2001 TOYOTA PRIUS light

A14121
InverterHybrid Vehicle Control ECU
M±SINVG 7
I10
6
I9 M±GINVB21
MSIV
MIVG 26
H11H11
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±275
2001 PRIUS (RM778U)
CIRCUIT DESCRIPTION
The HV ECU checks the line connection of the motor inverter stop signal circuit and enters the fail safe mode
(limited output driving) if malfunction is detected.
DTC P3125 ± Information code 278, 280
INF. Code.Detecting ConditionTrouble Area
278+B short in motor inverter stop signal circuit
Converter & inverter assembly
280Open or GND short in motor inverter stop signal circuit

Converter & inverter assembly

Wire harness
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check for open, short and +B short in wire harness between HV ECU MSIV and
MIVG terminals and converter & inverter assembly M±SINV and M±GIVN termi-
nals (See page IN±41).
HINT:
The motor inverter stop signal circuit has +B short if the voltage between the HV ECU MSIV or MIGV terminal
and body ground is always more than 13 V with the ignition ON (ºREADYº light OFF).
NG Repair or replace wire harness.
OK
Replace converter & inverter assembly.

A14121
InverterHybrid Vehicle Control ECU
M±GINVB 6
I9
8
I10 M±FINVB26
MFIV 14 H11
H11MIVG
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±277
2001 PRIUS (RM778U)
CIRCUIT DESCRIPTION
The HV ECU checks the line connection of the motor inverter fail signal circuit and detects malfunction.
DTC P3125 ± Information code 283, 285
INF. Code.Detecting ConditionTrouble Area
283+B short in motor inverter fail signal circuit
Converter & inverter assembly
285Open or GND short in motor inverter fail signal circuit

Converter & inverter assembly

Wire harness
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check for open, short and +B short in wire harness between HV ECU MFIV and
MIVG terminals and converter & inverter assembly M±FINV and M±GINV termi-
nals (See page IN±41).
HINT:
The motor inverter fail signal circuit has +B short if the voltage between the HV ECU MIVG or MFIV terminal
and body ground is always more than 13 V with the ignition ON (ºREADYº light OFF).
NG Repair or replace wire harness.
OK
Replace converter & inverter assembly.

DI±292
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open, short and +B short in wire harness between HV ECU GSIV and
GIVG terminals and converter & inverter assembly G±SINV and G±GINV termi-
nals (See page IN±41).
HINT:
The generator inverter stop signal circuit has +B short if the voltage between the HV ECU GSIV or GIVG
terminal and body ground is always more than 13 V with the ignition ON (ºREADYº light OFF).
NG Repair or replace wire harness.
OK
Replace converter & inverter assembly.
CIRCUIT DESCRIPTION
DTC P3125 ± Information code 317, 319, 320
INF. Code.Detecting ConditionTrouble Area
317Over voltage of inverter
319Voltage drop of inverter power source
Converter & inverter assembly
320Inverter circuit broken
Converter & inverter assembly
INSPECTION PROCEDURE
If the information code 317 or 319 is output, check if other information codes are recorded. If they are re-
corded, check and repair those codes first.
If the information code 317 or 319 alone is recorded, replace the converter & inverter assembly.
If the information code 320 is output, replace the converter & inverter assembly.

DI±294
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open, short and +B short in wire harness between HV ECU GFIV and
GIVG terminals and converter & inverter assembly G±FINV and G±GINV terminals
(See page IN±41).
HINT:
The generator inverter fail signal circuit has +B short if the voltage between the HV ECU GFIV or GIVG termi-
nal and body ground is always more than 13 V with the ignition ON (ºREADYº light OFF).
NG Repair or replace wire harness.
OK
Replace converter & inverter assembly.
CIRCUIT DESCRIPTION
DTC P3125 ± Information code 322, 324, 325
INF. Code.Detecting ConditionTrouble Area
322Inverter overheating
324Inverter circuit broken
Converter & inverter assembly
325Inverter internal short
Converter & inverter assembly
INSPECTION PROCEDURE
If the information code 322 or 325 is output, check if other information codes are recorded. If they are re-
corded, check and repair those codes first.
If the information code 322 or 325 alone is recorded, replace the converter & inverter assembly.
If the information code 324 is output, replace the converter & inverter assembly.

