HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): P31B549; Hybrid/EV Battery Internal Electronic Failure; 2021 - 2022 MY Avalon HV [08/2020

Last Modified: 08-21-2023	6.11:8.1.0	Doc ID: RM100000001RK1R
Model Year Start: 2021	Model: Avalon HV	Prod Date Range: [08/2020 - ]
Title: HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): P31B549; Hybrid/EV Battery Internal Electronic Failure; 2021 - 2022 MY Avalon HV [08/2020 - ]

DTC

P31B549

Hybrid/EV Battery Internal Electronic Failure

DESCRIPTION

The battery ECU assembly monitors its internal operation and will store these DTCs when it detects an internal malfunction.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P31B549

Hybrid/EV Battery Internal Electronic Failure

An abnormal signal is detected by the battery ECU assembly (excessive discharging current).

(1 trip detection logic)

Hybrid vehicle control ECU

Does not come on

Master Warning Light:

Comes on

Related Data List

DTC No.	Data List
P31B549	Hybrid/EV Battery Current

CONFIRMATION DRIVING PATTERN

HINT:

After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

Click here

Connect the Techstream to the DLC3.
Turn the power switch on (IG) and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the power switch off and wait for 2 minutes or more.
Turn the power switch on (IG) and turn the Techstream on.
Drive the vehicle on urban roads for approximately 10 minutes.
Enter the following menus: Powertrain / HV battery / Utility / All Readiness.
Check the DTC judgment result.
HINT:
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows INCOMPLETE or N/A, perform driving pattern again.

PROCEDURE

1.	CHECK DTC OUTPUT (HV BATTERY, HYBRID CONTROL)

(a) Connect the Techstream to the DLC3.

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

(d) Check for DTCs.

Powertrain > HV Battery > Trouble Codes

Powertrain > Hybrid Control > Trouble Codes

Result	Proceed to
"P31B549" only is output.	A
DTCs except "P31B549" of hybrid battery system are output.	B
DTCs except "P31B549" of hybrid control system are output.	C

(e) Turn the power switch off.

REPLACE HYBRID VEHICLE CONTROL ECU

GO TO DTC CHART (HYBRID BATTERY SYSTEM)

GO TO DTC CHART (HYBRID CONTROL SYSTEM)