U029A

HYBRID BATTERY CONTROL: HYBRID BATTERY SYSTEM: U029A-123: Lost Communication with Hybrid Battery Pack Sensor Module
U029A-123 - Lost Communication with Hybrid Battery Pack Sensor Module

DESCRIPTION

The battery smart unit detects the HV battery conditions (voltage, current, and temperature) and the battery cooling fan voltage, and sends the detected information to the hybrid vehicle control ECU.





WIRING DIAGRAM





INSPECTION PROCEDURE

CAUTION:
* Before inspecting the high-voltage system, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
* After disconnecting the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.
HINT
Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

PROCEDURE

1. CHECK WAVEFORM

CAUTION:
Be sure to wear insulated gloves.

(a) Connect an oscilloscope to the hybrid vehicle control ECU and battery smart unit terminals specified in the table below and measure the waveform.









OK:

The waveform appears as shown in the illustration.

NG -- CHECK AUXILIARY BATTERY

OK -- REPLACE HYBRID VEHICLE CONTROL ECU Removal

2. CHECK AUXILIARY BATTERY

(a) Turn the power switch off.

(b) Measure the voltage between the terminals of the auxiliary battery.

Standard Voltage:





NG -- CHARGE OR REPLACE AUXILIARY BATTERY
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (IGCT VOLTAGE)

(a) Turn the power switch on (IG).

(b) Measure the voltage according to the value(s) in the table below.





Standard Voltage:





HINT
* For the removal and installation procedures related to the No. 1 battery pack wire inspection, Removal.
* Perform this inspection with the No. 1 battery pack wire connected.

NG -- CHECK FUSE (IGCT3)
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (NO. 1 BATTERY PACK WIRE CONNECTOR [A SIDE] - HYBRID VEHICLE CONTROL ECU)

(a) Disconnect the zR3 No. 1 battery pack wire connector.





HINT
For the removal and installation procedures related to the No. 1 battery pack wire connector inspection, Removal.

(b) Disconnect the A76 hybrid vehicle control ECU connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for open):





Standard Resistance (Check for short):





(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage (Check for +B short):





HINT
If the power switch is turned on (IG) under the conditions above, DTCs may be stored. In this case, use the Techstream to clear the DTCs Hybrid Battery System.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. CHECK HARNESS AND CONNECTOR (NO. 1 BATTERY PACK WIRE CONNECTOR [B SIDE] - BATTERY SMART UNIT)

CAUTION:
Be sure to wear insulated gloves.

(a) Remove the HV battery Removal.





(b) Disconnect the z36 battery smart unit connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

6. REPLACE BATTERY SMART UNIT

HINT
For the removal and installation procedures related to the battery smart unit, Removal.

NEXT -- Continue to next step.

7. CLEAR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.

(d) Clear DTCs and freeze frame data.

NEXT -- Continue to next step.

8. RECONFIRM DTC OUTPUT

(a) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.

(b) Check if DTCs are output.

Result





B -- END (BATTERY SMART UNIT IS FAULTY)

A -- REPLACE HYBRID VEHICLE CONTROL ECU Removal

9. CHECK FUSE (IGCT3) P0A1F

NG -- REPLACE FUSE (IGCT3)
OK -- Continue to next step.

10. CHECK FUSE (IGCT NO. 2) P0A1F

NG -- REPLACE FUSE (IGCT NO. 2)
OK -- Continue to next step.

11. INSPECT RELAY (IGCT2) P0A1F

NG -- REPLACE RELAY (IGCT2)
OK -- Continue to next step.

12. CHECK HARNESS AND CONNECTOR (NO. 1 BATTERY PACK WIRE CONNECTOR [A SIDE] - IGCT2 RELAY) P0A1F

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- CHECK AND REPAIR POWER SOURCE CIRCUIT (IGCT2 RELAY POWER SOURCE)