Page 1055 of 1943
F12839
PIG
RLY E5
E61
2 B
GR IM1
IM21
7 B
GR 3
3 3
31 35
2 EMPS Relay
R±G B±R
Instrument Panel J/B
ECU±B
6
2G
2H1
W
F111
F101
WFL Block No. 1
DC/DC
F131
Engine Room R/B No. 3
3
321EMPS
FL Block No. 2 F18
MAIN
1
E52
PGND W±B
A J17
J/C
IG BatteryEngine Room R/B No. 3 DI±488
± DIAGNOSTICSELECTRIC MOTOR POWER STEERING
2001 PRIUS (RM778U)
DTC C1554/54 EMPS Relay Circuit
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1554/54Open or short circuit is detected.
EMPS ECU
EMPS relay
EMPS relay circuit
WIRING DIAGRAM
DI7RA±01
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).
Page 1058 of 1943
F12840
EMPS ECU
WL
E67
Y 3
IP1 L 11 Multiinformation Display
22
L
Instrument Panel J/B
IG1 Relay
3
51
2H GAUGE
2A5
W
FL Block No. 1
1
F11 F131
B±G
1 MAIN FL Block No. 2 F18
BatteryDC/DC
± DIAGNOSTICSELECTRIC MOTOR POWER STEERING
DI±491
2001 PRIUS (RM778U)
DTC C1556/56 P/S Warning Light Circuit
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1556/56There is a malfunction in PS warning light circuit.Multiinformation display
EMPS ECU
WIRING DIAGRAM
DI7RB±01
Page 1073 of 1943
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±509
2001 PRIUS (RM778U)DTC No.
(See Page)
Detection ItemTrouble AreaSRS
Warning Light
B0117/45
(DI±560)Short in side squib (LH) circuit
(to ground)Side airbag assembly LH (squib)
Airbag sensor assembly
Wire harness
Blink
B0118/46
(DI±563)Short in side squib (LH) circuit
(to B+)Side airbag assembly LH (squib)
Airbag sensor assembly
Wire harness
Blink
B0130/63
(DI±566)Short in P/T squib (RH) circuitSeat belt pretensioner RH (squib)
Airbag sensor assembly
Wire harness
Blink
B0131/64
(DI±570)Open in P/T squib (RH) circuitSeat belt pretensioner RH (squib)
Airbag sensor assembly
Wire harness
Blink
B0132/61
(DI±573)Short in P/T squib (RH) circuit
(to ground)Seat belt pretensioner RH (squib)
Airbag sensor assembly
Wire harness
Blink
B0133/62
(DI±576)Short in P/T squib (RH) circuit
(to B+)Seat belt pretensioner RH (squib)
Airbag sensor assembly
Wire harness
Blink
B0135/73
(DI±579)Short in P/T squib (LH) circuitSeat belt pretensioner LH (squib)
Airbag sensor assembly
Wire harness
Blink
B0136/74
(DI±583)Open in P/T squib (LH) circuitSeat belt pretensioner LH (squib)
Airbag sensor assembly
Wire harness
Blink
B0137/71
(DI±586)Short in P/T squib (LH) circuit
(to ground)Seat belt pretensioner LH (squib)
Airbag sensor assembly
Wire harness
Blink
B0138/72
(DI±589)Short in P/T squib (LH) circuit
(to B+)Seat belt pretensioner LH (squib)
Airbag sensor assembly
Wire harness
Blink
B1100/31
(DI±592)Airbag sensor assembly malfunctionAirbag sensor assemblyON
B1135/24
(DI±594)Harf connection in airbag sensor
assembly connectorAirbag sensor assembly
Wire harnessBlink
B1140/32
(DI±597)Side airbag sensor assembly (RH)
malfunctionSide airbag sensor assembly (RH)
Airbag sensor assembly
Wire harness
Blink
B1141/33
(DI±605)Side airbag sensor assembly (LH)
malfunctionSide airbag sensor assembly (LH)
Airbag sensor assembly
Wire harness
Blink
B1156/B1157/
15
(DI±613)Front airbag sensor (RH) malfunctionFront airbag sensor (RH)
Airbag sensor assembly
Instrument panel wire harness
Engine room No. 2 wire harness
ON
B1158/B1159/
16
(DI±621)Front airbag sensor (LH) malfunctionFront airbag sensor (LH)
Airbag sensor assembly
Instrument panel wire harness
Engine room main wire harness
ON
NlSystem normal±OFFNormal
(DI±629)Voltage source dropBattery
Airbag sensor assemblyON
Page 1196 of 1943
H15524
B±W
W5
2BB±O
GR
W±B ACC Relay 10A SRS ACC
5A AM1
FL Block No. 2 FL Block No. 1 15A AM2
Battery 100A
DC/DCB±G W±RA
J11
J/C W±G
W±R P±L1
2H
8
2C2
2E
4
2E
8
2K
2B 536
A18ACC
120A
1 1
F13 1
F12
1
F11 1B9 2
1J B1
2G2
2C ACC
2
67AM1
AM2 IG2MAIN
35
A18IG2 Airbag Sensor
Assembly Instrument Panel J/B
Ignition Switch
ID 12
3
Instrument Panel J/B Engine Room J/B DI±634
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
2001 PRIUS (RM778U)
DTC Normal Source Voltage Drop
CIRCUIT DESCRIPTION
The SRS is equipped with a voltage±increase circuit (DC±DC converter) in the airbag sensor assembly in
case the source voltage drops.
