TOYOTA PRIUS 2001 Service Repair Manual

DI±856
± DIAGNOSTICSNAVIGATION SYSTEM
2001 PRIUS (RM778U)
Replace or repair wire harness.

± DIAGNOSTICSNAVIGATION SYSTEM
DI±863
2001 PRIUS (RM778U)
27. No AM, FM or CD screen is displayed.
INSPECTION PROCEDURE
1 Check the sound. (Check if the sound of the radio, cassette or CD can be heard.)
OK System check mode. (Check radio receiver as-
sembly)
NG
2 Check the radio receiver assembly.
PREPARATION:
Disconnect the radio receiver assembly connector.
CHECK:
Check voltage terminals +B.
OK:
+B: 10 ± 14 V
CHECK:
Check voltage terminal ACC when turn ignition switch ACC or ON position.
OK:
ACC: 10 ± 14 V
CHECK:
Check continuity terminal GND.
OK:
GND: Continuity
NG Replace or repair wire harness.
OK
DI7PK±01

DI±864
± DIAGNOSTICSNAVIGATION SYSTEM
2001 PRIUS (RM778U)
3 Check ºAVC±LAN communication circuitº (See page DI±860).
NG Replace or repair AVC±LAN circuit.
OK
Replace the radio receiver assembly.

I11572
Radio Receiver Assembly Multi Display Navigation ECU
Terminator
± DIAGNOSTICSNAVIGATION SYSTEM
DI±865
2001 PRIUS (RM778U)
AVC±LAN (Communication bus) Circuit
CIRCUIT DESCRIPTION
Each unit of navigation system connected with AVC±LAN (communication bus) transfers the signal of each
switch by communication.
When +B short and GND short occur in this AVC±LAN, navigation system will not function normally as the
communication is discontinued.
In this AVC±LAN, multi display becomes the master of the communication, and the radio receiver assembly
has a terminator necessary for transmitting the communication.
multi display is connected between navigation ECU and radio receiver assembly, navigation system has the
structure that makes communication impossible without navigation ECU, multi display or radio receiver as-
sembly.
AVC±LAN
DI7PL±01

I15473
Navigation ECU Multi Display
Radio receiver assemblyR G
N3 10
TX1±
TX1+
AUO+
AUO±
AUI± G 7
M6
N35
IJ16
RG
5
M6 TX1±
TX+TX± TX1+
10
M5
3
M5RG
N22
G P
IJ26
IG13
V4
R7
R
N211
N2
1
AUI+ N210
V
P 9
IJ28 V 6
R32 F14
Front
Door
Speaker
LH2
FL±
TX+
R4
9
FL+ TX±10
10
R4 R
G C
F C
F
J26
J/C C7
Center Cluster SW
7
8CF
R
G TX+
TX±AVC±LAN circuit
P R3IJ2 IJ2 IG1 1IJ1 DI±866
± DIAGNOSTICSNAVIGATION SYSTEM
2001 PRIUS (RM778U)
WIRING DIAGRAM

± DIAGNOSTICSNAVIGATION SYSTEM
DI±867
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check wire harness and connector between radio receiver assembly and naviga-
tion ECU (See page IN±41).
NG Repair or replace wire harness or connector be-
tween radio receiver assembly and navigation
ECU.
OK
2 Check wire harness and connector between multi display and navigation ECU
(See page IN±41).
NG Repair or replace wire harness or connector be-
tween multi display and navigation ECU.
OK

I12172
Navigation ECUMulti DisplayRadio Receiver
Assembly
SST
TX± TX+TX± TX+
Radio receiver assembly connector ºR4º
DI±868
± DIAGNOSTICSNAVIGATION SYSTEM
2001 PRIUS (RM778U)
3 Skip radio receiver assembly and check AVC±LAN.
PREPARATION:
(a) Connect Multi Display connector.
(b) Disconnect radio receiver assembly ºR4º connector.
(c) Using SST (Navigation Check Wire P/N 09843±18050),
connect the terminal TX+ to terminal TX± of ºR4º connec-
tor of radio receiver assembly.
CHECK:
Operate the panel switch and the touch switch of the display
and check that the navigation functions.
(Check that AVC±LAN is recovered.)
OK Replace the radio receiver assembly.
NG
Replace the Navigation ECU.

