Page 909 of 1943
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
DI±319
2001 PRIUS (RM778U) BATT TEMP #
Battery temperature
ECU CODEECU code
IG OFF HOURAverage time of IG OFF
IG ON HOURAverage time of IG ON
ET OFF CHG HREstimation of time to finish OFF BOARD
DTCThe number of stored DTC
Page 910 of 1943
DI824±01
A14078
Engine Room J/B
Fusible Link Block No. 1
Fusible Link Block No. 2
BatteryBattery ECU
1
1B
B
MAINB±GG±YJ2 J/C
11
1F
1
F121
F135
IH11
B17 HV
1
F18G±Y G±Y
BBAM
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
DI±323
2001 PRIUS (RM778U)
CIRCUIT INSPECTION
DTC P1600 Back Up Power Source Circuit Malfunction
CIRCUIT DESCRIPTION
Battery positive voltage is supplied to terminal AM of the Battery ECU even when the ignition switch is OFF
to read the DTC memory and freeze frame data adaptive control value memory, etc.
DTC No.DTC Detecting ConditionTrouble Area
P1600Open in back up power source circuitOpen in back up power source circuit
Battery ECU
HINT:
If DTC P1600 appears, the Battery ECU does not store any other DTC.
WIRING DIAGRAM
Page 911 of 1943

A14081
AM
A14082
Engine Room J/B
HV Fuse
DI±324
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
HINT:
Read freeze frame data using a TOYOTA hand±held tester or OBD II scan tool. Because freeze frame data
records the battery condition when the malfunction is detected. When troubleshooting, this is useful for
knowing the battery condition.
1 Check voltage between terminal AM of Battery ECU connector and body ground.
PREPARATION:
Remove the luggage trim.
CHECK:
Measure the voltage between terminal AM of the Battery ECU
connector and body ground.
OK:
Voltage: 9 ± 14 V
OK Check and replace Battery ECU (See page
IN±41).
NG
2 Check HV fuse of engine room J/B.
PREPARATION:
Remove the HV fuse from the engine room J/B.
CHECK:
Check the continuity of the HV fuse.
OK:
Continuity
NG Check for short in all harness and components
connected to HV fuse.
OK
Check and repair harness or connector be-
tween battery and HV fuse, and HV fuse and
Battery ECU (See page IN±41).
Page 912 of 1943
A15624
HV ECUBattery ECU
HTD+
HTD±W
B 2
H13
20
H13W
B 1
IF2
2
IF26
B17
7
B17 DI±326
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
2001 PRIUS (RM778U)
DTC P3002 HV ECU Communication Malfunction
CIRCUIT DESCRIPTION
The battery ECU receives information of the AC ECU, system main relay connection signals, etc. sent from
the HV ECU, and stores DTC when an error is detected in the receives information.
DTC No.DTC Detecting ConditionTrouble Area
P3002No serial signals transmitted from HV ECUCommunication bus line
HV ECU
HINT:
Check DTC of other ECUs and see whether any communication error of the HV ECU is stored or not.
If HV communication errors are stored in then one ECU, replace the HV ECU.
WIRING DIAGRAM
DI826±01
Page 913 of 1943
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
DI±327
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open and short in wire harness between HV ECU and battery ECU.
PREPARATION:
Disconnect the connector from the battery ECU and the HV ECU
CHECK:
Check that the communication bus line is not short or open.
Terminals for checking open and short:
HV ECU TerminalsBattery ECU Terminals
H13 ± 2B17 ± 6
H13 ± 20B17 ± 7
OK:
No open or short.
NG Repair or replace the wire harness.
OK
2 Stop operation of all optional electric products for vehicle and check if same
DTC is stored.
NO Stop using product that causes noise.
YES
Replace the HV ECU.
Page 914 of 1943
A13558
Power Cable
to System Main Relay,
InverterBattery ECU
Service Plug Assembly
High Voltage Fuse
Service Plug
Power CableBattery Block No. 10L±W
L
76
to System Main Relay,
Inverter
DI±328
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
2001 PRIUS (RM778U)
DTC P3005 High Voltage Fuse Snapped
CIRCUIT DESCRIPTION
A fuse is set in the service plug to protect high±voltage system parts.
DTC No.DTC Detecting ConditionTrouble Area
P3005Although interlock switch is connected, voltage of battery block
No. 10 is less than specified.High voltage fuse
Power cable
WIRING DIAGRAM
DI827±01
Page 915 of 1943
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
DI±329
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P3005) and other ECU being output?
YES Go to relevant DTC chart.
NO
2 Check continuity of high voltage fuse in the service plug assembly and check
condition of service plug terminal (Loosened, poor contact, etc.).
OK Repair or replace the power cable.
NG
Repair or replace the service plug or the high
voltage fuse in the service plug assembly.
Page 916 of 1943
DI±332
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
2001 PRIUS (RM778U) 4/27/01
DTC P3009 Leak Detected
CIRCUIT DESCRIPTION
Electric leak from the high±voltage system, which may seriously harm the human body, is detected by this
code.
DTC No.DTC Detecting ConditionTrouble Area
P3009Electric leak from high±voltage system
(Insulating resistance of power cable is 100 kW or less.)
Power cable
HV transaxle
Converter & inverter assembly
Battery cover
System main relay
Battery temperature sensor
Battery ECU
Battery carrier catch bracket
Main battery cable
Service plug assembly
HV battery assembly
INSPECTION PROCEDURE
1 Is DTC P3125 of HV ECU being output?
YES Go to relevant DTC chart.
NO
2 Are there any other codes (Desides DTC P3009) being output?
YES Go to relevant DTC chart.
NO
DI82A±01