Lexus TechDoc

DTC P0A94-587 DC / DC Converter Performance

for Preparation Click here

DESCRIPTION

For a description of the boost converter (Click here).
The MG ECU uses a voltage sensor (VL) that is built into the boost converter to detect the high voltage before it is boosted. The ECU also uses the battery smart unit to detect HV battery voltage (VB).

HINT:

Using the intelligent tester, check the Data List of HV battery voltage and current. If these values are not within the below range, there is a battery smart unit malfunction.

DTC No.	INF Code	DTC Detection Condition	Trouble Area
P0A94	587	Voltages from HV battery voltage (VB) sensor and boost converter voltage (VL) sensor deviate	Inverter with converter assembly Battery smart unit

INSPECTION PROCEDURE

1.CHECK DTC OUTPUT (HYBRID CONTROL)

Connect the intelligent tester to the DLC3.

Turn the power switch on (IG).

Enter the following menus: Powertrain / Hybrid Control / DTC.

Check if DTCs are output.

Result:

Result	Proceed to
DTC P0A94-587 only is output. Alternatively, P0A94- 587 and any DTCs other than P0AFC-129, P0A94-442 or P0A94-585 are output.	A
P0A94-587 and P0AFC-129 (HV battery voltage circuit malfunction) are output.	B
P0A94-587 and P0A94-442 (abnormal voltage execution value) are output.	C
P0A94-587 and P0A94-585 (boost converter voltage (VL) sensor performance problem) are output.	D

Turn the power switch off.

GO TO DTC CHART (P0AFC-129) (Click here)

REPLACE INVERTER WITH CONVERTER ASSEMBLY (Click here)

GO TO DTC CHART (P0A94-585) (Click here)

A

2.CLEAR DTC

Connect the intelligent tester to the DLC3.

Turn the power switch on (IG).

Enter the following menus: Powertrain / Hybrid Control / DTC.

Read and record the DTCs and freeze frame data.

Clear DTCs and freeze frame data.

Turn the power switch off.

NEXT

3.CHECK DTC OUTPUT (HYBRID CONTROL)

Connect the intelligent tester to the DLC3.

Turn the power switch on (READY). (*1)

Enter the following menus: Powertrain / Hybrid Control / Data List. (*2)

If both HV battery voltage (VB) and VL-Voltage before Boosting are less than 220 V, move the shift lever to D and depress both the accelerator pedal and brake pedal at the same time to raise them to 220 V or more. (*3)

Push the P position switch. (*4)

Set the air conditioning to MAX COOL and turn the headlights on. (*5)

Confirm that "Batt Pack Current Val" is more than 3 A. (*6)

Leave the vehicle for 15 seconds with the engine stopped during steps (*4) (*5) and (*6). (*7)

Enter the following menus: Powertrain / Hybrid Control / DTC. (*8)

Check if DTCs are output. (*9)

NOTICE:

If the low battery charge warning light comes on, push the P position switch and start the engine to charge the HV battery. After the engine stops, perform steps (*1) through (*9) again.

Result:

Result		Proceed to
No DTCs are output, or DTCs other than the following are output.		A
P0AFC-129 (HV battery voltage circuit malfunction) is output.		B
P0A94-585 (boost converter voltage (VL) sensor performance problem) is output.		C
P3000-388 (discharge inhibition) is output.		D
P3004-132 (high voltage power supply line problem) is output.		E

Turn the power switch off.

REPLACE BATTERY SMART UNIT (Click here)

REPLACE INVERTER WITH CONVERTER ASSEMBLY (Click here)

LEAVE VEHICLE WITH PARK (P) SELECTED, AND CHARGE HV BATTERY BY IDLING UNTIL IDLING STOPS (PERFORM STEPS (*1) THROUGH (*9))

REPLACE BATTERY SMART UNIT (Click here)

A

4.CHECK DTC OUTPUT (HYBRID CONTROL)

Turn the power switch on (READY).

Perform a road test that repeats full acceleration to 60 km/h (37 mph) and then braking to a complete stop three times. (*10)

Connect the intelligent tester to the DLC3.

Enter the following menus: Powertrain / Hybrid Control / DTC. (*11)

Check if DTCs are output. (*12)

Result:

Result		Proceed to
No DTCs are output, or DTCs other than the following are output.		A
P0AFC-129 (HV battery voltage circuit malfunction) is output.		B
P0A94-585 (boost converter voltage (VL)) sensor performance problem) is output.		C
P3000-388 (discharge inhibition) is output.		D
P3004-132 (high voltage power supply line problem) is output.		E

Turn the power switch off.