DI2VS±03
Prius Problem Check Sheet
Vehicle
Specifications
Please fill in the blanks within bold frame.Name of DealerPerson in Charge at
HeadquartersPerson in Charge
at Dealer
Model CodeOffice
Vehicle Delivery Date
Frame No.
Unit No. etc.
Option . . . :
( ) Navigation (equipped by ( ) MOP ( ) dealer) ( ) Cold climate specification
( ) others( )Problem Occurrence Date
Service Entry Date NHW11±
. .
. .Odometer Reading
Registration datekm
. .
Contents of complaint (Status when and before/after occurring in
the order of events as correct as possible)Characteristics of Customer
Gender
Age
Occupation
Vehicle used before
Main use area
Frequency in use
Others times/day or
week or month
Status of engineOthers
Interview Results
( ) Male ( ) Female
suburbs ( ) %
Others ( ) ( ) %
city area ( ) %
mountain area ( ) %
Driving ConditionRoad Condition
Vehicle Condition
Vehicle Speed
km/h
mph
( ) when starting
( ) when according
( ) When
normal driving
( ) when
decelerating
( ) when braking
( ) when shopping
( ) when parking
( ) when turning
( ) when
ABS actuating
( ) others
( )( ) flat road
( ) up hill ( ) down
hill incline of
° /%
distance
km
mph
( ) dry paved road
( ) wet paved road
( ) rough paved road
( ) unpaved road
( ) snowy/frozen
road
( ) bump/curb
( ) others
( )( ) when starting
( ) right after
starting
( ) until min.
after starting
( ) until min.
after starting
of driving
( ) when shopping
system
( ) while shopping
engine
( ) when starting
engine
( ) when revolving
engineHV Battery
indication
( ) 4/4 ( ) 3/4
( ) 2/4 ( ) 1/4
( ) unidentified
Shift position
(indication)
( ) P ( ) R ( ) N
( ) D ( ) B
( ) when operating
"Weather:
A/C status
( ) no indication
( ) unidentified
( ) A/C ( ) FULL
( ) OFF
( ) unidentifiedWarning light
(MIL)
( ) ON ( ) OFF
( ) PS
( ) main battery
( ) HV!
( ) engine
( ) charge
( ) output
control
( ) brake
( ) ABS
( ) others
( )
Temperature:
°C
Brake operation
( ) brake slowly
( ) Brake suddenly
( ) use two pedals
system
Frequency in
occurrence
( ) always
( ) sometimes
( ) only once
miles
°F
Fuel level
( ) segments
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
DI±313
2001 PRIUS (RM778U)
CUSTOMER PROBLEM ANALYSIS CHECK

Verification Results of Warning Light
Engine
HV
INF. code
HV battery
Vehicle Verification Results
( ) ON ( ) OFF
( ) engine ( ) HV
( ) HV battery
( ) output control warning light
( ) brake ( ) ABS ( ) charge ( ) PS
( ) others
( )Verification Results of Diagnostic Code
Brake
PS
Vehicle Inspection Results (Verification items, reason to identify/presume the cause parts, etc.)
Replacement Parts
problem parts: No/Yes (Sending date: . . )Duplication Status
( ) always
( ) sometimes
( ) no reproduction
Confirmation Results
After Repair
( ) Normal
( ) reproduction
( ) others ( )
DI±314
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
2001 PRIUS (RM778U)

B04757
DI820±01
A14089A14090
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
DI±315
2001 PRIUS (RM778U)
PRE±CHECK
1. PRECAUTION
(a) To distinguish a trouble and replace a defective part, take
necessary preventive measures against an electric shock
(See page IN±4).
(b) Some portions of the wiring harness in the THS vehicle
have the circuits, to which a high voltage is applied. To
prevent an electrical shock, be sure to observe the follow-
ing:
(1) Wear insulated gloves during inspection.
(2) Remove a service plug and do not start any repair
operation before 5 minutes have passed, then con-
firm that the voltage at the output terminals has
dropped down to 12 V or less.
(3) Use insulated tools during inspection.
(4) When disengaging wiring connectors, hold the con-
nector bodies to avoid pulling the wires. When en-
gaging wiring connectors, be sure to engage them
securely.
(c) Do not leave tools or parts (bolts, nuts, etc.) inside the
cabin.
(d) Do not carry metallic objects such as mechanical pencils
or scales.
2. DIAGNOSIS SYSTEM
(a) Description

The HV Battery ECU has a self±diagnosis system
by which malfunction in the computer itself or in Hy-
brid System is detected and the master warning
light in the combination meter and the Hybrid sys-
tem warning light in the multi±information display
lights up.

A14089
B12009
F12396
DLC3
TOYOTA hand±held tester
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
DI±317
2001 PRIUS (RM778U)
(2) Inspect the auxiliary battery, fuses, fusible links, wir-
ing harness, connectors and ground.
(b) Check the master warning light.
(1) Turn the ignition switch ON and confirm that the
master warning light comes on.
HINT:
If the master warning light does not come on, suspect a burnt
fuse, burnt bulb, or open in wiring harness.
(2) When the ºREADYº light is ON, the master warning
light should go off.
If the lamp remains on, the diagnosis system has detected a
malfunction or abnormality in the system.
(c) Check the DTC.
(1) Prepare a TOYOTA hand±held tester.
(2) Connect the TOYOTA hand±held tester to the
DLC3.
(3) Turn the ignition switch ON and push the TOYOTA
hand±held tester main switch ON.
(4) Use the TOYOTA hand±held tester to check the
DTC and freeze frame data and note them down.
(For operating instructions, see the TOYOTA hand±
held tester operator's manual).
Since the HV battery ECU stores DTC and freeze
frame data, when troubleshooting, check all of the
DTC, write down the freeze fame data and perform
inspection according to the procedures of ºCircuit
Inspectionº.
Because the HV battery ECU is communicating with
the HV ECU, if any DTC is stored in the HV battery
ECU, check and record DTC stored in the HV ECU
(For tables for DTC, see page DI±177).
(5) See a related page to confirm details of the DTC.