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 battery cooling fan voltage, and sends the detected signals to the power management control ECU via serial communication.





WIRING DIAGRAM





INSPECTION PROCEDURE

CAUTION:
* If the battery cover is removed, install it before turning the power switch on (IG) or (READY). If the power switch is turned on (IG) or (READY) with the battery cover removed, U029A-123 may be set.
* Before inspecting the high-voltage system, take safety precautions to prevent electrical shocks, such as wearing insulated gloves and removing the service plug grip. 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.
HINT
At least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

PROCEDURE

1. CHECK DTC OUTPUT (HV)

(a) Connect the Techstream to the DLC3.

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

(c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

(d) Check for DTCs Hybrid Battery System.

Result:





(e) Disconnect the Techstream from the DLC3.

B -- GO TO DTC CHART Hybrid Battery System
A -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - BATTERY SMART UNIT)

CAUTION:
Be sure to wear insulated gloves.

(a) Disconnect the cable from the negative (-) battery terminal.

(b) Check that the service plug grip is not installed.

NOTICE:
After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(c) Disconnect connector L5 from the power management control ECU Removal.

(d) Remove the No. 1 hybrid vehicle battery carrier bracket sub-assembly Removal.

(e) Disconnect connector c1 from the battery smart unit.





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





Standard Resistance:





Text in Illustration





(g) Remove the IGCT NO. 2 fuse and AM2 fuse from the engine room junction block assembly.





Text in Illustration





(h) Disconnect all connectors from the power management control ECU.

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





Standard Resistance:





Text in Illustration





NOTICE:
When taking a measurement with a tester, do not apply excessive force to the tester probe to avoid damaging the holder.

(j) Connect the cable to the negative (-) battery terminal.

(k) Connect the battery smart unit connector.

(l) Install the No. 1 hybrid vehicle battery carrier bracket sub-assembly Installation.

(m) Connect the power management control ECU connectors Installation.

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

3. CHECK POWER MANAGEMENT CONTROL ECU

CAUTION:
Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:
After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Remove the No. 1 hybrid vehicle battery carrier bracket sub-assembly Removal.

(c) Disconnect connector c1 from the battery smart unit.





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

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

NOTICE:
Turning the power switch on (IG) with the service plug grip removed causes an interlock switch system DTC to be set. Use the Techstream to clear the DTCs Hybrid Battery System.





Standard Voltage:





Text in Illustration





(f) Turn the power switch off.

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





Standard Resistance:





Text in Illustration





HINT
Resistance becomes 2.0 kOhms or less when there is a short circuit in the power management control ECU.

(h) Connect the battery smart unit connector.

(i) Install the No. 1 hybrid vehicle battery carrier bracket sub-assembly Installation.

NG -- REPLACE POWER MANAGEMENT CONTROL ECU Components

OK -- REPLACE BATTERY SMART UNIT Components