2001 TOYOTA PRIUS Service Repair Manual

F12444
ON
WA
B11
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
DI±441
2001 PRIUS (RM778U)
5 Check battery positive voltage.
CHECK:
Check the battery positive voltage.
OK:
Voltage: 10 ± 14 V
NG Check and repair charging system (See page
HV±39).
OK
6 Check operation of the ABS warning light.
In case of using the TOYOTA hand±held tester:
PREPARATION:
(a) Connect the TOYOTA hand±held tester to the DLC3.
(b) Turn the ignition switch ON, and push the TOYOTA hand±held tester main switch ON.
(c) Select the ACTIVE TEST mode on the TOYOTA hand±held tester.
CHECK:
Check that ºONº and ºOFFº of the ABS warning light can be shown on the combination meter by the TOYOTA
hand±held tester.
In case of not using the TOYOTA hand±held tester:
(a) Disconnect the connector (B11) from the brake ECU.
(b) Using service wire, connect terminal WA of brake ECU
harness side connector and body ground.
(c) Turn the ignition switch ON.
OK:
ABS warning light goes off.
OK Check and replace brake ECU.
NG
Check for short circuit in harness and connector between combination meter and brake ECU,
combination meter and DLC3 (See page IN±41).
Check ABS solenoid relay circuit (See page DI±376).

F12683
Brake ECU
Instrument Panel J/B GAUGE 4
IH L FL Block No. 1
1
BatteryIgnition Switch
2
2
2K2A18
W
3AM1IP1
AABS
2A14 2B F11
C10
J11
J/CB±W
5WA
W±B W±G
2H 2D DC/DC
B±Y
1
FL Block
No. 2 B±G
F131
B11
1C10
C10L2
10
22
5 1
3
6
87
LCommbination
Mater
2B 6
IDBR MAIN DI±442
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)
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.
Connect terminals Tc and CG of the DLC3 to make the ABS warning light blink and output the DTC.
WIRING DIAGRAM
DI29F±14

± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
DI±443
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
HINT:
Troubleshoot in accordance with the chart below for each trouble symptom.
ABS warning light does not light up*1
ABS warning light remains on*2
*1: Start the inspection from step 1 in case of using the TOYOTA hand±held tester and start from step 2 in
case of not using TOYOTA hand±held tester.
*2: After inspection with step 4, start the inspection from step 5 in case of using the TOYOTA hand±held
tester and start from step 6 in case of not using TOYOTA hand±held tester.
1 Check operation of the brake warning light.
PREPARATION:
(a) Connect the TOYOTA hand±held tester to the DLC3.
(b) Turn the ignition switch ON, and push the TOYOTA hand±held tester main switch ON.
(c) Select the ACTIVE TEST mode on the TOYOTA hand±held tester.
CHECK:
Check that ºONº and ºOFFº of the ABS warning light can be shown on the combination meter on the TOYOTA
hand±held tester.
OK Check and replace brake ECU.
NG
2 Check ABS warning light.
See combination meter troubleshooting on page BE±2.
NG Repair bulb or combination meter assembly.
OK

F00043
1 2 3
4 5 6
1 2 3
4 5 6
1 2 3
4
65 Open
Continuity
Continuity
Continuity
Open
(+)(±)
(+) (±)1 2 3
4 5 6 Continuity
DI±444
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)
3 Check ABS solenoid relay.
PREPARATION:
Remove the ABS solenoid relay from engine room R/B No. 3.
CHECK:
Check continuity between each terminal of ABS solenoid relay.
OK:
Terminals 4 and 6Continuity (Reference value 80 W)
Terminals 2 and 3Continuity
Terminals 1 and 3Open
CHECK:
(a) Apply battery positive voltage between terminals 4 and 6.
(b) Check continuity between each terminal of ABS solenoid
relay.
OK:
Terminals 2 and 3Open
Terminals 1 and 3Continuity
CHECK:
Connect the
test lead to terminal 5 and the  lead to terminal
3. Check continuity between the terminals.
OK:
Continuity
If there is no continuity, connect the  test lead to terminal 5
and the
lead to terminal 3. Recheck continuity between ter-
minals.
NG Replace ABS solenoid relay.
OK
Repair or replace and check for open circuit in harness and connector between DLC3 and ABS
solenoid relay and body ground (See page IN±41).