engine TOYOTA PRIUS 2001 Service Repair Manual

I17261
Gateway ECU
G1
GTX+MPD1
GTX±
MPD2
DI±766
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2001 PRIUS (RM778U)Symbols (Terminals No.)
Wiring ColorConditionSTD Value (V)
IG e GNDBYWBIgnition switch OFF or ACCBelow 1 VIG e GND
(2 e 14)B±Y e W±BIgnition switch ON10 ± 14 V
MDP1 (4)GR±BA/C ECU communication circuit±
GTX+ (5)RAVC±LAN communication circuit±
CG e Body ground
(7 e Body ground)W±B e
Body groundConstantBelow 1 V
BATT e GND
(8 e 14)R±G e W±BConstant10 ± 14 V
ACC e GNDGR RWBIgnition switch OFFBelow 1 VACC e GND
(9 e 14)GR±R e W±BIgnition switch ACC or ON10 ± 14 V
MDP2 (11)GR±LEngine and ECT ECU communication circuit±
GTX± (12)GAVC±LAN communication circuit±
GND e Body ground
(14 e Body ground)W±B e
Body groundConstantBelow 1 V

I15474
GR±B4 A7
A/C Amplifier C11
Combination MeterG1
Gateway ECU
B8
Body ECUE10
Engine Control Module
15MP2+
MPX+ GR4 11
3 2
MPX+MPX±
MPX+ MPX±
MPX2MPX1 GR±B
1613
GRGR±L11
14MPD1
MPD2
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±775
2001 PRIUS (RM778U)
DTC B1261 / 61 ECM communication stop
CIRCUIT DESCRIPTION
This DTC is output when communication stops between ECM and body ECU.
DTC No.DTC Detecting ConditionTrouble Area
B1261/61N i ti f ECM th 10 d
ECMB1261/61No communication from ECM more than 10 seconds.
ECM

Wireharness
WIRING DIAGRAM
DI1SV±05

DI±776
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check ECM.
CHECK:
Check that the engine starts normally.
HINT:
With this inspection, ECM CPU can be diagnosed if it works normally or not.
NG Replace the ECM.
OK

I15474
GR±B4 A7
A/C Amplifier C11
Combination MeterG1
Gateway ECU
B8
Body ECUE11
Engine Control Module
15MP2+
MPX+ GR4 11
3 2
MPX+MPX±
MPX1 MPX±
MPX2MPX1 GR±B
1613
GRGR±L11 14
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±779
2001 PRIUS (RM778U)
DTC B1266 / 66 Instrument panel system communica-
tion bus malfunction (+B short)
DTC B1267 / 67 Instrument panel system communica-
tion bus malfunction (GND short)
CIRCUIT DESCRIPTION
This DTC is output when +B or GND short occurs on instrument panel system communication bus. If +B or
GND short is detected on instrument panel system communication bus, separate it by bus cut relay in body
ECU to prevent while communication buses' failure.
WIRING DIAGRAM
DI7O3±01

± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±785
2001 PRIUS (RM778U)
DTC B1271 / 71 Combination meter ECU communica-
tion stop
CIRCUIT DESCRIPTION
This DTC is output when communication stops between combination meter ECU and body ECU.
DTC No.DTC Detecting ConditionTrouble Area
B1271/71No communication from Combination meter ECU more than 10
Combination meter ECUB1271/71No communication from Combination meter ECU more than 10
seconds.

Combination meter ECU

Wireharness
WIRING DIAGRAM
See page DI±770
INSPECTION PROCEDURE
1 Check combination meter ECU.
CHECK:
Start the engine and check that the speed meter and tacometer operate normally.
HINT:
With this inspection, the combination meter ECU CPU can be diagnosed if it works normally or not.
NG Replace the combination meter ECU.
OK
DI1SY±03

Mode Status
Error DB01 *2
(Communication
Control)Dual sound is detected.
Check harness for power supply
system of component shown by
auxiliary code.

Check harness for communica-
tion system of component shown by
auxiliary code.
Transmission
Error DC 01 *4
(Communication
Control)Transmission to component shown
by auxiliary code has been failed.
(This code does not necessarily
mean actual failure.)If same component shown by auxil-
iary code is recorded in other com-
ponent(s), check harness for power
supply and communication system
of components shown sub code.
Slave Reset
(Momentary
Interruption) DE 01 *5
(Communication
Control)After engine start, slave component
has been disconnected.
DB
Check harness for power supply
system of component shown by
auxiliary code.

