2001 TOYOTA PRIUS battery

A15650
Hybrid Vehicle
Control ECU
25
H14IB B±L
R±W Battery ECU
26
H14 GB B±L6
IB1
10
IB1 R±W 16
B17
17
B17 IB
GB
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±231
2001 PRIUS (RM778U)
CIRCUIT DESCRIPTION
The HV ECU checks the current value of the battery and detects malfunction.
DTC P3100 ± Information code 127, 128, 138
INF. Code.Detecting ConditionTrouble Area
127+B short in IB terminal circuit of HV ECU
128Open or short in IB terminal circuit of HV ECU
Wire harness
138When the difference between battery current of HV ECU
and current of battery is large.
Wire harness

HV ECU
WIRING DIAGRAM

DI±232
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Is DTC of battery ECU being output (See page DI±312)?
HINT:
In case of output of Information code 128, check whether V± wire harness of battery ECU DTC P3115 is open
or short at first. When there is no±abnormality, go to step 2.
Yes Check applicable DTC (See page DI±312).
NO
2 Check for open, short and +B short in wire harness between HV ECU IB and GB
terminals and battery ECU IB and GB terminals (See page IN±41).
HINT:
The HV ECU IB terminal has +B short if there is no open in wire harness and the voltage of the IB or GB
terminal is more than 5 V with the ignition ON.
NG Repair or replace wire harness.
OK
Replace HV ECU.

A14148
Hybrid Vehicle
Control ECU
Instrument Panel J/BI15
Ignition SW
Engine Room J/BFusible Link
Block No. 1ST2 R±W6
H13 2C2
W±R
2G2
W±R
1J9AM2
B
B±G
MAIN
Battery1B2
F121
F131
B±G
F181 Fusible Link
Block No. 2
ST2 AM27
8
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±233
2001 PRIUS (RM778U)
CIRCUIT DESCRIPTION
The HV ECU checks the ST signal and detects malfunction. If the ST signal has +B short, the ST will always
be ON. Therefore, even with the IG ON when starting the THS, the system will start. To prevent this from
happening, the HV ECU detects the malfunction of the ST signal.
DTC P3100 ± Information code 142
INF. Code.Detecting ConditionTrouble Area
142When ST signal of HV ECU is ON, with ignition switch
turned OFF.
Wire harness

HV ECU

Ignition switch
WIRING DIAGRAM

DI±234
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check ignition switch (See page BE±17).
NG Replace ignition switch (See page SR±11).
NO
2 Check for +B short in wire harness between ignition switch ST2 terminal and HV
ECU ST2 terminal (See page IN±41).
HINT:
The HV ECU ST circuit has +B short if battery voltage is supplied to the ST2 terminal.
NG Repair or replace wire harness.
OK
Replace HV ECU.

A14734
Hybrid Vehicle
Control ECU
19
H13
DTH+
DTH± R
G Battery ECU
18
H13 4
IF2
3
IF2 R
G 18
B17
19
B17 BEH+
BEH± DI±238
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
DTC P3105 Battery ECU Communication Circuit Mal-
function
CIRCUIT DESCRIPTION
The HV ECU monitors the communication signal from the battery ECU and if it cannot monitor it due to noise
or other reasons, judges as an error.
DTC P3105 ± Information code 206, 207, 208
INF. Code.Detecting ConditionTrouble Area
206
207When communication between battery ECU and HV ECU is
abnormal 1 sec after ignition is turned ON

Wire harness

Battery ECU208abnormal 1 sec. after ignition is turned ON
Battery ECU
WIRING DIAGRAM
DI830±02

± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±239
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open and short in wire harness between HV ECU terminals (DTH+,
DTH±) and battery ECU terminals (BEH+, BEH±) (See page IN±41).
NG Repair or replace wire harness.
OK
Replace battery ECU.

± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±243
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open, short and +B short in wire harness between HV ECU ABFS ter-
minals and airbag ECU GSW 2 terminal (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 ABFS terminal with the ignition ON, the airbag signal circuit has +B short.
NG Repair or replace wire harness.
OK
Replace airbag sensor assembly.

A14737
Hybrid Vehicle
Control ECU Engine Room R/B No. 2
Fusible Link
Block No. 1
Battery+B1
MREL 4
H14
1FG±Y
W±G
O 2
7
H12 W±G12
IA1
2 2
2
213 5
Engine
Room J/B 11
HV
F12B±GMAIN 1B 1
B
F13Fusible Link
Block No. 2
1
F18 A
J7
J/C
W±B
IE
EC W±B W±B
AJ1
J/C
AA IGCT Relay
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±247
2001 PRIUS (RM778U)
DTC P3110 IGCT Relay Malfunction
CIRCUIT DESCRIPTION
The HV ECU checks the IGCT relay and detects malfunction.
DTC P3110 ± Information code 223
INF. Code.Detecting ConditionTrouble Area
223
When IGCT relay is always closed.
Wire harness

IGCT relay
WIRING DIAGRAM
DI835±02