| Last Modified: 05-13-2024 | 6.11:8.1.0 | Doc ID: RM100000002BENJ |
| Model Year Start: 2023 | Model: GR Corolla | Prod Date Range: [03/2023 - ] |
| Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): B279986; Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid; 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [03/2023 - ] | ||
|
DTC |
B279986 |
Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid |
DESCRIPTION
If there is a communication malfunction between the ECM and ID code box (immobiliser code ECU), or when the communication ID codes do not match, the ECM stores this DTC.
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
Note |
|---|---|---|---|---|
|
B279986 |
Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid |
Either of the following conditions is met (1 trip detection logic*):
|
|
DTC output confirmation operation (Perform either of the following):
|
- *: Only output while a malfunction is present.
Vehicle Condition and Fail-safe Operation when Malfunction Detected
|
Vehicle Condition when Malfunction Detected |
Fail-safe Operation when Malfunction Detected |
|---|---|
|
Engine cannot be started |
- |
Related Data List and Active Test
|
DTC No. |
Data List and Active Test |
|---|---|
|
B279986 |
- |
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
-
When using the GTS with the ignition switch off, connect the GTS to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the GTS and the vehicle begins.
Then select Model Code "KEY REGIST" under manual mode and enter the following menus: Body Electrical / Start Key(CAN). While using the GTS, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the GTS and the vehicle.
-
The smart key system (for Start Function) uses the LIN communication system and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the smart key system (for Start Function) after confirming that the communication systems are functioning properly.
Click here
![2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [11/2022 - ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): HOW TO PROCEED WITH TROUBLESHOOTING](/t3Portal/stylegraphics/info.gif)
-
Before replacing the ECM or ID code box (immobiliser code ECU), refer to Registration.
Click here
- After performing repairs, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".
HINT:
When DTC B279986 and the certification ECU (smart key ECU assembly) DTC are output simultaneously, first perform troubleshooting for the certification ECU (smart key ECU assembly) DTC.
PROCEDURE
|
1. |
REGISTER ECU COMMUNICATION ID |
(a) Register the ECU communication ID code.
Click here
|
|
2. |
CHECK ID CODE BOX (IMMOBILISER CODE ECU) (TERMINAL EFII) |
(a) Using an oscilloscope, check the waveform.
|
*a |
Component with harness connected (ID Code Box (Immobiliser Code ECU)) |
*b |
Waveform |
|
*c |
Approximately 160 ms. |
*d |
Approximately 270 ms. |
OK:
|
Tester Connection |
Condition |
Tool Setting |
Specified Condition |
|---|---|---|---|
|
I20-3 (EFII) - Body ground |
Within 3 seconds of the engine start operation being performed or within 3 seconds of the ignition switch being turned to ON after connecting the cable to the negative (-) auxiliary battery terminal |
2 V/DIV., 500 ms./DIV. |
Pulse generation (See waveform) |
|
Result |
Proceed to |
|---|---|
|
Normal waveform |
A |
|
Terminal EFII stuck low (2.4 V or less) |
B |
|
Waveform not output, or has abnormal wavelength or shape, or terminal EFII stuck high (12 V) |
C |
| B |
|
| C |
|
|
|
3. |
CHECK ID CODE BOX (IMMOBILISER CODE ECU) (TERMINAL EFIO) |
(a) Using an oscilloscope, check the waveform.
|
*a |
Component with harness connected (ID Code Box (Immobiliser Code ECU)) |
*b |
Waveform |
|
*c |
Approximately 160 ms. |
*d |
Approximately 270 ms. |
Measurement Condition:
|
Tester Connection |
Condition |
Tool Setting |
Specified Condition |
|---|---|---|---|
|
I20-4 (EFIO) - Body ground |
Within 3 seconds of the engine start operation being performed or within 3 seconds of the ignition switch being turned to ON after connecting the cable to the negative (-) auxiliary battery terminal |
2 V/DIV., 500 ms./DIV. |
Pulse generation (See waveform) |
| NG |
|
|
|
4. |
REGISTER ECU COMMUNICATION ID (ID CODE BOX (IMMOBILISER CODE ECU) - ECM) |
(a) Register the ECU communication ID codes.
Click here
|
|
5. |
CHECK WHETHER ENGINE STARTS |
Pre-procedure1
(a) Using an electrical key transmitter sub-assembly which is registered to the vehicle, turn the ignition switch to ON.
Procedure1
(b) Check that the engine can be started 5 seconds after the ignition switch turned to ON.
OK:
Engine starts normally.
Post-procedure1
(c) None
| OK |
|
END (ECU COMMUNICATION ID HAS NOT BEEN REGISTERED) |
| NG |
|
REPLACE ECM for M20A-FKS: Click here
for G16E-GTS: Click here
|
|
6. |
CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - ECM) |
Pre-procedure1
(a) Disconnect the I20 ID code box (immobiliser code ECU) connector.
(b) Disconnect the A47*1, A178*2 or A139*3 ECM connector.
