Lexus ES: Hybrid/EV Battery Internal Electronic Failure (P31B549)
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 |
| 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.
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- 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).
(c) Enter the following menus: Powertrain / HV Battery and Hybrid Control / Trouble Codes.
(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.
| A | .gif) | REPLACE HYBRID VEHICLE CONTROL ECU |
| B | | GO TO DTC CHART (HYBRID BATTERY SYSTEM) |
| C | | GO TO DTC CHART (HYBRID CONTROL SYSTEM) |
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DESCRIPTION The HV battery is composed of 70 cells (3.7 V each) in series. The battery ECU assembly monitors the internal resistance of each HV battery cell to detect malfunctions of the HV battery.
Hybrid/EV Battery Stack 1 Circuit Resistance Above Threshold (P33E01B,P33E11B)
DESCRIPTION The HV battery is composed of 70 cells (3.7 V each) in series. The battery ECU assembly monitors the internal resistance of each HV battery cell to detect malfunctions of the HV battery.
(Extreme) Hybrid/EV Battery Stack 1 Cell Circuit Voltage Below Threshold (P33EC16,P33ED16)
DESCRIPTION If the voltage of an HV battery cell is lower than the threshold for a certain amount of time, the battery ECU assembly will interpret this as a malfunction. DTC No. Detection Item
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Power Source Circuit
DESCRIPTION This circuit provides power to operate the blind spot monitor sensor. WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE: Inspect the fuses for circuits related to this system before performing the following procedure. PROCEDURE 1. CHECK HARNESS AND CONNECTOR (BLIND SPOT MONITOR SENSOR
Data List / Active Test
DATA LIST / ACTIVE TEST DATA LIST NOTICE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not. HINT: Using the Techstream to read the Data List allows the values or states of
