECU and body ground.
Voltage:
GS1, GS2: 10 Ð 14 V
GST: As shown below
Check voltage between terminals GS1, GS2, GST of ECU and body ground.
Repair or replace harness or connector.
Check and replace ABS (& TRAC) ECU.
Check and replace lateral acceleration sensor.
INSPECTION PROCEDURE.
BR±96± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)
Page 966 of 2543
DTC 51 ABS Pump Motor Lock
CIRCUIT DESCRIPTION
DTC No.
Diagnostic Trouble Code Detecting Condition
Trouble area
51
Pump motor is not operating normally during
initial check.
ABS pump motor
Fail safe function: If trouble occurs in the ABS pump motor, the ECU cuts off the current to the solenoid relay
and prohibits ABS control.
WIRING DIAGRAM
See page BR±72
INSPECTION PROCEDURE
See inspection of ABS actuator (See page BR±44).
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)BR±97
Page 967 of 2543
DTC 55 Brake Fluid Level Warning Switch Circuit
CIRCUIT DESCRIPTION
The brake fluid level warning switch sends the appropriate signal to the ECU when the brake fluid level drops.
DTC No. Diagnostic Trouble Code Detecting Condition Trouble area
55
Voltage at ECU terminal LBL is 0 V
continuously for 10 sec. or more.
Brake fluid level
Brake fluid level warning switch
Short in brake fluid level warning switch circuit
ECU
Fail safe function: If trouble occurs in this circuit, the ECU cuts off current to the TRAC solenoid relay and prohib-
its TRAC control. BR±98
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)
Page 968 of 2543
Check brake fluid level.
Check brake fluid level warning switch.
Check and repair brake fluid leakage and
add fluid.
Replace brake fluid level warning switch.
Repair or replace harness or connector.
Check and replace ABS & TRAC ECU.
Check for short in all the harness and components connected to brake fluid
level warning light (See page IN±30).
See page BE±52.
Check the amount of fluid in the brake reservoir.
± BRAKE SYSTEMANTI±LOCK BRAKE SYSTEM (ABS)BR±99