Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: System Voltage Circuit Short to Ground or Open (P056014)

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Drivetrain / U881f (automatic Transmission / Transaxle) / Automatic Transaxle System / System Voltage Circuit Short to Ground or Open (P056014)

DESCRIPTION

The battery supplies electricity to the ECM even when the engine switch is off. This power allows the ECM to store data such as DTC history and freeze frame data. If the battery voltage falls below a minimum level, the stored ECM data will be cleared and the ECM will determine that there is a malfunction in the power supply circuit. The next time the engine is started, the ECM will illuminate the MIL and store this DTC.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

Note

P056014

System Voltage Circuit Short to Ground or Open

1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other

  • Always
  • Low ECM back-up power source circuit voltage
  • 3 seconds or more
  • 1-trip detection logic
  • Back-up power source circuit
  • Battery terminals
  • Battery
  • ECM

Comes on

DTC stored

SAE Code:

P0562

HINT:

If DTC P056014 is stored, the ECM will not store other DTCs.

MONITOR STRATEGY

Related DTCs

P0562: ECM system voltage

Required Sensors/Components (Main)

ECM

Required Sensors/Components (Sub)

-

Frequency of operation

Continuous

Duration

3 sec.

MIL operation

Immediate

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

The monitor will run whenever the following DTCs are not present

None

Battery voltage

8 V or more

Engine switch

On (IG)

Starter

OFF

TYPICAL MALFUNCTION THRESHOLDS

Continuous battery voltage

Less than 3.5 V

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.
  • When clearing the permanent DTCs, refer to the Clear Permanent DTC procedure.

    Click here

  1. Connect the Techstream to the DLC3.
  2. Turn the engine 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 engine switch off and wait for 2 minutes or more.
  5. Turn the engine switch on (IG) and turn the Techstream on.
  6. Wait for 3 seconds or more with the engine switch on (IG). [*1]

    HINT:

    [*1] : Normal judgment procedure.

    The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.

  7. Enter the following menus: Powertrain / Transmission / Utility / All Readiness.
  8. Input the DTC: P056014.
  9. 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.
    • If the judgment result shows INCOMPLETE or N/A, perform the normal judgment procedure again.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • Perform the universal trip to clear permanent DTCs.

    Click here

  • Perform registration and/or initialization when parts related to the automatic transaxle are replaced.

    Click here

PROCEDURE

1.

INSPECT BATTERY

(a) Check that the battery is not depleted.

Click here

OK:

Battery is not depleted

NG

CHARGE OR REPLACE BATTERY
OK

2.

CHECK BATTERY TERMINAL

(a) Check that the battery terminals are not loose or corroded.

OK:

Battery terminals are not loose or corroded

NG

REPAIR OR REPLACE BATTERY TERMINAL
OK

3.

CHECK TERMINAL VOLTAGE (POWER SOURCE OF ECM)

(a) Disconnect the A37 ECM connector.

*a

Front view of wire harness connector

(to ECM)

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A37-1 (BATT) - Body ground

Always

11 to 14 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - ECM)
OK

4.

CHECK WHETHER DTC OUTPUT RECURS (DTC P056014)

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(d) Clear the DTCs.

Click here

Powertrain > Transmission > Clear DTCs

(e) Turn the engine switch off and wait for at least 30 seconds.

(f) Turn the engine switch on (IG).

(g) Turn the Techstream on.

(h) Wait 5 seconds or more.

(i) Enter the following menus: Powertrain / Transmission / Trouble Codes.

Powertrain > Transmission > Trouble Codes

(j) Read the DTCs.

Result

Proceed to

DTC P056014 is output

A

DTCs are not output

B
B

CHECK FOR INTERMITTENT PROBLEMS

A

5.

REPLACE ECM

(a) Replace the ECM.

Click here

NEXT

PERFORM A/T CODE REGISTRATION

    Diagnostic Trouble Code Chart
    DIAGNOSTIC TROUBLE CODE CHART Automatic Transaxle System DTC No. Detection Item MIL Memory Note Link P056014 System Voltage Circuit Short to Ground or Open Comes on DTC stored ...

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