Check harness for communica-
tion system of component shown by
auxiliary code.
No response to
connection
checkComponent shown by auxiliary
code is or was disconnected from
system after engine is started.
Component operated (sound and/
or image was provided) before en-
gine stop is or was disconnected
with ignition switch in ACC or ON.
Check harness for power supply
of component shown by auxiliary
code

Check harness for communica-
tion system of component shown
by auxiliary code D8
D9 Last Mode
Error
Check harness for power supply
of component shown by auxiliary
code

Check harness for communica-
tion system of component shown
by auxiliary code 01 *3
(Communication
Control)
01 *2
(Communication
Control)
Multiple Frame
Abort E4 01 *1
(Communication
Control)Since this DTC is provided for engi-
neering, it may be detected when
no actual failure exists. Multiple frame transmission is
aborted. Registered
component
disconnectedComponent shown by auxiliary
code is or was disconnected from
system with ignition switch in ACC
or ON.
Communication with component
shown by auxiliary code is not es-
tablished when engine is started.
Check harness for power supply
of component shown by auxiliary
code

Check harness for communica-
tion system of component shown by
auxiliary code D5 01 *2
(Communication
Control)
No Response
to ON/OFF
Instruction DA 01
(Communication
Control)No response is identified when
changing mode (audio and visual
mode change). Detected when
sound and picture does not change
by button operation.
Check harness for power supply
of component shown by auxiliary
code.

Check harness for communica-
tion system of component shown by
auxiliary code.

If error occurs again, replace
component shown by auxiliary
code.
*2: Even if no failure is detected, it may be stored depending on the battery condition or voltage for starting an engine.
*3: It is stored when 180 sec. has passed after the power supply connector is pulled out after engine start.
*4: It may be stored when the engine key is turned again 1 min. after engine start.
*5: It may be stored when the engine key is turned again after engine start. DI±814
± DIAGNOSTICSNAVIGATION SYSTEM
2001 PRIUS (RM778U)

Physical address: 190 Radio receiver assembly
Diagnosis item
ROM Error
Absence of
MasterDiagnosis contentCountermeasure and
inspected parts
Error is detected in internal ROM. Logical address
01
(Communication
Control)
01 *2
(Communication
Control)Component in which this code is re-
corded has been disconnected from
system with ignition in ACC or ON.
Or, when this code was recorded,
multi±display assembly was discon-
nected.
Check harness for power supply
system of multi display.

Check harness for communica-
tion system of multi display.

Check harness for power supply
system of radio receiver assembly.

Check harness for communica-
tion system of radio receiver as-
sembly.
DTC
21
D6Replace radio receiver assembly.
RAM Error Error is detected in internal RAM. 01
(Communication
Control)22Replace radio receiver assembly.
No Response
to Connection
Check 01 *3
(Communication
Control)Component shown by auxiliary code
is or had been disconnected from
system after engine start.
D9
Check harness for power supply
system of component shown by
auxiliary code.

Check harness for communica-
tion system of component shown by
auxiliary code. D8
Last Mode Error 01 *2
(Communication
Control)Component operated (sounds and/
or images were provided) before en-
gine stop is or has been discon-
nected with ignition switch in ACC or
ON.Check harness for power supply
system of component shown by
auxiliary code.
Check harness for communication
system of component shown by
auxiliary code. D9
No Response
to ON/OFF
Instruction
Mode Status
ErrorNo response is identified when
changing mode (audio and visual
mode change). Detected when
sound and picture does not change
by button operation. DA
DB 01
(Communication
Control)
01 *2
(Communication
Control)Dual alarm is detected.
Check harness for power supply
of component shown by auxiliary
code.

Check harness for communica-
tion system of component shown by
auxiliary code.
Check harness for power supply
of component shown by auxiliary
code.

Check harness for communica-
tion system of component shown by
auxiliary code.

If error occurs again, replace
component shown by auxiliary
code.
Transmission
Error DC 01 *4
(Communication
Control)Transmission to component shown
by auxiliary code has been failed.
(Detecting this DTC does not nec-
essary mean actual failure.)

If same auxiliary code is recorded
in other component, check harness
for power supply and communica-
tion system of components shown
sub code.
Master Reset
(Momentary
Interruption) DD 01 *5
(Communication
Control)After engine is started, multi±dis-
play assembly was disconnected
from system.
If this error occurs frequently, re-
place multi±display assembly.
± DIAGNOSTICSNAVIGATION SYSTEM
DI±815
2001 PRIUS (RM778U)

Slave Reset
(Momentary
Interruption) DE 01 *5
(Communication
Control)After engine is started, slave com-
ponent was disconnected from sys-
tem.
Check harness for power supply
of component shown by auxiliary
code.

