Toyota Avalon (XX50): High Voltage Power Resource Circuit Voltage Sensor after Boosting Malfunction (P1C8349)

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Engine / Hybrid / Battery Control / Hybrid Control System / High Voltage Power Resource Circuit Voltage Sensor after Boosting Malfunction (P1C8349)

DTC SUMMARY

MALFUNCTION DESCRIPTION

The hybrid vehicle control ECU monitors the high-voltage wiring between the HV battery and inverter with converter assembly and detects a power supply malfunction.

The cause of this malfunction may be one of the following:

Inverter voltage sensor (VH) internal circuit malfunction
  • Voltage sensor (VH) malfunction
  • Motor generator control ECU (MG ECU) malfunction
  • Communication (wire harness) malfunction
High voltage system malfunction
  • HV battery malfunction
  • HV battery junction block assembly malfunction
  • Inverter with converter assembly malfunction
  • High-voltage wire harness malfunction
  • High-voltage connector or connection malfunction
Low-voltage circuit (12 V) malfunction
  • Hybrid vehicle control ECU malfunction
  • HV battery junction block assembly malfunction
  • Low voltage wire harness malfunction
  • Low voltage connector malfunction

INSPECTION DESCRIPTION

System Diagram Range

Inspection Content

Reason

Inspection Step

*a

Check connection condition and wire harness continuity between hybrid vehicle control ECU and HV battery junction block assembly

In order to check whether connectors are connected properly and to check for an open circuit in the SMRP and SMRB primary lines

3 to 7

*b

Check system main relay

Check whether SMRB and SMRP stuck OFF

8, 9

*c

Check connection condition and high-voltage cable continuity between HV battery junction block assembly and inverter with converter assembly

Check for open circuit and defective connection (arc marks) due to looseness

10 to 12

*d

Check high-voltage cable and connection condition between HV battery and HV battery junction block assembly

Check for open circuit and defective connection (arc marks) due to looseness

13, 14, 15, 16, 21

*e

Check HV battery

Check whether HV battery voltage has drastically dropped below normal range

17

DESCRIPTION

Refer to the description for DTC P0AE411.

Click here

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P1C8349

High Voltage Power Resource Circuit Voltage Sensor after Boosting Malfunction

Although an SMR on request was sent when the power switch is operated, the voltage did not increase after boosting.

High-voltage circuit malfunctions between the HV battery and inverter with converter assembly.

The EV electric battery fuse is blown, the service plug grip is removed, the system main resistor is blown, SMRP or SMRB remains open, or the high-voltage cable has an open circuit.

(1 trip detection logic)
  • HV battery junction block assembly
  • HV floor under wire
  • Inverter with converter assembly
  • HV battery
  • Wire harness or connector
  • Hybrid battery terminal block

Does not come on

Master Warning Light:

Comes on
Related Data List

DTC No.

Data List

P1C8349
  • Hybrid Battery Voltage
  • Hybrid Battery Current
  • VL-Voltage before Boosting
  • VH-Voltage after Boosting

The following items can be helpful when performing repairs:

Data List
  • Ready Signal
  • Inter Lock Switch
  • SMRP Status
  • SMRB Status
  • SMRG Status

CONFIRMATION DRIVING PATTERN

HINT:

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

Click here

  1. Connect the Techstream to the DLC3.
  2. Turn the power switch on (IG) and turn the Techstream on.
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  4. Turn the power switch off and wait for 2 minutes or more.
  5. Turn the power switch on (READY) and wait for 30 seconds or more.
  6. Turn the power switch off and wait for 2 minutes or more.
  7. Turn the power switch on (IG) and turn the Techstream on.
  8. Enter the following menus: Powertrain / Hybrid Control / Utility / All Readiness.
  9. 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.

WIRING DIAGRAM

Refer to the wiring diagram for DTC P0AA649.

Click here

Refer to the wiring diagram for the HV battery high-voltage line circuit.

Click here

CAUTION / NOTICE / HINT

CAUTION:

  • Before the following operations are conducted, take precautions to prevent electric shock by turning the power switch off, wearing insulated gloves, and removing the service plug grip from HV battery.
    • Inspecting the high-voltage system
    • Disconnecting the low voltage connector of the inverter with converter assembly
    • Disconnecting the low voltage connector of the HV battery
  • To prevent electric shock, make sure to remove the service plug grip to cut off the high voltage circuit before servicing the vehicle.
  • After removing the service plug grip from the HV battery, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
  • After removing 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.

