2001 TOYOTA PRIUS stop start

± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
DI±341
2001 PRIUS (RM778U) 4/27/01
DTC P3011±P3029 Battery Block # Malfunction
CIRCUIT DESCRIPTION
Internal resistance of each battery module is measured, detecting battery deterioration for each block, 1 to
19. Nineteen blocks of battery modules are arranged in the order of 1 to 19 from the ECU side.
DTC No.DTC Detecting ConditionTrouble Area
P3011±P3029Battery internal resistance is abnormal.
Battery ECU

Battery pack
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P3011±P3029) being outputs?
YES Go to relevant DTC chart.
NO
2 Check that the block voltage during charging/ discharging.
PREPARATION:
(a) To ensure safety, conduct this test in a wide, clear level area which provides good traction.
(b) Turn ON the ºREADYº light.
(c) Warm up the engine and turn off the A/C switch.
(d) Fully apply the parking brake and chock the 4 wheels.
(e) Connect a TOYOTA hand±held tester to DLC3 and select HV BATTERY and then CURRENT DATA.
(f) Show voltage of the block corresponding to the DTC and other block (any block except the above±
mentioned block).
CHECK:
(a) Keep your left foot pressed firmly on the brake pedal and shift into the R position.
(b) Confirm the engine stopped in the R position. Step on the accelerator pedal until the engine starts,
stepping on the brake pedal firmly.
(c) Release the accelerator pedal when the engine starts. At the same time, monitor the change of the
voltage before engine starting (during discharging) and after engine starting (during charging).
DI82C±01

A16881
Voltage
Other block voltage
Voltage of the block
corresponding to the DTC
Discharging (engine stops) Charging (engine starts)A: 0.3 V or more A
B: 0.3 V or more B
Time
DI±342
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
2001 PRIUS (RM778U)
OK:
Before or after switch±over from discharging to charging, the relationship of the voltage size
are reversed and the difference of the voltage is 0.3 V ore more.
OK Go to step 5.
NG
3 Check that the HV battery blocks voltage swings at stall test.
PREPARATION:
(a) To ensure safety, conduct this test in a wide, clear level area which provides good traction.
(b) Turn ON the ºReadyº light.
(c) Warm up the engine and turn off the A/C switch.
(d) Fully apply the parking brake and chock the 4 wheels.
(e) Connect a TOYOTA hand±held tester to DLC3 and select HV BATTERY and then CURRENT DATA
to show ºBAT BLOCK MIN Vº and ºBAT BLOCK MAX Vº on the TOYOTA hand±held tester.
CHECK:
(a) Keep your left foot pressed firmly on the brake pedal and shift into the R position.
(b) Stepping on the brake pedal, release the accelerator pedal during the engine moving and step on the
accelerator pedal during the engine stopping.
(c) Continue STEP (b) for more than 20 min. and monitor the swing and the difference of the voltage be-
tween the data MAX V and MIN V.

DI7XP±01
± DIAGNOSTICSCOMBINATION METER SYSTEM
DI±669
2001 PRIUS (RM778U)
PRE±CHECK
1. BEFORE CHECK
Since a trouble symptom may result from multiple causes, check not only the part where a user complains
of but also the following items in order to be sure no other trouble is identified.

Fuse related parts

Wire harness related parts

Valve related parts
NOTICE:

Setting the ignition switch to START temporarily stops all meter operation, however, this is not
an error.

When replacing the combination meter ECU, carefully avoid any contact with the IC.

Removing a battery terminal during engine operation may cause a reversed current and lead
to malfunction.

When disconnecting any connector or terminal, be sure to disconnect the battery terminal.

± 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)

I18171
(+) (±)WP ON
Z18060
15 2
3
123 5
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±937
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check voltage between terminal WP of A/C amplifier and body ground.
PREPARATION:
(a) Remove the center cluster module control with connec-
tors still connected.
(b) Start engine.
(c) Operate blower motor.
CHECK:
Measure voltage between terminal WP of A/C amplifier and
body ground when each condition as shown in the chart.
OK:
conditionVoltage
Engine running10 ± 14 V
Engine stopBelow 1.0 V
OK Proceed to next circuit inspection shown on
problem symptoms table (See page DI±874).
NG
2 Check A/C water pump relay.
PREPARATION:
Remove the A/C water pump relay from engine room R/B 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 magnetic clutch relay.
OK