Check harness for communica-
tion system of component shown by
auxiliary code.
Master Error DF 01 *6
(Communication
Control)Due to defective condition of multi
display, master function is switched
to audio equipment.
Error occurs in communication be-
tween sub±master (audio) and mul-
ti display.
Check harness for power supply
of multi±display assembly.

Check harness for communica-
tion system of multi±display assem-
bly.

Check harness for communica-
tion system between multi±display
assembly and sub±master compo-
nent.
Registration
Completion
Instruction
Error E0 01
(Communication
Control)ºRegistration Completion Instruc-
tionº command from multi display
cannot be received.
Since this DTC is provided for en-
gineering purpose, it may be de-
tected when no actual failure exists.
Audio
processor ON
error E1 01 *2
(Communication
Control)While source equipment is operat-
ing, AMP output is stopped.
Check harness for power supply
of multi±display assembly.

Check harness for communica-
tion system of multi±display assem-
bly.
ON/OFF
Instruction
Parameter
Error E2 01
(Communication
Control)Error occurs in ON/OFF controlling
command from multi±display as-
sembly.
Replace multi±display assembly.
Registration
Request
Transmission E3 01
(Communication
Control)Registration Request command is
output from slave component.
Receiving Connection Check
Instruction, Registration Request
command is output from sub±mas-
ter component.
Since this DTC is provided for en-
gineering purpose, it may be de-
tected when no actual failure exists.
Plural Frame
Abort E4 01
(Communication
Control)
Since this DTC is provided for en-
gineering purpose, it may be de-
tected when no actual failure exists. Plural frame transmission is
aborted.
AM Tuner Error 43 60
(Radio receiver
assembly)Replace radio receiver assembly. Abnormal condition is detected in
AM tuner.
Inspect radio receiver assembly.
FM Tuner Error 44 60
(Radio receiver
assembly)Replace radio receiver assembly.
Abnormal condition is detected in
FM tuner.
Mechanical or
Media Error 40 61
(Cassette
switch)Inspect cassette tape.
Malfunction due to mechanical fail-
ure is identified. Or, cassette tape is
cut or entangled.
EJECT
Malfunction 41 61
(Cassette
switch)Malfunction due to mechanical fail-
ure.Replace radio receiver assembly.
No Disc
Readout 42 62
(CD player)Disc cannot be read.Inspect CD.
CD Error 44 62
(CD player)Error is detected in CD player.Replace radio receiver assembly. DI±816
± DIAGNOSTICSNAVIGATION SYSTEM
2001 PRIUS (RM778U)

EJECT Error 45 62
(CD player)Magazine cannot be ejected.
Scratched/
Reversed Disc 46 62
(CD player)Scratches or dirt is found on CD sur-
face or CD is set upside down.Replace radio receiver assembly.
Inspect CD.
Physical address: 178 Navigation ECU
Gyro Error Error in gyro sensor is detected.
(Abnormal value in voltage output
from sensor is detected for more
than specified time.)
Check the Gyro voltage in the
diagnosis system mode. 10 58
(Navigation ECU)
Map Disc Error Data cannot be read for a specified
time due to scratches or dirt on disc
surface or insertion of music CD.
Inspect disc and replace if neces-
sary. (Visually check disc surface
and wipe it with soft cloth.) 42 58
(Navigation ECU)
Vehicle speed
sensor Signal
ErrorInput error of vehicle speed sensor
signal is detected. (When no vehicle
speed sensor signal has been input
for a specified time.)
Check the vehicle speed signal in
the diagnosis system mode.

Inspect wire harness for vehicle
speed signal.

If wire harness is normal, replace
navigation ECU. 43 58
(Navigation ECU)
Player Error Malfunction of player continues for a
specified length of time.
Check if disc can be inserted/tak-
en out or not. If not , replace naviga-
tion ECU.

