Page 1452 of 1943
I18396
Engine Room R/B No. 3
HTR3 Fuse
Z18060
15 2
3
123 5
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±945
2001 PRIUS (RM778U)
3 Check HTR3 fuses.
PREPARATION:
Remove the HTR3 fuse from engine room R/B No. 3.
CHECK:
Check continuity of HTR1 and HTR2 fuses.
OK:
Continuity exists.
NG Check for short in all the harness and compo-
nents connected to the HTR1 and HTR2 fuses
(See attached wiring diagram).
OK
4 Check HTR3 relays.
PREPARATION:
Remove the HTR3 relays from engine room relay block No. 3.
CHECK:
Check continuity between each pair of terminals shown below
of magnetic clutch relay.
OK:
Tester connectionSpecified condition
1 ± 262.5 ± 90.9 W
3 ± 5No continuity
PREPARATION:
Apply battery positive (+) voltage between terminals 1 and 2.
CHECK:
Check continuity between terminals 3 and 5.
OK:
Continuity exists.
NG Replace HTR3 relay.
OK
Page 1453 of 1943
I18393
DI±946
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
5 Check harness and connector between A/C amplifier and HTR1 and HTR2 fuses
(See page IN±41).
NG Check and replace harness and connector.
OK
Check and replace A/C amplifier.
6 Check PTC heater.
PREPARATION:
Remove the heater radiator (See page AC±51).
CHECK:
Check continuity between terminals of PTC heater connector,
as shown in the chart.
OK:
Tester connectionResult
1 ± 2Continuity
3 ± 4Continuity
NG Replace heater radiator.
OK
Check harness and connector between PTC heater and HTR1, HT2 relays, PTC heater and body
ground (See page IN±41).
Page 1457 of 1943
I18396
Engine Room R/B No. 3
HTR1 Fuse HTR2 Fuse
Z18060
15 2
3
123 5
DI±950
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
3 Check HTR1 and HTR2 fuses.
PREPARATION:
Remove the HTR1 and HTR2 fuses from engine room R/B NO.
3.
CHECK:
Check continuity of HTR1 and HTR2 fuses.
OK:
Continuity exists.
NG Check for short in all the harness and compo-
nents connected to the HTR1 and HTR2 fuses
(See attached wiring diagram).
OK
4 Check HTR1 and HTR2 relays.
PREPARATION:
Remove the HTR1 and HTR2 relays from engine room relay
block NO. 3.
CHECK:
Check continuity between each pair of terminals shown below
of magnetic clutch relay.
OK:
Tester connectionSpecified condition
1 ± 262.5 ± 90.9 W
3 ± 5No continuity
PREPARATION:
Apply battery positive (+) voltage between terminals 1 and 2.
CHECK:
Check continuity between terminals 3 and 5.
OK:
Continuity exists.
NG Replace HTR1 and (or) HTR2 relay.
OK
Page 1555 of 1943

F12396
TOYOTA Hand±Held Tester
DLC3
SF1KO±01
B11794
7
3
Battery
B11816
B09225
Fuel Tube Connector
SF±6
± SFIFUEL PUMP
1220 Author: Date:
2001 PRIUS (RM778U)
FUEL PUMP
ON±VEHICLE INSPECTION
1. CHECK FUEL PUMP OPERATION
(a) Connect the TOYOTA hand±held tester to the DLC3.
(b) Turn the ignition switch ON and TOYOTA hand±held tes-
ter main switch ON.
NOTICE:
Do not start the engine.
(c) Select the active test mode on the TOYOTA hand±held
tester.
(d) Please refer to the TOYOTA hand±held tester operator's
manual for further details.
(e) If you have no TOYOTA hand±held tester, connect the
positive (+) lead from the battery to terminal 3 of the con-
necter, and the negative (±) lead to terminal 7.
(f) Check that there is pressure in the fuel inlet pipe from the
fuel line.
HINT:
If there is fuel pressure, you will hear the sound if fuel following.
If there is no pressure, check these parts, Fusible link, Fuses,
EFI Main relay, Fuel pump, ECM, and Witting connector.
(g) Turn the ignition switch to LOCK.
(h) Disconnect the TOYOTA hand±held tester from the
DLC3.
2. CHECK FUEL PRESSURE
(a) Check the battery positive voltage is above 12 V.
(b) Disconnect the negative (±) terminal cable from the bat-
tery.
(c) Purchase the new fuel tube and take out the fuel tube
connector from its pipe.
Part No.: 23901±21020
Page 1770 of 1943
I17787
Engine room J/B:
Fuses:
1. HTR Fuse
2. RDI Fuse
3. ABS No. 2 Fuse
4. CDS FAN Fuse
5. HORN Fuse
6. THRO Fuse
7. ABS No. 3 Fuse
8. TURN±HAZ Fuse
9. AM2 Fuse
10. BATT FANRelays:
A. FAN NO. 1 Relay
B. FAN NO. 2 Relay
C. FAN NO. 3 Relay
D. IG2 Relay
E. HORN Relay
F. HTR Relay
G. EFI Relay
H. CLR MG Relay
I. HEAD Relay
J. CIR OPN Relay
K. DIM Relay *1
123 4 5 6 7 8
91011
121314
1516
17
18 K
J
A B
C D E
F
G H
I
11. DOME Fuse
12. HEAD HI (RH) Fuse *1
13. HEAD HI (LH) Fuse *1
14. HEAD LO (LH) *1
HEAD (LH) *2
15. HEAD LO (RH) *1
HEAD (RH) *2
16. EFI Fuse
17. HEV Fuse
18. HEAD Fuse *1
*1: w/ Daytime Running Light
*2: w/o Daytime Running Light
± BODY ELECTRICALPOWER SOURCE
BE±13
1680 Author: Date:
2001 PRIUS (RM778U)
Page 1771 of 1943
I17788
Instrument Panel J/B:
Fuses: Relays:
A. IG1 Relay
B. ACC Relay
C. TAIL Relay
D. POWER Relay
E. DEF Relay
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15 A
B C
D
16
E
1. HTR Fuse
2. STOP Fuse
3. ECU±B Fuse
4. DOOR Fuse
5. OBDII Fuse
6. PWR1 Fuse
7. AM1 Fuse8. GAUGE Fuse
9. ECU±IG Fuse
10. WIPER Fuse
11. WASHER Fuse
12. PANEL Fuse
13. TAIL Fuse
14. ACC Fuse15. CIG Fuse
16. SRS ACC Fuse
17. PWR Fuse
18 DEF Fuse
1718 BE±14
± BODY ELECTRICALPOWER SOURCE
1681 Author: Date:
2001 PRIUS (RM778U)
Page 1772 of 1943
I17789
1 2 3456
7 A B
C
D E
Fuses: Relays: Engine Room R/B No. 3:
G H
1. HTR2 Fuse
2. HTR1 Fuse
3. ABS No. 4 Fuse
4. ABS No. 1 Fuse5. EMPS Fuse
6. HTR3 Fuse
7. DRL FuseA. A/C W/P Relay
B. ABS SOL Relay
C. DRL Relay
D. HTR2 RelayE. HTR1 Relay
G. HTR3 Relay
H. EPMS Relay
Engine Room R/B No. 2:
A B C
Relays:
A. IGCT Relay
B. HYDRO MTR No. 2 Relay
C. HYDRO MTR No. 1 Relay
± BODY ELECTRICALPOWER SOURCE
BE±15
1682 Author: Date:
2001 PRIUS (RM778U)