DI7S1±01
AT0716
0.5 Seconds
0.5 Seconds ON
OFF
With in 5 sec. after turning the ignition on,
press the A/C switch 3 times and turn the
blower switch from OFF to AUTO.
Indicator check (See step 3)
Actuator check (See step 5)
Cancel check mode and can start
A/C control.If both A/C switch and blower
switch are not operated.
: Indicates a blower switch operation
DTC check (See step 4)
Actuator check (See step 5)
After indicators blink 4 times
Auto
Except Auto
Except AutoAuto
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±871
2001 PRIUS (RM778U)
PRE±CHECK
1. WARNING FOR A/C COMPRESSOR LOCK
If compressor lock occurs during A/C operation, the A/C switch
indicator on the A/C control assembly starts blinking.
When this occurs, check for compressor lock (DTC 22) using
diagnosis trouble code check then proceed to inspect the circuit
or the component.
Compressor lock sensor circuit. " (See page DI±891)
2. LIST OF OPERATION METHODS
By operating each of the A/C control switches as shown in the diagram below, it is possible to enter the diag-
nosis check mode.

I18151
Blower Switch
A/C Switch
I00339
Blinking Pattern
4 times
1 sec.
1 sec.
ON
OFF
ON
OFF
ON
OFF1 sec.
0.5 sec.
0.5
sec.1.5 sec 2.5 sec. 1.5 sec. No Malfunction
Malfunction Detected
u "
4.5 sec.
Repeat DI±872
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
3. INDICATOR CHECK
(a) Within 5 sec. after turning the ignition switch on, press the
A/C switch 3 times and turn the blower switch from OFF
to AUTO.
(b) Check that all the indicators light up and go off at 1 second
intervals 4 times in succession.
HINT:

After the indicator check is ended, the system enters the
DTC begins automatically.

Operate the blower switch from AUTO to except AUTO
position when desiring to cancel the check mode.
4. DTC CHECK (SENSOR CHECK)
(a) Perform an indicator check. After the indicator check is
completed, the system enters the DTC check mode auto-
matically.
(b) Read the DTC as indicated by the number of blinks of the
A/C indicator.
HINT:
The illustration shows the blinking pattern associated with the
DTC 12 and 23. If 2 or more DTCs (abnormalities) are indicated,
the lowest number (code) is output first.
(c) Identify the problem using the chart of the DTC.

I18151
Blower Switch
Max. Cool e
20.5 (66)
Step
No.Temp. setting
°C (°F)Blower Level Air Mix Damper
R/F
(102.0 %)ON Air Inlet
DamperAir Outlet
DamperCompressor
1
2
3
4
521.0 e 23.5
(67 e72)
24.0 e 26.0
(73 e77)
26.5 e 29.0
(78 e83)
29.5 (84)
eMax. Warm4
" "
17
31
"
"
50 %
(Cool/Warm)±10 %
(Cool)
100 %
(Warm)REC
(±1 %)
R/F
(82.0 %)
FRS
(110.0 %)
FRS
(110.0 %) DEF
(110 %)FOOT
(50 %)
F/D
(90 %) B/L
(15 %) FACE
(±10 %)
OFF
" "
"
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±873
2001 PRIUS (RM778U)
5. ACTUATOR CHECK
(a) Actuator check mode is started at the same time with DTC
check mode.
(b) Check visually on by hand that the air flow, amount of
damper operating and operation of the compressor
changes according to the set temperature of the A/C con-
trol panel, as shown in the chart.
HINT:
To cancel the check mode, turn blower switch from AUTO to ex-
cept AUTO.