    Click here

    HINT:

    Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

    *a

    Without waiting for 10 minutes
  • When disposing of an HV battery, make sure to return it through an authorized collection agent who is capable of handling it safely. If the HV battery is returned via the manufacturer specified route, it will be returned properly and in a safe manner by an authorized collection agent.

    *a

    Dealer

    *b

    Battery Collection Agent
  • Before returning the HV battery, make sure to perform a recovery inspection.
  • Make a note of the output DTCs as some of them may be necessary for recovery inspection of the HV battery.

NOTICE:

After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

Click here

PROCEDURE

1.

CHECK DTC OUTPUT (HYBRID CONTROL, MOTOR GENERATOR)

(a) Connect the Techstream to the DLC3.

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

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

(d) Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes Powertrain > Motor Generator > Trouble Codes

Result

Proceed to

P1C8349 only is output, or DTCs except the ones in the table below are also output.

A

DTCs of hybrid control system in the tables below are output.

B

DTCs of motor generator control system in the tables below are output.

C

Malfunction Content

System

Relevant DTC

Microcomputer malfunction

Hybrid control system

P0A1B49

Drive Motor "A" Control Module Internal Electronic Failure

P060647

Hybrid/EV Powertrain Control Module Processor Watchdog / Safety MCU Failure

P060687

Hybrid/EV Powertrain Control Module Processor to Monitoring Processor Missing Message

P060A47

Hybrid/EV Powertrain Control Module Monitoring Processor Watchdog / Safety MCU Failure

P060A87

Hybrid/EV Powertrain Control Module Processor from Monitoring Processor Missing Message

P1C9E9F

Hybrid/EV System Reset Stuck Off

P0AFC96

Hybrid/EV Battery Sensor Module Component Internal Failure

P0AFC00

Hybrid/EV Battery Sensor Module

Motor generator control system

P0A1B1F

Generator Control Module Circuit Intermittent

P0A1A47

Generator Control Module Watchdog / Safety ОјC Failure

P0A1A49

Generator Control Module Internal Electronic Failure

P1C2A1C

Generator A/D Converter Circuit Circuit Voltage Out of Range

P1C2A49

Generator A/D Converter Circuit Internal Electronic Failure

P313383

Communication Error from Generator to Drive Motor "A" Value of Signal Protection Calculation Incorrect

P313386

Communication Error from Generator to Drive Motor "A" Signal Invalid

P313387

Communication Error from Generator to Drive Motor "A" Missing Message

Power source circuit malfunction

Hybrid control system

P0AFC16

Hybrid/EV Battery Sensor Module Circuit Voltage Below Threshold

Motor generator control system

P06D61C

Generator Control Module Offset Power Circuit Voltage Out of Range

Communication system malfunction

Hybrid control system

P312387

Lost Communication with Drive Motor Control Module "A" from Hybrid/EV Control Module Missing Message