When the same code is detected
in recheck after deleting the DTC
memory. 44 58
(Navigation ECU)
GPS Receiver
ErrorOperation error of GPS receiver is
detected.
At an outdoor site with a clear
view, operate to display the GPS in-
formation screen of the diagnosis
system. If GPS time stamp is not
properly displayed after 15 min. or
more, replace navigation ECU. 11 58
(GPS receiver)
GPS Antenna
ErrorOperation condition of GPS anten-
na cable is detected. (Open circuit,
connection failure of connectors,
etc.)
Check if the GPS antenna is cor-
rectly connected or positioned or
not. After replacing the antenna, if
the error remains, replace the navi-
gation ECU. 40 58
(GPS receiver)
Power Supply
Error of GPS
AntennaAbnormal voltage of GPS antenna
cable or short circuit is detected.
Inspect GPS antenna and replace
if necessary. (When no continuity is
identified between connector's core
and sealed part, GPS antenna is
normal.)

If GPS antenna is normal, replace
navigation ECU. 41 58
(GPS receiver)
Player Temp.
Too HighReadout cannot be done because
temperature around player's pickup
(reading part) is too high.With IG switch OFF, leave vehicle in
cool shaded place for a while and
recheck. After deleting the DTC
memory, If same code detected, re-
place navigation ECU. 45 58
(Navigation ECU)
*2: Even if no failure is detected, it may be stored depending on the battery condition or voltage for starting an engine.
*3: It is stored when 180 sec. has passed after the power supply connector is pulled out after engine start.
*4: It may be stored when the engine key is turned again 1 min. after engine start.
*5: It may be stored when the engine key is turned again after engine start.
*6: When 210 sec. has passed after pulling out the power supply connector of the master component with the ignition
switch in ACC or ON, this code is stored.
± DIAGNOSTICSNAVIGATION SYSTEM
DI±817
2001 PRIUS (RM778U)

Absence of
Master D6 01
(Communication
Control)Component in which this code is re-
corded has been disconnected
from system with ignition in ACC or
ON. Or, when this code was re-
corded, multi±display assembly
was disconnected.
Check harness for power supply
system of multi display.

Check harness for communica-
tion system of multi display.

Check harness for power supply
system of navigation ECU.

Check harness for communica-
tion system of navigation ECU.
Connection
Check Error D7 01 *6
(Communication
Control)Component in which this code is re-
corded has been disconnected
from system after engine start.
Or, when this code was recorded,
multi±display assembly was dis-
connected.
D6
Check harness for power supply
system of multi display.

Check harness for communica-
tion system of multi display.

Check harness for power supply
system of navigation ECU.

Check harness for communica-
tion system of navigation ECU.
Transmission
Error DC 01
(Communication
Control)Transmission to component shown
by auxiliary code has been failed.
(This code does not necessarily
mean actual failure.)If same auxiliary code is recorded in
other component(s), check harness
for power supply and communica-
tion system of components shown
sub code.
Master Reset
(Momentary
Interruption) DD 01
(Communication
Control)
Check harness for power supply
system of multi±display assembly.

Check harness for communica-
tion system of multi±display assem-
bly.

If error occurs frequently, replace
multi±display assembly.
Registration
Completion
Instruction
Error E0 01
(Communication
Control)ºRegistration Completion Instruc-
tionº command from multi display
cannot be received.Since this DTC is provided for engi-
neering, it may be detected when
no actual failure exists.
ON/OFF
Instruction
Parameter
Error E2 01
(Communication
Control)Error is detected in ON/OFF control
command from multi±display as-
sembly.Replace multi±display assembly.
Registration
Request
Transmission E3 01
(Communication
Control)Since this DTC is provided for engi-
neering, it may be detected when
no actual failure exists.
Registration Request command
is output from slave component.

By reception of connection check
Instruction, Registration Request
command is output from sub±mas-
ter component.After engine is started, multi±dis-
play assembly was disconnected
from system.
Master Error DF 01
(Communication
Control)Due to defective condition of com-
ponent with a display, master func-
tion is switched to audio equip-
ment . Error occurs in communica-
tion between sub±master (audio)
and master component.
Check harness for power supply
of multi±display assembly.

Check harness for communica-
tion system of multi±display assem-
bly.

Check harness for communica-
tion system between multi±display
assembly and sub±master compo-
nent.
Plural Frame
Abort E4 01
(Communication
Control)
Since this DTC is provided for en-
gineering purpose, it may be de-
tected when no actual failure exists. Plural frame transmission is
aborted.
*6: When 210 sec. has passed after pulling out the power supply connector of the master component with the ignition
switch in ACC or ON, this code is stored. DI±818
± DIAGNOSTICSNAVIGATION SYSTEM
2001 PRIUS (RM778U)