2001 TOYOTA PRIUS Service Repair Manual

DI±282
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check continuity of wire harness between HV ECU and converter & inverter as-
sembly (See page IN±41).
OK:
Continuity: Less then 1 W
HV ECU TerminalsInverter Terminals
MIVAM±IVA
MIVBM±IVB
MIWAM±IWA
MIWBM±IWB
MIVGM±GINV
NG Repair or replace wire harness.
OK
2 Is there DTC P3100 being output?
YES Check applicable DTC.
NO
Replace converter & inverter assembly.

± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±283
2001 PRIUS (RM778U)
CIRCUIT DESCRIPTION
The HV ECU detects the malfunction of the motor inverter current sensor. It detects the malfunction of the
sensor system, not of the high voltage system.
DTC P3125 ± Information code 306, 307
INF. Code.Detecting ConditionTrouble Area
306Failure in monitoring motor torque performanceCt&it bl307Abnormal current value of motor
Converter & inverter assembly
INSPECTION PROCEDURE
If the information code 306 or 307 is output, check if other DTC or information codes are recorded. If they
are recorded, check and repair those codes first.
If the information code 306 or 307 alone is recorded, replace the converter & inverter assembly.
CIRCUIT DESCRIPTION
If the HV ECU detects the collision signal from the airbag or inverter, the HV ECU recognizes it as the destruc-
tion of the vehicle and then shuts down the high voltage system to ensure safety.
DTC P3125 ± Information code 308
INF. Code.Detecting ConditionTrouble Area
308Input of collision signal from airbag or inverter±
HINT:
When the vehicle collision occurs and the airbag is deployed, this information code will be recorded and the
high voltage system will be shut down.

A14120
InverterHybrid Vehicle
Control ECU
M±SDOWNY 4
I913
MSDN
H11 DI±284
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
CIRCUIT DESCRIPTION
The HV ECU checks the line connection of the motor gate shutdown signal circuit and detects malfunction.
DTC P3125 ± Information code 304, 305
INF. Code.Detecting ConditionTrouble Area
304+B short in motor gate shutdown signal circuit
Converter & inverter assembly
305Open or GND short in motor gate shutdown signal circuit

Converter & inverter assembly

Wire harness
WIRING DIAGRAM

± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±285
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open, short and +B short in wire harness between HV ECU MSDN ter-
minal and converter & inverter assembly M±SDOWN terminals (See page
IN±41).
HINT:
Confirm that there is no open circuit in the wire harness. The motor gate shutdown signal circuit has +B short
if the battery voltage is always applied to the HV ECU MSDN terminal with the ignition ON.
NG Repair or replace wire harness.
OK
Replace converter & inverter assembly.

A14124
InverterHybrid Vehicle
Control ECU
G 3
I112
I11 G±UUR3
H11
1
H11GWU
GUU GVU 2
H11 W I11
1 G±VU G±WU DI±286
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
CIRCUIT DESCRIPTION
The HV ECU detects faulty line connection inside the inverter.
DTC P3125 ± Information code 309
INF. Code.Detecting ConditionTrouble Area
309Open or short in generator inverter switching wiring (GUU,
GVU, GWU)
Wire harness

Converter & inverter assembly
WIRING DIAGRAM

± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±287
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open and short in wire harness between HV ECU terminals (GUU, GVU,
GWU) and inverter terminals.
NG Repair or replace wire harness.
OK
2 Is there DTC P3100 being output?
YES Check applicable DTC.
NO
Replace converter & inverter assembly.

A14120
InverterHybrid Vehicle
Control ECU
G±SDOWNY 4
I1112
GSDN
H11
DI±288
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
CIRCUIT DESCRIPTION
The HV ECU detects faulty line connection inside the inverter.
DTC P3125 ± Information code 311
INF. Code.Detecting ConditionTrouble Area
311Generator inverter malfunction
Converter & inverter assembly

Wire harness
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check for open and short in wire harness between HV ECU GSDN terminal and
converter & inverter S±DOWN terminal.
NG Repair or replace wire harness.
OK
Replace converter & inverter assembly.