Page 970 of 1943
F12445
Engine Room R/B No. 3
ABS No. 4
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
DI±393
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check ABS No. 4 fuse.
PREPARATION:
Remove the ABS No. 4 fuse from engine room R/B No. 3.
CHECK:
Check continuity of ABS No. 4 fuse.
OK:
Continuity
NG Check for short circuit in all the harness and
components connected to ABS No. 4 fuse (See
attached wiring diagram).
OK
2 Check battery positive voltage.
OK:
Voltage: 10 ± 14 V
NG Check and repair the charging system (See
page HV±39).
OK
Page 980 of 1943
F12428
Instrument Panel J/B
ECU±IG
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
DI±403
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check ECU±IG fuse.
PREPARATION:
Remove the ECU±IG fuse from instrument panel J/B.
CHECK:
Check continuity of ECU±IG fuse.
OK:
Continuity
NG Check for short circuit in all the harness and
components connected to ECU±IG fuse (See
attached wiring diagram).
OK
2 Check battery positive voltage.
OK:
Voltage: 10 ± 14 V
NG Check and repair the charging system (See
page HV±39).
OK
Page 1013 of 1943
F12428
Instrument Panel J/B
ECU±IG
DI±436
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check ECU±IG fuse.
PREPARATION:
Remove the ECU±IG fuse from instrument panel J/B.
CHECK:
Check continuity of ECU±IG fuse.
OK:
Continuity
NG Check for short circuit in all the harness and
components connected to ECU±IG fuse (See
attached wiring diagram).
OK
2 Check battery positive voltage.
OK:
Voltage: 10 ± 14 V
NG Check and repair the charging system (See
page HV±39).
OK
Page 1016 of 1943
DI±440
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check that brake ECU connectors are securely connected to brake ECU.
NO Connect connectors to brake ECU.
YES
2 Is DTC output?
Check DTC on page DI±353.
YES Repair circuit indicated by output code.
NO
3 Is normal code displayed?
YES Check ABS solenoid relay. Check for short cir-
cuit in harness and connector between ABS so-
lenoid relay and DLC3 (See page IN±41).
NO
4 Does ABS warning light go off?
YES Check for open or short circuit in harness and
connector between ECU±IG fuse and brake ECU
(See page IN±41).
NO
Page 1050 of 1943
F12823
ECU±IG Fuse
Instrument Panel J/B
DI±482
± DIAGNOSTICSELECTRIC MOTOR POWER STEERING
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check ECU±IG fuse.
PREPARATION:
Remove the ECU±IG fuse from the instrument panel J/B.
CHECK:
Check the continuity of the ECU±IG.
OK:
Continuity
NG Check for short circuit in all harness and com-
ponents connected to ECU±IG fuse (See at-
tached wiring diagram).
OK
2 Check that the battery positive voltage when IG switch is OFF.
OK:
Voltage: 9 ± 14 V
NG Charge or replace the battery.
OK
Page 1051 of 1943
F12824
ONIG
PGND
F12825
LOCK
PGND
± DIAGNOSTICSELECTRIC MOTOR POWER STEERING
DI±483
2001 PRIUS (RM778U)
3 Check voltage between terminals IG and PGND of EMPS ECU connector.
PREPARATION:
Remove the EMPS ECU with connectors still connected.
CHECK:
Turn the ignition switch ON and measure the voltage between
terminals IG and PGND of EMPS ECU connector.
OK:
Voltage: 9 ± 14 V
OK Check and replace the EMPS ECU.
NG
4 Check continuity between terminals PGND of EMPS ECU connector and body
ground.
CHECK:
Measure the resistance between terminals PGND of EMPS
ECU connector and body ground.
OK:
Resistance: 1 W or less
NG Repair or replace harness or connector.
OK
Check for open and short circuit in harness and connector between EMPS ECU and ECU±IG fuse
(See page IN±41).
Page 1054 of 1943
F12862
Engine Room
R/B No. 3
EMPS
Fuse
DI±486
± DIAGNOSTICSELECTRIC MOTOR POWER STEERING
2001 PRIUS (RM778U)
3 Check EMPS fuse.
PREPARATION:
5/18/01Remove the EMPS fuse from engine room R/B No. 3.
CHECK:
5/18/01Check continuity of EMPS fuse.
OK:
Continuity
NG Check for short circuit in harness and all com-
ponents connected to EMPS fuse (See attached
wiring diagram).
OK
Check for open and short circuit in harness and connector between EMPS ECU and battery
(See page IN±41).
Page 1057 of 1943
F12863
Instrument
Panel J/BECU±B
Fuse
DI±490
± DIAGNOSTICSELECTRIC MOTOR POWER STEERING
2001 PRIUS (RM778U)
NG Replace EMPS relay.
OK
3 Check ECU±B fuse.
PREPARATION:
Remove the ECU±B fuse from instrument panel J/B.
CHECK:
Check the continuity of ECU±B fuse.
OK:
Continuity
NG Check for short in harness and all components
connected to ECU±B fuse (See attached wiring
diagram).
OK
Check for open and short circuit in harness and connector between EMPS ECU and battery
(See page IN±41).