Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001GCL1
Model Year Start: 2020 Model: Corolla Prod Date Range: [01/2019 - 09/2022]
Title: HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P253012; IG2 Signal Circuit Short to Auxiliary Battery; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

DTC

P253012

IG2 Signal Circuit Short to Auxiliary Battery

DESCRIPTION

The hybrid vehicle control ECU compares the IG2 signal to the IG control status signal sent from the certification ECU (smart key ECU assembly) to detect a stuck on malfunction of the IG2 signal.

HINT:

If DTC P253012 is stored, the power switch will turn off (READY off).

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P253012

IG2 Signal Circuit Short to Auxiliary Battery

The IG2 signal of the hybrid vehicle control ECU and the IG control status signal sent from the certification ECU (smart key ECU assembly) do not match.

(1 trip detection logic)
  • Auxiliary battery
  • Certification ECU (smart key ECU assembly)
  • Hybrid vehicle control ECU
  • ECM
  • NO. 1 integration relay
  • Wire harness or connector

Does not come on

Master Warning: Comes on

CONFIRMATION DRIVING PATTERN

HINT:

After repair has 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 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): UTILITY

  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 (IG) and wait for 15 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

CAUTION / NOTICE / HINT

NOTICE:

Before replacing the certification ECU (smart key ECU assembly), refer to Registration.

Click here 2020 MY Corolla Corolla HV [01/2019 - 04/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION

PROCEDURE

1.

CHECK AUXILIARY BATTERY VOLTAGE

(a) Turn the power switch off and turn on the high beam headlights for 30 seconds. This will remove the surface charge from the auxiliary battery.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

Positive (+) auxiliary battery terminal - Negative (-) auxiliary battery terminal

20°C (68°F), Power switch off

12.0 V or higher
OK

GO TO STEP 3

NG

2.

CHARGE OR REPLACE AUXILIARY BATTERY

(a) Charge or replace the auxiliary battery.

NEXT

3.

CLEAR DTC

(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) Clear the DTCs.

Powertrain > Hybrid Control > Clear DTCs

(e) Turn the power switch off.

NEXT

4.

CHECK DTC OUTPUT (HYBRID CONTROL)

(a) Turn the power switch on (IG) and wait for 15 seconds or more.

(b) Turn the power switch off and wait for 2 minutes or more.

(c) Connect the Techstream to the DLC3.

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

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

(f) Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes

Result

Proceed to

P253012 is output

A

P253012 is not output

B

(g) Turn the power switch off.

B

CHECK FOR INTERMITTENT PROBLEMS

A

5.

CHECK DTC OUTPUT (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) Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes

Result

Proceed to

U011087, U012987, U014087, U015187, U016487 or U117087 is also output

A

U011087, U012987, U014087, U015187, U016487 or U117087 is not output

B

(e) Turn the power switch off.

B

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL

A

6.

CHECK HYBRID VEHICLE CONTROL ECU

(a) Disconnect the I2 hybrid vehicle control ECU connector.

*a

Front view of wire harness connector

(to Hybrid Vehicle Control ECU)

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

Condition:

Tester Connection

Condition

I2-35 (IG2) - I2-12 (E01)

Power switch off

(c) Reconnect the I2 hybrid vehicle control ECU connector.

Result

Proceed to

9 V or higher

A

Below 9 V

B
B

REPLACE HYBRID VEHICLE CONTROL ECU 2020 MY Corolla Corolla HV [01/2019 - 04/2020]; HYBRID / BATTERY CONTROL: HYBRID VEHICLE CONTROL ECU: REMOVAL 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID VEHICLE CONTROL ECU: REMOVAL

A

7.

CHECK ECM

(a) Disconnect the I2 hybrid vehicle control ECU connector.

*a

Front view of wire harness connector

(to Hybrid Vehicle Control ECU)

(b) Disconnect the A46 and C77 ECM connectors.

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

Condition:

Tester Connection

Condition

I2-35 (IG2) - I2-12 (E01)

Power switch off

(d) Reconnect the A46 and C77 ECM connectors.

(e) Reconnect the I2 hybrid vehicle control ECU connector.

Result

Proceed to

9 V or higher

A

Below 9 V

B
B

REPLACE ECM 2020 MY Corolla Corolla HV [01/2019 - 04/2020]; 2ZR-FXE (ENGINE CONTROL): ECM: REMOVAL 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; 2ZR-FXE (ENGINE CONTROL): ECM: REMOVAL

A

8.

INSPECT NO. 1 INTEGRATION RELAY (IG2 NO. 1 RELAY)

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NG

REPLACE NO. 1 INTEGRATION RELAY 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; POWER DISTRIBUTION: INTEGRATION RELAY: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; POWER DISTRIBUTION: INTEGRATION RELAY: REMOVAL

OK

9.

CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - NO. 1 INTEGRATION RELAY)

(a) Disconnect the I2 hybrid vehicle control ECU connector.

(b) Remove the NO. 1 integration relay from the No. 1 engine room relay block and No. 1 junction block assembly.

Click here 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; POWER DISTRIBUTION: INTEGRATION RELAY: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; POWER DISTRIBUTION: INTEGRATION RELAY: REMOVAL

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

I2-35 (IG2) - Body ground

Power switch off

1 V or less

*a

Front view of wire harness connector

(to Hybrid Vehicle Control ECU)

(d) Install the NO. 1 integration relay.

(e) Reconnect the I2 hybrid vehicle control ECU connector.

OK

(a) Check for intermittent problems.

Click here CHECK FOR INTERMITTENT PROBLEMS

(1) Check the connection and terminal contact pressure of the connectors and wire harnesses between the hybrid vehicle control ECU and the No. 1 engine room relay block and No. 1 junction block assembly.

(2) When the power switch is on (READY), jiggle the connectors and wire harnesses between the hybrid vehicle control ECU and the No. 1 engine room relay block and No. 1 junction block assembly.
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR