2001 TOYOTA PRIUS Service Repair Manual

I18388
A/C Amplifier
11
A7MPX+ GR
4
MPX+
BJ6
J/C
HTR Relay
J/C
Battery4
A7
MP2+ C11
Combination Meter
MPX±
11 GR±B
MPX1 MPX2
10
B8
14 13
11
B8 MPX+
MPX±
MPD2
MPD1
Instrument Panel J/B
HRLY6
2FL±O
BR R 4
1F
5 3
2
HTR
13
1J
8
1K
3
1B
3
1K
To Blower Motor
W13
IE1
R
A
J23
CJ22
R
FL Block
No. 1 DC/DC
B±G
F11 1
F13 1
1
MAINW±B
A F18
FL Block
No. 2
AWInstrument Panel J/B
1
2H
8
2K
IG1
Relay
3
25
1AM1
W±GI15
Ignition
SW
HTRAM1
3
2B
6
2D
3
2D
IG12
4
B±Y
J11
J/C
ID
IE W±BA
AJ1
J/C
3 2
E10 E10ECM
GR
GR±LC1
Gateway ECU
GR±B
J7 J/C
Engine Room J/B Body ECU DI±926
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
Heater Main Relay Circuit
CIRCUIT DESCRIPTION
The heater main relay is switched on by signals from the A/C amplifier. It supplies power to the blower motor.
WIRING DIAGRAM
DI7SK±01

BE1850 BE1844I00312125
3
125
3
4
4
I18394
Engine Room J/B
HTR
Fuse
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±927
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check heater main relay.
PREPARATION:
Remove heater main relay from engine room J/B.
CHECK:
Check continuity between each pair of terminals of heater main
relay shown below.
OK:
Tester connectionSpecified condition
1 ± 4No continuity
2 ± 4Continuity
3 ± 562.5 ± 90.9 W
PREPARATION:
Apply battery positive voltage between terminals 3 and 5.
CHECK:
Check continuity between each pair of terminal shown below.
OK:
Tester connectionSpecified condition
1 ± 2Continuity
2 ± 4No continuity
NG Replace hater main relay.
OK
2 Check HTR fuse
PREPARATION:
Remove HTR fuse from engine room J/B.
CHECK:
Check continuity of HTR fuse.
OK:
Continuity exists.
NG Check for short in all the harness and compo-
nents connected to the HTR fuse (See page
IN±41).
OK

DI±928
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
3 Check harness and connector between heater main relay and body ground, heat-
er main relay and body ECU (See page IN±41).
NG Check and replace harness and connector.
OK
Check multiplex communication system (See page DI±750).