2001 TOYOTA PRIUS Service Repair Manual

A14121
Motor Generator No. 2Hybrid Vehicle
Control ECU
MMTG
MMT3
M4
1
M4R±W
MMTG
MMT GR9
H10
2
H10 DI±258
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
CIRCUIT DESCRIPTION
The HV ECU checks the motor temperature and controls the load limitation in order to prevent the motor from
overheating. Also, it detects the abnormality of the line connection of the motor temperature sensor and mal-
function of the sensor itself.
DTC P3120 ± Information code 247, 249
INF. Code.Detecting ConditionTrouble Area
247GND short in motor temperature sensor
HV transaxle
249Open or +B short in motor temperature sensor

HV transaxle

Wire harness
WIRING DIAGRAM

± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±259
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check open, short and +B short in wire harness between HV transaxle motor
temperature sensor MMT and MMTG terminals and HV ECU MMT and MMTG ter-
minals (See page IN±41).
HINT:
Confirm that there is no open circuit in the wire harness. If the voltage of the HV ECU MMT terminal is always
more than 5V with the ignition ON, the motor temperature sensor circuit has +B short.
NG Repair or replace wire harness.
OK
Check for open in motor temperature sensor and then replace HV transaxle motor.
Check motor temperature sensor (See page HV±40).
CIRCUIT DESCRIPTION
DTC P3120 ± Information code 248, 250
INF. Code.Detecting ConditionTrouble Area
248Motor temperature sensor malfunctionHV t l t250Motor temperature sensor performance problem
HV transaxle motor
INSPECTION PROCEDURE
If the information code 248 or 250 is output, replace the HV transaxle motor.

A14122
Motor Generator No. 1Hybrid Vehicle
Control ECU
7
M2
2
M2
1
M2
6
M2
3
M2
8
M2G
RGSNG
GSN
GRF
GRFG
GCS
GCSG B
W
Y
BR11
H10
4
H10
10
H10
17
H10
5
H10
12
H10 GSNG
GSN
GRF
GRFG
GCS
GCSG DI±260
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
CIRCUIT DESCRIPTION
The HV ECU checks the generator resolver signal voltage and circuit impedance to detect malfunction.
DTC P3120 ± Information code 253, 255
INF. Code.Detecting ConditionTrouble Area
253Generator resolver inter±phase short
HV transaxle (generator)
255Open or short in generator resolver circuit

HV transaxle (generator)

Wire harness
WIRING DIAGRAM

± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±261
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open and short in wire harness between HV transaxle and HV ECU
(See page IN±41).
Terminals for checking open and short:
MG1 TerminalsHV ECU Terminals
GSNGGSNG
GSNGSN
GCSGCS
GCSGGCSG
GRFGRF
GRFGGRFG
NG Repair or replace wire harness.
OK
Check for open in generator resolver or inter±phase short and then replace HV transaxle genera-
tor.
Check generator resolver (See page HV±40).

A14122
Motor Generator No. 1Hybrid Vehicle
Control ECU
7
M2
2
M2
1
M2
6
M2
3
M2
8
M2G
RGSNG
GSN
GRF
GRFG
GCS
GCSG B
W
Y
BR11
H10
4
H10
10
H10
17
H10
5
H10
12
H10 GSNG
GSN
GRF
GRFG
GCS
GCSG DI±262
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
CIRCUIT DESCRIPTION
The HV ECU checks the generator resolver signal voltage and circuit impedance to detect malfunction.
DTC P3120 ± Information code 254, 256
INF. Code.Detecting ConditionTrouble Area
254
Generator resolver inter±phase short (when there is a histo-
ry that the state of malfunction continued during inverter fail
safe mode)

HV transaxle (generator)
256
Open or short in generator resolver circuit (when there is a
history that the state of malfunction continued during invert-
er fail safe mode)

HV transaxle (generator)

Wire harness
WIRING DIAGRAM