REPLACE BATTERY SMART UNIT (Click here)

REPLACE INVERTER WITH CONVERTER ASSEMBLY (Click here)

LEAVE VEHICLE WITH PARK (P) SELECTED, AND CHARGE HV BATTERY BY IDLING UNTIL IDLING STOPS (PERFORM STEPS (*10) THROUGH (*12))

REPLACE BATTERY SMART UNIT (Click here)

A

5.READ VALUE USING INTELLIGENT TESTER

Connect the intelligent tester to the DLC3.

Turn the power switch on (READY).

Enter the following menus: Powertrain / Hybrid Control / Data List.

Select HV battery voltage (VB), VL-Voltage before Boosting and VH-Voltage after Boosting in the Data List.

If both HV battery voltage (VB) and VL-Voltage before Boosting are less than 220 V, move the shift lever to D and depress both the accelerator pedal and brake pedal at the same time to raise them to 220 V or more.

Turn the engine off, push the P position switch, and read the Data List when the vehicle is stationary.

Result:

Result	Proceed to
Both of the following are not satisfied.	A
Both of the following are satisfied: Difference between "Power Resource VB" and "VH-Voltage after Boosting" is less than 5 V. Difference between VL-Voltage before Boosting and "VH-Voltage after Boosting" is more than 35 V.	B
Both of the following are satisfied: Difference between "VH-Voltage after Boosting" and "VL-Voltage before Boosting" is more than 5 V. Difference between "Power Resource VB" and "VH-Voltage after Boosting" is less than 15 V.	C

Turn the power switch off.

REPLACE INVERTER WITH CONVERTER ASSEMBLY (Click here)

REPLACE BATTERY SMART UNIT (Click here)

A

6.CHECK FREEZE FRAME DATA (HYBRID CONTROL)

Connect the intelligent tester to the DLC3.

Turn the power switch on (IG).

Enter the following menus: Powertrain / Hybrid Control / DTC.

Read the freeze frame data of DTC P0A94-587.

Result:

Result	Proceed to
Both of the following are satisfied or both of the following are not satisfied.	A
"Power Resource VB" is less than 160 V or more than 285 V.	B
"VL-Voltage before Boosting" is less than 160 V or more than 285 V.	C

Turn the power switch off.

REPLACE BATTERY SMART UNIT (Click here)

REPLACE INVERTER WITH CONVERTER ASSEMBLY (Click here)

A

7.CHECK FREEZE FRAME DATA (HYBRID CONTROL)

Connect the intelligent tester to the DLC3.

Turn the power switch on (IG).

Enter the following menus: Powertrain / Hybrid Control / DTC.

Read the freeze frame data of DTC P0A94-587.

HINT:

In the freeze frame data, read the HV battery voltage value and all of the battery block voltage values.

Result:

Result	Proceed to
Others (Freeze frame data is not stored).	A
Both of the following are satisfied: Sum of all "Battery Block" voltage is more than (HV battery voltage - 40 V) Sum of all "Battery Block" voltage is less than (HV battery voltage + 25 V)	B
Neither A nor B is satisfied.	C

Turn the power switch off.

REPLACE INVERTER WITH CONVERTER ASSEMBLY (Click here)

REPLACE BATTERY SMART UNIT (Click here)

A

8.READ VALUE USING INTELLIGENT TESTER

Connect the intelligent tester to the DLC3.

Turn the power switch on (READY).

Enter the following menus: Powertrain / Hybrid Control / Data List.

If both HV battery voltage (VB) and VL-Voltage before Boosting are less than 220 V, move the shift lever to D and depress both the accelerator pedal and brake pedal at the same time to raise them to 220 V or more.

Turn the engine off, push the P position switch, and read the Data List of all battery block and HV battery voltages, when the vehicle is stationary.

Result:

Result	Proceed to
Both of the following are satisfied: Sum of all "Battery Block" voltage is more than (HV battery voltage -40 V) Sum of all "Battery Block" voltage is less than (HV battery voltage +25 V)	A
The preceding condition is not satisfied.	B

Turn the power switch off.

REPLACE BATTERY SMART UNIT (Click here)

REPLACE INVERTER WITH CONVERTER ASSEMBLY (Click here)