Toyota Prius: Battery Ecu (for Phev Model)

• Removal

Removal

REMOVAL

CAUTION / NOTICE / HINT

The necessary procedures (adjustment, calibration, initialization or registration) that must be performed after parts are removed and installed, or replaced during battery ECU assembly removal/installation are shown below.

Necessary Procedures After Parts Removed/Installed/Replaced

Replaced Part or Performed Procedure	Necessary Procedure	Effect/Inoperative Function when Necessary Procedure not Performed	Link
Replacement of battery ECU assembly	Current sensor offset learning	HV battery status information cannot be updated

HINT:

When the cable is disconnected / reconnected to the auxiliary battery terminal, systems temporarily stop operating. However, each system has a function that completes learning the first time the system is used.

Items for which learning is completed by driving the Toyota Prius vehicle

Effect/Inoperative Function when Necessary Procedure not Performed	Necessary Procedure	Link
Front Camera System	Drive the Toyota Prius vehicle straight ahead at 35 km/h (22 mph) or more for 5 seconds or more.

Items for which learning is completed by operating the vehicle normally

Effect/Inoperative Function when Necessary Procedure not Performed	Necessary Procedure	Link
*1: w/o Power Back Door System *2: w/ Power Back Door System
Power Door Lock Control System*1 Back door opener	Perform door unlock operation with door control switch or electrical key transmitter sub-assembly switch.
Power Back Door System*2	Reset back door close position
Air Conditioning System	After the ignition switch is turned to ON, the servo motor and expansion valve standard position is recognized.	-

CAUTION / NOTICE / HINT

COMPONENTS (REMOVAL)

Procedure		Part Name Code
1	WHEN REPLACING BATTERY ECU ASSEMBLY	-		-	-
2	HV SUPPLY BATTERY ASSEMBLY	G9510	-	-	-
3	NO. 1 TRACTION BATTERY COVER	-		-	-
6	BATTERY ECU ASSEMBLY	89890A		-	-

*1	NO. 1 HV BATTERY SEAL	-	-
●	Non-reusable part	-	-

PROCEDURE

1. WHEN REPLACING BATTERY ECU ASSEMBLY

NOTICE: Do not replace the battery ECU assembly and ECM at the same time as the HV battery learning values will be lost. However, if it is necessary to replace both ECUs at the same time, replace them by following the procedure below. Do not replace the battery ECU assembly or ECM with a used one from another Toyota Prius vehicle.

HV battery learning values are stored in the battery ECU assembly and ECM and are used to detect malfunctions and illuminate the hybrid battery indicator light in the combination meter assembly. When either of these ECUs is replaced, the new ECU receives the HV battery learning values from the other ECU and stores them.

(a) Procedure when replacing both battery ECU assembly and ECM:

(1) Disconnect the cable from the negative (-) auxiliary battery terminal.

(2) Replace either ECU.

(3) Connect the cable to the negative (-) auxiliary battery terminal.

(4) Turn the ignition switch to ON (READY) and wait for 5 minutes or more.

(5) Turn the ignition switch off and wait for 1 minute or more.

(6) Disconnect the cable from the negative (-) auxiliary battery terminal.

(7) Replace the other ECU.

(8) Connect the cable to the negative (-) auxiliary battery terminal.

(9) Check that the ignition switch can be turned on (READY).

HINT:

If the battery ECU assembly and ECM are replaced at the same time without following the above procedure, replace either of the ECUs with its original one and then replace it again by following the above procedure. If the correct procedure is not followed, perform the procedure again from the beginning.

2. REMOVE HV SUPPLY BATTERY ASSEMBLY

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3. REMOVE NO. 1 TRACTION BATTERY COVER

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4. REMOVE BATTERY ECU ASSEMBLY

CAUTION: Be sure to wear insulated gloves and protective goggles. NOTICE: If the battery ECU assembly has been struck or dropped, replace it.