Page 850 of 1943
± 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 problemHV transaxle motor
INSPECTION PROCEDURE
If the information code 248 or 250 is output, replace the HV transaxle motor.
Page 855 of 1943
A14121
Motor Generator No. 1Hybrid Vehicle
Control ECU
4
M2
9
M2B±R
GMT
GMTG G±W1
H10
8
H10 GMT
GMTG DI±264
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
CIRCUIT DESCRIPTION
The HV ECU checks the generator temperature and controls the load limitation in order to prevent the gener-
ator from overheating. Also, it detects the abnormality of the line connection of the generator temperature
sensor and the malfunction of the sensor itself.
DTC P3120 ± Information code 257, 259
INF. Code.Detecting ConditionTrouble Area
257GND short in generator temperature sensorHV transaxle
259Open or +B short in generator temperature sensor
HV transaxle
Wire harness
WIRING DIAGRAM
Page 856 of 1943
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±265
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open, short and +B short in wire harness between HV transaxle gener-
ator temperature sensor GMT and GMTG terminals and HV ECU GMT and GMTG
terminals (See page IN±41).
HINT:
Confirm that there is no open circuit in the wire harness. If the voltage of the HV ECU GMT terminal is always
more than 5V with the ignition ON, the generator temperature sensor circuit has +B short.
NG Repair or replace wire harness.
OK
Check for open in generator temperature sensor and then replace HV transaxle generator.
Check generator temperature sensor (See page HV±40).
CIRCUIT DESCRIPTION
DTC P3120 ± Information code 258, 260
INF. Code.Detecting ConditionTrouble Area
258Generator temperature sensor malfunctionHV t l ( t )260Generator temperature sensor performance problemHV transaxle (generator)
INSPECTION PROCEDURE
If the information code 258 or 260 is output, replace the HV transaxle generator.
Page 859 of 1943
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 voltageConverter & inverter assembly269Inverter voltage sensor malfunctionConverter & 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
Page 864 of 1943
A14121
InverterHybrid Vehicle Control ECU
M±SINVG 7
I10
6
I9 M±GINVB21
MSIV
MIVG 26
H11H11
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±273
2001 PRIUS (RM778U)
CIRCUIT DESCRIPTION
The HV ECU checks the inverter temperature and controls the load limitation in order to prevent the inverter
from overheating. Also, it detects the abnormality of the line connection of the inverter temperature sensor
and the malfunction of the sensor itself.
DTC P3125 ± Information code 274, 275, 276, 277
INF. Code.Detecting ConditionTrouble Area
274Open or +B short in motor inverter temperature sensor
275GND short in motor inverter temperature sensorConverter & inverter assembly
276Motor inverter temperature sensor malfunction
Converter & inverter assembly
Wire harness
277Motor inverter temperature sensor performance problem
WIRING DIAGRAM
Page 865 of 1943
DI±274
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open, short and +B short in wire harness between HV ECU MIT and
MIVG terminals and converter & inverter M±INVT, M±GINV terminals (See page
IN±41).
HINT:
Confirm that there is no open circuit in the wire harness. If the voltage between the HV ECU MIT or MIVG
terminal and body ground is always more than 5V with the ignition ON, the motor inverter temperature sensor
circuit has +B short.
NG Repair or replace wire harness.
OK
Check for open in motor inverter temperature sensor and then replace converter & inverter as-
sembly. Check motor inverter temperature sensor (See page HV±14).
Page 870 of 1943
A14123
InverterHybrid Vehicle Control ECU
M±GINVB
2
I10 M±IWAR B
W
G 4
I103
I101
I106
I9
M±IWB M±IVB M±IVAMIVG
MIWAMIWB MIVB MIVA 26
16
7
17
25
H11 H11 H11 H11 H11
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±279
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 288, 289, 290, 292, 294, 296, 297, 298, 300, 302,
INF. Code.Detecting ConditionTrouble Area
289Open in motor inverter current sensor (V phase sub sensor)
292Open in motor inverter current sensor (V phase main sen-
sor)
297Open in motor inverter current sensor (W phase sub sen-
sor)
300Open in motor inverter current sensor (W phase main sen-
sor)
288Motor inverter current sensor malfunction (V phase sub
sensor)
Ct&it bl
290Motor inverter current sensor malfunction (V phase main
sensor)Converter & inverter assembly
Wire harness
294Motor inverter current sensor V phase performance prob-
lem
296Motor inverter current sensor malfunction (W phase sub
sensor)
298Motor inverter current sensor malfunction (W phase main
sensor)
302Motor inverter current sensor W phase performance prob-
lem
WIRING DIAGRAM
Page 872 of 1943
A14123
InverterHybrid Vehicle Control ECU
M±GINVB
2
I10 M±IWAR B
W
G 4
I103
I101
I106
I9
M±IWB M±IVB M±IVAMIVG
MIWAMIWB MIVB MIVA 26
16
7
17
25
H11 H11 H11 H11 H11
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±281
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 291, 293, 295, 299, 301, 303
INF. Code.Detecting ConditionTrouble Area
291
293
295When there is a history that the state of malfunction contin-Converter & inverter assembly
299
When there is a history that the state of malfunction contin
ued during inverter fail safe mode.
Converter & inverter assembly
Wire harness
301
g
303
WIRING DIAGRAM