- *1: for M20A-FKS (except K121 CVT)
- *2: for M20A-FKS (K121 CVT)
- *3: for G16E-GTS
Procedure1
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
for M20A-FKS (except K121 CVT):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I20-4 (EFIO) - A47-26 (IMI) |
Always |
Below 1 Ω |
|
I20-4 (EFIO) or A47-26 (IMI) - Other terminals and body ground |
Always |
10 kΩ or higher |
for M20A-FKS (K121 CVT):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I20-4 (EFIO) - A178-54 (IMI) |
Always |
Below 1 Ω |
|
I20-4 (EFIO) or A178-54 (IMI) - Other terminals and body ground |
Always |
10 kΩ or higher |
for G16E-GTS:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I20-4 (EFIO) - A139-61 (IMI) |
Always |
Below 1 Ω |
|
I20-4 (EFIO) or A139-61 (IMI) - Other terminals and body ground |
Always |
10 kΩ or higher |
Post-procedure1
(d) None
| OK |
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
7. |
CHECK ECM |
Pre-procedure1
(a) Disconnect the A47*1, A178*2 or A139*3 ECM connector.
- *1: for M20A-FKS (except K121 CVT)
- *2: for M20A-FKS (K121 CVT)
- *3: for G16E-GTS
Procedure1
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
for M20A-FKS (except K121 CVT):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A47-25 (IMO) - Body ground |
Ignition switch turned to ON using registered electrical key transmitter sub-assembly |
Terminal IMO stuck low (2.4 V or less) |
|
Terminal IMO stuck high (12 V) or abnormal waveform |
for M20A-FKS (K121 CVT):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A178-55 (IMO) - Body ground |
Ignition switch turned to ON using registered electrical key transmitter sub-assembly |
Terminal IMO stuck low (2.4 V or less) |
for G16E-GTS:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A139-47 (IMO) - Body ground |
Ignition switch turned to ON using registered electrical key transmitter sub-assembly |
Terminal IMO stuck low (2.4 V or less) |
|
Terminal IMO stuck high (12 V) or abnormal waveform |
|
Result |
Proceed to |
|---|---|
|
Terminal IMO stuck low (2.4 V or less) |
A |
|
Terminal IMO stuck high (12 V) or abnormal waveform |
B |
Post-procedure1
(c) None
| B |
|
REPLACE ECM for M20A-FKS: Click here
for G16E-GTS: Click here
|
|
|
8. |
CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - ECM) |
Pre-procedure1
(a) Disconnect the I20 ID code box (immobiliser code ECU) connector.
Procedure1
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
for M20A-FKS (except K121 CVT):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I20-3 (EFII) - A47-25 (IMO) |
Always |
Below 1 Ω |
|
I20-3 (EFII) or A47-25 (IMO) - Other terminals and body ground |
Always |
10 kΩ or higher |
|
I20-4 (EFIO) - A47-26 (IMI) |
Always |
Below 1 Ω |
|
I20-4 (EFIO) or A47-26 (IMI) - Other terminals and body ground |
Always |
10 kΩ or higher |
for M20A-FKS (K121 CVT):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I20-3 (EFII) - A178-55 (IMO) |
Always |
Below 1 Ω |
|
I20-3 (EFII) or A178-55 (IMO) - Other terminals and body ground |
Always |
10 kΩ or higher |
|
I20-4 (EFIO) - A178-54 (IMI) |
Always |
Below 1 Ω |
|
I20-4 (EFIO) or A178-54 (IMI) - Other terminals and body ground |
Always |
10 kΩ or higher |
for G16E-GTS:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I20-3 (EFII) - A139-47 (IMO) |
Always |
Below 1 Ω |
|
I20-3 (EFII) or A139-47 (IMO) - Other terminals and body ground |
Always |
10 kΩ or higher |
|
I20-4 (EFIO) - A139-61 (IMI) |
Always |
Below 1 Ω |
|
I20-4 (EFIO) or A139-61 (IMI) - Other terminals and body ground |
Always |
10 kΩ or higher |
Post-procedure1
(c) None
| OK |
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
9. |
CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - ECM) |
Pre-procedure1
(a) Disconnect the I20 ID code box (immobiliser code ECU) connector.
(b) Disconnect the A47*1, A178*2 or A139*3 ECM connector.
- *1: for M20A-FKS (except K121 CVT)
- *2: for M20A-FKS (K121 CVT)
- *3: for G16E-GTS
Procedure1
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
for M20A-FKS (except K121 CVT):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I20-3 (EFII) - A47-25 (IMO) |
Always |
Below 1 Ω |
|
I20-3 (EFII) or A47-25 (IMO) - Other terminals and body ground |
Always |
10 kΩ or higher |
for M20A-FKS (K121 CVT):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I20-3 (EFII) - A178-55 (IMO) |
Always |
Below 1 Ω |
|
I20-3 (EFII) or A178-55 (IMO) - Other terminals and body ground |
Always |
10 kΩ or higher |
for G16E-GTS:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I20-3 (EFII) - A139-47 (IMO) |
Always |
Below 1 Ω |
|
I20-3 (EFII) or A139-47 (IMO) - Other terminals and body ground |
Always |
10 kΩ or higher |
Post-procedure1
(d) None
| OK |
|
REPLACE ECM for M20A-FKS: Click here
for G16E-GTS: Click here
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|