When the battery voltage drops, the voltage±increase circuit (DC±DC converter) functions to increase the
voltage of the SRS to normal voltage.
The diagnosis system malfunction display for this circuit is different from other circuits that is when the SRS
warning light remains lit up and the DTC is a normal code, source voltage drop is indicated.
Malfunction in this circuit is not recorded in the airbag sensor assembly, and the source voltage returns to
normal, the SRS warning light automatically goes off.
DTC No.Diagnosis
(Normal)Source voltage drop
WIRING DIAGRAM
DI6PY±07
Page 1199 of 1943
H15525
Combination Meter
Instrument Panel J/B
10A ACC
ACC Relay
5A AM1
W±G L15
C10
16
C10
5
C11
GR±RGR±R
W±BB±Y 9
2A
2
2D
8
2A
1
2H
8
2C
3
2B53
128
2K4
2B 1
2E3
A18LA
1
F11C
J27
Fl Block No. 1
23P±LW 1
F13
1 B±GL
GR±R
BBC
J28AB
A
J11
J/C
Battery F18
FL
Block
No. 2DLC3
DC/DC100A
J/C
I15 Ignition S/W
120A
MAINAirbag Sensor
Assembly
B±Y6
ID J26
J/C
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±637
2001 PRIUS (RM778U)
SRS Warning Light Circuit Malfunction
CIRCUIT DESCRIPTION
The SRS warning light is located on the combination meter.
When the SRS is normal, the SRS warning light lights up for approx. 6 seconds after the ignition switch is
turned from the LOCK position to ON position, and then turns off automatically.
If there is a malfunction in the SRS, the SRS warning light lights up to inform the driver of the abnormality.
When terminals Tc and CG of the DLC3 are connected, the DTC is displayed by blinking the SRS warning
light.
WIRING DIAGRAM
DI7QT±01
Page 1203 of 1943
H15526
J11
J/C AW±B 2KW±BJ24
J/C
W±BDLC3
P±BJ26
J/C
P±B
Tc
8 2D 8AA
413 CGTc
E
E19
A18
Instrument Panel J/BAirbag Sensor
Assembly
ID
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±641
2001 PRIUS (RM778U)
Tc Terminal Circuit
CIRCUIT DESCRIPTION
By connecting terminals Tc and CG of the DLC3 the airbag sensor assembly is set in the DTC output mode.
The DTCs are displayed by blinking the SRS warning light.
WIRING DIAGRAM
DI6Q0±06
Page 1211 of 1943
I15477
Instrument Panel J/B
FL Block No. 2S3
Stop Light SW I15
Ignition SW
Engine Room J/BHybrid Vehicle
Control ECU
J25 ID1B±Y
ST1± IG2 AM2
1G±W
2
R±B2
H14
STP 1
H14 B±W
34
6 B±W
J24
B C B±W W±R
7
6
2
2C
15A AM21
2GW±R
9
1J 2
1B B
1
F12B±G
120A MAIN
Battery1
F13
1
F18J15
D J14
E G±W
Instrument Panel J/B
9
2K15A STOP
W
100A DC/DC
F11 1
2H
FL Block No. 1
1
F131
B±GS3
Stop Light SW J/C
J/C
FL Block No. 1
± DIAGNOSTICSCRUISE CONTROL SYSTEM
DI±655
2001 PRIUS (RM778U)
WIRING DIAGRAM
