2001 TOYOTA PRIUS Service Repair Manual

± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
DI±337
2001 PRIUS (RM778U)
9 Check insulating resistance of main battery cable.
PREPARATION:
(a) Under step 7 condition, turn the ignition switch OFF and disconnect the negative terminal of the auxilia-
ry battery.
(b) Remove the service plug.
(c) Remove the main battery cables. (Disconnect 4 terminals of a long and a short cables connected be-
tween the system main relay and the HV battery.)
CHECK:
Using a megger (500V), measure the insulating resistance between the main battery cable and body ground.
OK:
Insulating resistance: 10MW or more
NG Replace the main battery cable.
OK
10 Check insulating resistance of system main relay.
CHECK:
Using a megger (500V), measure the insulating resistance between each of 2 connected parts of the system
main relay to the power cables and body ground, and between each of 2 connected parts of the system main
relay to the main battery cables and body ground.
OK:
Insulating resistance: 10MW or more
NG Replace the system main relay.
OK

DI±338
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
2001 PRIUS (RM778U) 4/27/01
11 Check insulating resistance of service plug assembly.
PREPARATION:
Under step 9 condition, disconnect the cable terminal of the service plug assembly from the HV battery.
CHECK:
Using a megger (500V), measure the insulating resistance between 2 cable terminals and body ground.
OK:
Insulating resistance: 10MW or more
NG Replace the service plug assembly.
OK
12 Check insulating resistance of HV battery temperature sensor.
PREPARATION:
Under step 10 condition, disconnect the HV battery temperature sensor connector from the battery ECU.
CHECK:
Using a megger (500V), measure the insulating resistance between each terminal of the HV battery temper-
ature sensor and body ground.
OK:
Insulating resistance: 10MW or more
NG Replace the HV battery temperature sensor.
OK

± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
DI±339
2001 PRIUS (RM778U)
13 Is DTC P3009 of battery ECU being output?
PREPARATION:
(a) Under step 11 condition, disconnect the HV connector from the battery ECU.
(b) Connect the negative terminal of the auxiliary battery (with the service plug removed).
(c) Turn the ignition switch ON (not ST) and clear the DTC.
HINT:
When the ignition switch is turned ON, DTC P3140 is stored in the HV ECU. This happens because the ser-
vice plug is removed, so continue the operation.
CHECK:
Check that DTC P3009 is detected.
YES Replace the HV battery ECU.
NO
14 Check insulating resistance of wire harness for module voltage detection.
PREPARATION:
(a) Under step 12 condition, turn the ignition switch OFF and disconnect the negative terminal of the auxil-
iary battery.
(b) Remove the 36 nuts and the busbar module on the battery rear side.
CHECK:
Using a megger (500V), measure the insulating resistance between the connector terminal of the wire har-
ness for the removed module's voltage detection and body ground.
OK:
Insulating resistance: 10 MW or more
NG Replace the HV battery assembly.
OK
Replace the HV battery ECU.

± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
DI±341
2001 PRIUS (RM778U) 4/27/01
DTC P3011±P3029 Battery Block # Malfunction
CIRCUIT DESCRIPTION
Internal resistance of each battery module is measured, detecting battery deterioration for each block, 1 to
19. Nineteen blocks of battery modules are arranged in the order of 1 to 19 from the ECU side.
DTC No.DTC Detecting ConditionTrouble Area
P3011±P3029Battery internal resistance is abnormal.
Battery ECU

Battery pack
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P3011±P3029) being outputs?
YES Go to relevant DTC chart.
NO
2 Check that the block voltage during charging/ discharging.
PREPARATION:
(a) To ensure safety, conduct this test in a wide, clear level area which provides good traction.
(b) Turn ON the ºREADYº light.
(c) Warm up the engine and turn off the A/C switch.
(d) Fully apply the parking brake and chock the 4 wheels.
(e) Connect a TOYOTA hand±held tester to DLC3 and select HV BATTERY and then CURRENT DATA.
(f) Show voltage of the block corresponding to the DTC and other block (any block except the above±
mentioned block).
CHECK:
(a) Keep your left foot pressed firmly on the brake pedal and shift into the R position.
(b) Confirm the engine stopped in the R position. Step on the accelerator pedal until the engine starts,
stepping on the brake pedal firmly.
(c) Release the accelerator pedal when the engine starts. At the same time, monitor the change of the
voltage before engine starting (during discharging) and after engine starting (during charging).
DI82C±01

A16881
Voltage
Other block voltage
Voltage of the block
corresponding to the DTC
Discharging (engine stops) Charging (engine starts)A: 0.3 V or more A
B: 0.3 V or more B
Time
DI±342
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
2001 PRIUS (RM778U)
OK:
Before or after switch±over from discharging to charging, the relationship of the voltage size
are reversed and the difference of the voltage is 0.3 V ore more.
OK Go to step 5.
NG
3 Check that the HV battery blocks voltage swings at stall test.
PREPARATION:
(a) To ensure safety, conduct this test in a wide, clear level area which provides good traction.
(b) Turn ON the ºReadyº light.
(c) Warm up the engine and turn off the A/C switch.
(d) Fully apply the parking brake and chock the 4 wheels.
(e) Connect a TOYOTA hand±held tester to DLC3 and select HV BATTERY and then CURRENT DATA
to show ºBAT BLOCK MIN Vº and ºBAT BLOCK MAX Vº on the TOYOTA hand±held tester.
CHECK:
(a) Keep your left foot pressed firmly on the brake pedal and shift into the R position.
(b) Stepping on the brake pedal, release the accelerator pedal during the engine moving and step on the
accelerator pedal during the engine stopping.
(c) Continue STEP (b) for more than 20 min. and monitor the swing and the difference of the voltage be-
tween the data MAX V and MIN V.

A16880
The difference of the voltage
between the date VMAX and VMIN
SwingVMAX data
The engine start Test startTime
Voltage
Swing
Swing
SwingVMIN data
± DIAGNOSTICSHV BATTERY CONTROL SYSTEM
DI±343
2001 PRIUS (RM778U) 4/27/01 OK:
Standard voltage swing: Less than 2 V
NG Replace the battery ECU (See page IN±41).
OK
4 Check the difference of the voltage between the data V MAX and V MIN.
Standard voltage difference: Less than 1.2 V
YES Replace the battery ECU. (See page IN±41).
NO
5 Replace the battery pack assembly, and initialize the battery ECU by performing
an active test.