U029A87

Lost Communication with Hybrid/EV Battery Sensor Module Missing Message

Sensor and actuator circuit malfunction

Hybrid control system

P0AD915

Hybrid/EV Battery Positive Contactor Circuit Short to Auxiliary Battery or Open

P0AD911

Hybrid/EV Battery Positive Contactor Circuit Short to Ground

P0AE415

Hybrid/EV Battery Precharge Contactor Circuit Short to Auxiliary Battery or Open

P0AE411

Hybrid/EV Battery Precharge Contactor Circuit Short to Ground

P0ADD15

Hybrid/EV Battery Negative Contactor Circuit Short to Auxiliary Battery or Open

P0ADD11

Hybrid/EV Battery Negative Contactor Circuit Short to Ground

P0ABF11

Hybrid/EV Battery Current Sensor "A" Circuit Short to Ground

P0ABF15

Hybrid/EV Battery Current Sensor "A" Circuit Short to Auxiliary Battery or Open

P0B3B14

Hybrid/EV Battery Voltage Sensor "A" Circuit Short to Ground or Open

P0B4014

Hybrid/EV Battery Voltage Sensor "B" Circuit Short to Ground or Open

P0B4514

Hybrid/EV Battery Voltage Sensor "C" Circuit Short to Ground or Open

P0B4A14

Hybrid/EV Battery Voltage Sensor "D" Circuit Short to Ground or Open

P0B4F14

Hybrid/EV Battery Voltage Sensor "E" Circuit Short to Ground or Open

P0B5414

Hybrid/EV Battery Voltage Sensor "F" Circuit Short to Ground or Open

P0B5914

Hybrid/EV Battery Voltage Sensor "G" Circuit Short to Ground or Open

P0B5E14

Hybrid/EV Battery Voltage Sensor "H" Circuit Short to Ground or Open

P0B6314

Hybrid/EV Battery Voltage Sensor "I" Circuit Short to Ground or Open

P0B6814

Hybrid/EV Battery Voltage Sensor "J" Circuit Short to Ground or Open

P0B6D14

Hybrid/EV Battery Voltage Sensor "K" Circuit Short to Ground or Open

P0B7214

Hybrid/EV Battery Voltage Sensor "L" Circuit Short to Ground or Open

P308A13

Hybrid/EV Battery Voltage Sensor All Circuit Open

P0AFC62

Hybrid/EV Battery Sensor Module Signal Compare Failure

P0B231C

Hybrid/EV Battery "A" Voltage Sensor Voltage Out of Range

P308A12

Hybrid/EV Battery Voltage Sensor All Circuit Short to Auxiliary Battery

P0ABF00

Hybrid/EV Battery Current Sensor "A" Circuit Range/Performance

P0ABF28

Hybrid/EV Battery Current Sensor "A" Signal Bias Level Out of Range / Zero Adjustment Failure

P0ABF2A

Hybrid/EV Battery Current Sensor "A" Signal Stuck In Range

System malfunction

Hybrid control system

P0C7600

Hybrid/EV Battery System Discharge Time Too Long

P0D2D1C

Drive Motor "A" Inverter Voltage Sensor Voltage Out of Range

P1C8149

High Voltage Power Resource Circuit Consumption Circuit Short

P1C8249

High Voltage Power Resource Circuit Over Loading

P300449

High Voltage Power Resource Circuit Short during Pre-Charge

Motor generator control system

P0D2D16

Drive Motor "A" Inverter Voltage Sensor(VH) Circuit Voltage Below Threshold

P0D2D17

Drive Motor "A" Inverter Voltage Sensor(VH) Circuit Voltage Above Threshold

P1CB69E

Drive Motor "A" Inverter Voltage Sensor(VH) Stuck On

P0CA300

DC/DC Converter Step Up Voltage Performance

HINT:

  • P1C8349 may be output as a result of the malfunction indicated by the DTCs above.
    1. The chart above is listed in inspection order of priority.
    2. Check DTCs that are output at the same time by following the listed order. (The main cause of the malfunction can be determined without performing unnecessary inspections.)

(e) Turn the power switch off.

B

GO TO DTC CHART (HYBRID CONTROL SYSTEM)

C

GO TO DTC CHART (MOTOR GENERATOR CONTROL SYSTEM)

A

2.

CHECK FREEZE FRAME DATA (HYBRID CONTROL)

(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) Read the freeze frame data of DTC P1C8349.

Result

Proceed to

All of the following conditions are met:

  • Difference between "Hybrid Battery Voltage" and "VL-Voltage before Boosting" is 39 V or less.
  • Difference between "Hybrid Battery Voltage" and "VH-Voltage after Boosting" is more than 60 V.
  • Difference between "VL-Voltage before Boosting" and "VH-Voltage after Boosting" is more than 76 V.

A

In addition to the above conditions, "Hybrid Battery Current" is 3 A or more.

B

Except above

C

(e) Turn the power switch off.

A

REPLACE INVERTER WITH CONVERTER ASSEMBLY

B

GO TO DTC CHART (P1C8149)

C

3.

CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)

Click here

NG

CONNECT SECURELY
OK

4.

CHECK CONNECTOR CONNECTION CONDITION (FLOOR WIRE CONNECTOR)

Click here

Result

Proceed to

OK

A

NG (The connector is not connected securely.)

B

NG (The terminals are not making secure contact or are deformed, or water or foreign matter exists in the connector.)

C
B

CONNECT SECURELY
C

REPAIR OR REPLACE HARNESS OR CONNECTOR
A

5.

CHECK CONNECTOR CONNECTION CONDITION (HV BATTERY JUNCTION BLOCK ASSEMBLY CONNECTOR)

Click here

NG

CONNECT SECURELY
OK

6.

CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - HV BATTERY JUNCTION BLOCK ASSEMBLY)

Click here

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

7.

CHECK HARNESS AND CONNECTOR (HV BATTERY JUNCTION BLOCK ASSEMBLY - BODY GROUND)

Click here

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

8.

INSPECT HV BATTERY JUNCTION BLOCK ASSEMBLY (SMRB)

Click here

NG

REPLACE HV BATTERY JUNCTION BLOCK ASSEMBLY

OK

9.

INSPECT HV BATTERY JUNCTION BLOCK ASSEMBLY (SMRP)

Click here

NG

REPLACE HV BATTERY JUNCTION BLOCK ASSEMBLY

OK

10.

CHECK INVERTER WITH CONVERTER ASSEMBLY (HV FLOOR UNDER WIRE)

Click here

Result

Proceed to

The terminals are connected securely and there are no contact problems.

There are no arc marks.

A

The terminals are not connected securely and there is a contact problem.

There are arc marks.

B

The terminals are not connected securely and there is a contact problem.

There are no arc marks.

C

The terminals are connected securely and there are no contact problems.

There are arc marks.

B
B

REPLACE MALFUNCTIONING PARTS
C

CONNECT SECURELY
A

11.

CHECK HV BATTERY JUNCTION BLOCK ASSEMBLY (HV FLOOR UNDER WIRE)

Click here

Result

Proceed to

The terminals are connected securely and there are no contact problems.

There are no arc marks.

A

The terminals are not connected securely and there is a contact problem.

There are arc marks.

B

The terminals are not connected securely and there is a contact problem.

There are no arc marks.

C

The terminals are connected securely and there are no contact problems.

There are arc marks.

B
B

REPLACE MALFUNCTIONING PARTS
C

CONNECT SECURELY
A

12.

CHECK HV FLOOR UNDER WIRE

Click here

NG

REPLACE HV FLOOR UNDER WIRE

OK

13.

CHECK HV BATTERY JUNCTION BLOCK ASSEMBLY (HV BATTERY HIGH VOLTAGE CONNECTOR CONNECTION CONDITION)

Click here

Result

Proceed to

The terminals are connected securely and there are no contact problems.

There are no arc marks.

A

The terminals are not connected securely and there is a contact problem.

There are arc marks.

B

The terminals are not connected securely and there is a contact problem.

There are no arc marks.

C

The terminals are connected securely and there are no contact problems.

There are arc marks.

B
B

REPLACE MALFUNCTIONING PARTS
C

CONNECT SECURELY
A

14.

CHECK HV BATTERY HIGH VOLTAGE CABLE

Click here

NG

REPLACE HV BATTERY

OK

15.

CHECK HV BATTERY

Click here

NG

GO TO STEP 19

OK

16.

CHECK FOR INTERMITTENT PROBLEMS

Click here

NEXT

17.

CLEAR DTC

Click here

NEXT

18.

CHECK DTC OUTPUT (HYBRID CONTROL)

(a) Connect the Techstream to the DLC3.

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

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

(d) Check if DTCs are output (including pending DTCs).

Powertrain > Hybrid Control > Trouble Codes

Result

Proceed to

No DTCs are output.

A

DTC P300449 is output.

B

DTC P1C8349 is output.

C

HINT:

Because P300449 uses 2-trip detection logic, the DTC detection conditions need to be met 2 times.

(e) Turn the power switch off.

A

REPLACE INVERTER WITH CONVERTER ASSEMBLY

B

GO TO DTC CHART (P300449)

C

REPLACE INVERTER WITH CONVERTER ASSEMBLY

19.

CHECK HYBRID BATTERY TERMINAL BLOCK (HV BATTERY HIGH VOLTAGE CONNECTOR CONNECTION CONDITION)

Click here

Result

Proceed to

The terminals are connected securely and there are no contact problems.

There are no arc marks.

A

The terminals are not connected securely and there is a contact problem.

There are arc marks.

B

The terminals are not connected securely and there is a contact problem.

There are no arc marks.

C

The terminals are connected securely and there are no contact problems.

There are arc marks.

B
B

REPLACE MALFUNCTIONING PARTS
C

CONNECT SECURELY
A

20.

CHECK HV BATTERY HIGH VOLTAGE CABLE

Click here

NG

REPLACE HV BATTERY

OK

21.

CHECK HYBRID BATTERY TERMINAL BLOCK

Click here

OK

REPLACE HV BATTERY

NG

REPLACE HYBRID BATTERY TERMINAL BLOCK

Hybrid/EV Battery Current Sensor for Driving Control Circuit Short to Ground (P1C9F11,P1C9F15). Engine Failed to Start Mechanical Linkage Failure (P1C7779). High Voltage Power Resource Circuit Consump

High Voltage Power Resource Circuit Short during Ready ON (P1C8449)

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Toyota Avalon (XX50) 2019-2022 Service & Repair Manual

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