2001 TOYOTA PRIUS battery

S04947S04946
A14712
12
35
12
35
Ohmmeter
Battery Continuity
Ohmmeter
Ohmmeter
ContinuityNo Continuity
DI±248
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check IGCT relay.
PREPARATION:
Remove the IGCT relay from the engine room R/B No. 3.
CHECK:
(a) Using an ohmmeter, check that there is continuity be-
tween terminals 1 and 2.
(b) Check that there is no continuity between terminals 3 and
5.
(c) Apply battery voltage across terminals 1 and 2. Using an
ohmmeter, check that there is continuity between termi-
nals 3 and 5.
OK:
(a) Continuity
(b) No continuity
(c) Continuity
NG Replace IGCT relay.
OK
Check for +B short in wire harness between HV ECU and IGCT relay (See page IN±41).
Repair or replace wire harness.
HINT:
The HV ECU MREL terminal has +B short if the battery voltage is always applied to the HV ECU +B1 or MREL
terminal with the ignition OFF.

DI±250
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open, short and +B short in wire harness between HV ECU terminals
(Cont1, Cont2, Cont3) and system main relay terminals (See page IN±41).
HINT:
Confirm that there is no open circuit in the wire harness. If the battery voltage is always applied to the HV
ECU Cont1, Cont2 and Cont3 terminals with the ignition ON (ºREADYº light OFF), the system main relay
has +B short.
NG Repair or replace wire harness.
OK
2 Is any of the information code 231, 232 or 233 recorded?
NO Replace HV ECU.
YES
Replace HV ECU and system main relay.

DI±252
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
DTC P3120 HV Transaxle Malfunction
CIRCUIT DESCRIPTION
The HV ECU checks the energy balance and detects abnormality if the magnetism of the motor or generator
greatly decreases.
HINT:

When using an OBD scan tool other than TOYOTA hand±held tester, check all the steps.

When using TOYOTA hand±held tester, confirm the information code and check it.
DTC P3120 ± Information code 234, 235, 236, 237
INF. Code.Detecting ConditionTrouble Area
234Small reduction of motor magnetism
HV transaxle (motor)
235Large reduction of motor magnetism

HV transaxle (motor)

System main relay
236Small reduction of generator magnetism
HV transaxle (generator)
237Large reduction of generator magnetism

HV transaxle (generator)

System main relay
INSPECTION PROCEDURE
1 Is DTC of HV battery ECU being output?
YES Check applicable DTC.
NO
2 Turn the ignition switch to ST(ON) and check if malfunction occurs again.
NO Replace system main relay.
YES
Replace HV transaxle motor or generator.
DI837±02

A14140
C4
ConverterHybrid Vehicle
Control ECU
NODD
4L ± O
NODD 4
H12 DI±266
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
DTC P3125 Converter & Inverter Assembly Malfunction
CIRCUIT DESCRIPTION
If driving the vehicle with the DCDC converter malfunctioning, the voltage of the auxiliary battery will drop,
which will make it impossible to keep driving the vehicle. Therefore, HV ECU checks the operation of the
DCDC converter and gives warning to the driver if malfunction is detected.
HINT:

When using an OBD scan tool other than TOYOTA hand±held tester, check all the steps.

When using TOYOTA hand±held tester, confirm the information code and check it.
DTC P3125 ± Information code 263, 264, 265
INF. Code.Detecting ConditionTrouble Area
263+B short in DCDC converter NODD wiring
264DCDC converter malfunction
Converter & inverter assembly

Wire harness265Open or GND short in DCDC converter NODD wiring
Wire harness
WIRING DIAGRAM
DI838±02

± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±267
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open, short and +B short in wire harness between HV ECU NODD ter-
minal and converter & inverter NODD terminal (See page IN±41).
HINT:
The converter has +B short if the battery voltage is always applied to the HV ECU NODD terminal with the
ignition ON.
NG Repair or replace wire harness.
OK
Replace converter & inverter assembly.

A14121
InverterHybrid Vehicle
Control ECU
VBY 5
I10
6
I9 M±GINVB20
H11
26
H11VB
MIVG DI±268
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
CIRCUIT DESCRIPTION
The HV ECU checks the inverter voltage and detects malfunction.
DTC P3125 ± Information code 266, 267, 268, 269, 270
INF. Code.Detecting ConditionTrouble Area
266Open or GND short in inverter voltage signal circuit
267+B short in inverter voltage signal circuit
268Inverter voltage signal is inconsistent with battery voltage
Converter & inverter assembly269Inverter voltage sensor malfunction
Converter & inverter assembly

Wire harness
270
Abnormality of line connection of inverter voltage signal
circuit (when there is a history that the state of malfunction
continued during inverter fail safe mode)

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.

± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±301
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open, short and +B short in wire harness between HV ECU GSDN ter-
minal and converter & inverter assembly G±SDOWN terminals (See page
IN±41).
HINT:
Confirm that there is no open circuit in the wire harness. The generator gate shutdown signal circuit has +B
short if the battery voltage is always applied to the HV ECU GSDN terminal with the ignition ON.
NG Repair or replace wire harness.
OK
Replace converter & inverter assembly.