Lexus NX: Lost Communication with Hybrid Vehicle Control System (U0293)

Lexus NX Service Manual / Engine & Hybrid System / 2ar-fxe (engine Control) / Sfi System / Lost Communication with Hybrid Vehicle Control System (U0293)

MONITOR DESCRIPTION

The ECM communicates with the hybrid vehicle control ECU. When the ECM does not receive data from the hybrid vehicle control ECU, the ECM illuminates the MIL and stores a DTC.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

U0293

Lost Communication with Hybrid Vehicle Control System

Communication with hybrid vehicle control ECU is interrupted (1 trip detection logic).

  • Wire harness
  • Hybrid vehicle control ECU
  • ECM

Comes on

DTC stored

MONITOR STRATEGY

Related DTCs

U0293: Lost communication with hybrid control module

Required Sensors/Components (Main)

ECM

Required Sensors/Components (Related)

-

Frequency of Operation

Continuous

Duration

0.576 seconds

MIL Operation

Immediate

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored

None

Both of the following conditions are met

-

Auxiliary battery Voltage

10.5 V or higher

Power switch

On (IG)

TYPICAL MALFUNCTION THRESHOLDS

Communication signal

Lost communication with hybrid control module

CONFIRMATION DRIVING PATTERN

  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 at least 30 seconds.
  5. Turn the power switch on (IG) and turn the Techstream on.
  6. Wait 5 seconds or more.
  7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
  8. Read the pending DTCs.

    HINT:

    • If a pending DTC is output, the system is malfunctioning.
    • If a pending DTC is not output, perform the following procedure.
  9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  10. Input the DTC: U0293.
  11. Check the DTC judgment result.

    Techstream Display

    Description

    NORMAL

    • DTC judgment completed
    • System normal

    ABNORMAL

    • DTC judgment completed
    • System abnormal

    INCOMPLETE

    • DTC judgment not completed
    • Perform driving pattern after confirming DTC enabling conditions

    N/A

    • Unable to perform DTC judgment
    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT:

    • If the judgment result shows NORMAL, the system is normal.
    • If the judgment result shows ABNORMAL, the system has a malfunction.
  12. If the test result is INCOMPLETE or N/A and no DTC is output, perform a universal trip and check for permanent DTCs

    HINT:

    • If a permanent DTC is output, the system is malfunctioning.
    • If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

1.

GO TO CAN COMMUNICATION SYSTEM

(a) Refer to the CAN Communication System.

Click here

NEXT

END

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