Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001HWD4
Model Year Start: 2020 Model: GR Corolla Prod Date Range: [03/2019 - 09/2022]
Title: DOOR LOCK: WIRELESS DOOR LOCK CONTROL SYSTEM (for Gasoline Model, with Smart Key System): B1242; Wireless Door Lock Tuner Circuit Malfunction; 2020 - 2022 MY Corolla Corolla Hatchback GR Corolla [03/2019 - 09/2022]

DTC

B1242

Wireless Door Lock Tuner Circuit Malfunction

DESCRIPTION

The door control receiver is used to receive radio waves related to the entry functions of the electrical key transmitter sub-assembly. The certification ECU (smart key ECU assembly) decodes the requested electrical key transmitter sub-assembly operation by identifying a key code based on the radio waves received via the door control receiver. The door control receiver receives a signal from the electrical key transmitter sub-assembly and sends signals to the main body ECU (multiplex network body ECU) through the certification ECU (smart key ECU assembly). (ex. If a door lock operation is requested, the certification ECU (smart key ECU assembly) sends a door lock command to the main body ECU (multiplex network body ECU)).

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B1242

Wireless Door Lock Tuner Circuit Malfunction
  • Short to ground in RDAM terminal circuit between the certification ECU (smart key ECU assembly) and door control receiver.
  • Short to ground in RDAM terminal circuit when voltage (5 V) is not being output from terminal RCO
  • Wire harness or connector
  • Door control receiver
  • Certification ECU (smart key ECU assembly)

WIRING DIAGRAM

for 12 Pin Type

for 5 Pin Type

CAUTION / NOTICE / HINT

NOTICE:

  • When using the Techstream with the engine switch off, connect the Techstream to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and the vehicle begins. Then select Model Code "KEY REGIST" under manual mode and enter the following menus: Body Electrical / Smart Key(CAN). While using the Techstream, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the Techstream and the vehicle.
  • Before replacing the certification ECU (smart key ECU assembly), refer to Registration.

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

  • When replacing or inspecting the door control receiver and wire harness, do not change the position or length of the wire harness. If the wire harness is too close to the door control receiver, the performance of the entry function and wireless function may be affected.
  • This DTC is not stored within 10 seconds of the engine switch being turned from on (IG) to off.
  • Make sure that there are no electrical key transmitter sub-assemblies in the vehicle.
  • When replacing the electrical key and tire pressure monitoring system receiver assembly, read the transmitter IDs (tire pressure warning system) stored in the old ECU using the Techstream and write them down before removal.

    Click here 2020 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 09/2019]; TIRE PRESSURE MONITORING: TIRE PRESSURE WARNING SYSTEM (for Gasoline Model (for Type A)): REGISTRATION 2020 - 2023 MY Corolla Corolla Hatchback GR Corolla [09/2019 - 11/2022]; TIRE PRESSURE MONITORING: TIRE PRESSURE WARNING SYSTEM (for Gasoline Model (for Type A)): REGISTRATION

  • If the electrical key and tire pressure monitoring system receiver assembly has been replaced, it is necessary to perform initialization (Click here 2019 - 2023 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 11/2022]; TIRE PRESSURE MONITORING: TIRE PRESSURE WARNING SYSTEM (for Gasoline Model (for Type A)): INITIALIZATION ) after registration (Click here 2020 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 09/2019]; TIRE PRESSURE MONITORING: TIRE PRESSURE WARNING SYSTEM (for Gasoline Model (for Type A)): REGISTRATION 2020 - 2023 MY Corolla Corolla Hatchback GR Corolla [09/2019 - 11/2022]; TIRE PRESSURE MONITORING: TIRE PRESSURE WARNING SYSTEM (for Gasoline Model (for Type A)): REGISTRATION ) of the transmitter IDs to the electrical key and tire pressure monitoring system receiver assembly.

PROCEDURE

1.

CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Disconnect the O18*1 or O38*2 door control receiver connector.

  • *1: for 12 Pin Type
  • *2: for 5 Pin Type

(b) Measure the voltage and resistance and check for pulses according to the value(s) in the table below.

*a

Component with harness connected

(Certification ECU (Smart Key ECU Assembly))

-

-

Standard Resistance:

Tester Connection

Condition

Specified Condition

I1-18 (E) - Body ground

Always

Below 1 Ω

Standard Voltage:

Tester Connection

Condition

Specified Condition

O61-21 (RDAM) - I1-18 (E)

Always

11 to 14 V

O61-18 (RCO) - I1-18 (E)

Always

Below 1 V → 4.5 to 5.5 V pulse generation at regular intervals

Result

Proceed to

OK (for 12 Pin Type)

A

OK (for 5 Pin Type)

B

NG

C
A

REPLACE ELECTRICAL KEY AND TIRE PRESSURE MONITORING SYSTEM RECEIVER ASSEMBLY

for Hatchback: Click here 2019 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - 09/2022]; DOOR LOCK: DOOR CONTROL RECEIVER (for Hatchback): REMOVAL

for Sedan: Click here 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 04/2020]; DOOR LOCK: DOOR CONTROL RECEIVER (for Sedan with Tire Pressure Warning System): REMOVAL 2021 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [04/2020 - 09/2022]; DOOR LOCK: DOOR CONTROL RECEIVER (for Sedan with Tire Pressure Warning System): REMOVAL

B

REPLACE SMART DOOR CONTROL RECEIVER ASSEMBLY 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 04/2020]; DOOR LOCK: DOOR CONTROL RECEIVER (for Sedan without Tire Pressure Warning System): REMOVAL 2021 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [04/2020 - 09/2022]; DOOR LOCK: DOOR CONTROL RECEIVER (for Sedan without Tire Pressure Warning System): REMOVAL

C

2.

CHECK HARNESS AND CONNECTOR (DOOR CONTROL RECEIVER - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))

(a) Disconnect the O61 certification ECU (smart key ECU assembly) connector.

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

Standard Resistance:

for 12 Pin Type

Tester Connection

Condition

Specified Condition

O61-21 (RDAM) - O18-2 (DATA)

Always

Below 1 Ω

O61-18 (RCO) - O18-8 (+5)

Always

Below 1 Ω

O18-12 (GND) - Body ground

Always

Below 1 Ω

O18-2 (DATA) or O61-21 (RDAM) - Other terminals and body ground

Always

10 kΩ or higher

O18-8 (+5) or O61-18 (RCO) - Other terminals and body ground

Always

10 kΩ or higher

for 5 Pin Type

Tester Connection

Condition

Specified Condition

O61-21 (RDAM) - O38-5 (DATA)

Always

Below 1 Ω

O61-18 (RCO) - O38-4 (+5)

Always

Below 1 Ω

O38-1 (GND) - Body ground

Always

Below 1 Ω

O61-21 (RDAM) or O38-5 (DATA) - Other terminals and body ground

Always

10 kΩ or higher

O61-18 (RCO) or O38-4 (+5) - Other terminals and body ground

Always

10 kΩ or higher
OK

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR