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*):
·
A malfunction is detected in the communication or communication lines between the ECM and ID code box (immobiliser code ECU). ·
The communication ID codes of the ECM and ID code box (immobiliser code ECU) do not match. |
·
ID code box (immobiliser code ECU) ·
ECM ·
Harness or connector |
DTC output confirmation operation (Perform either of the following):
·
Start the engine and wait for 10 seconds. If there is a malfunction, the engine will stop (communication begins within 3 seconds of the engine start operation being performed, and DTCs are stored after 6 seconds). ·
Connect the cable to the negative (-) auxiliary battery terminal, start the engine and wait for 10 seconds (communication begins within 3 seconds of the ignition switch being turned to ON, and DTCs are stored after 6 seconds). |
*: Only output while a malfunction is present.
| Vehicle Condition when Malfunction Detected | Fail-safe Operation when Malfunction Detected |
|---|---|
| Engine cannot be started | - |
| DTC No. | Data List and Active Test |
|---|---|
| B279986 | - |
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 / Smart Key. 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 entry and start 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 entry and start system (for Start Function) after confirming that the communication systems are functioning properly.
Before replacing the ECM or ID code box (immobiliser code ECU), refer to Service Bulletin.
After performing repairs, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".
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.
Register the ECU communication ID code.
Refer to Service Bulletin.
| Proceed to |
|---|
| NEXT |
NEXT
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. |
| Tester Connection | Condition | Tool Setting | Specified Condition |
|---|---|---|---|
| G57-3 (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 |
A
B
C
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. |
| Tester Connection | Condition | Tool Setting | Specified Condition |
|---|---|---|---|
| G57-4 (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) |
| Proceed to |
|---|
| OK |
| NG |
OK
NG
Register the ECU communication ID codes.
Refer to Service Bulletin.
| Proceed to |
|---|
| NEXT |
NEXT
Using an electrical key transmitter sub-assembly which is registered to the vehicle, turn the ignition switch to ON.
Check that the engine can be started 5 seconds after the ignition switch turned to ON.
Engine starts normally.
| Proceed to |
|---|
| OK |
| NG |
OK
NG
for M20C-FKS:
for M20D-FKS:
Disconnect the G57 ID code box (immobiliser code ECU) connector.
Disconnect the A125*1 or A116*2 ECM connector.
*1: for GTMC Made
*2: for SFTM Made
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| G57-4 (EFIO) - A125-54 (IMI) | Always | Below 1 Ω |
| G57-4 (EFIO) or A125-54 (IMI) - Other terminals and body ground | Always | 10 kΩ or higher |
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| G57-4 (EFIO) - A116-54 (IMI) | Always | Below 1 Ω |
| G57-4 (EFIO) or A116-54 (IMI) - Other terminals and body ground | Always | 10 kΩ or higher |
| Proceed to |
|---|
| OK |
| NG |
OK
NG
Disconnect the A125*1 or A116*2 ECM connector.
*1: for GTMC Made
*2: for SFTM Made
Measure the voltage according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A125-55 (IMO) - Body ground | Ignition switch turned to ON using registered electrical key transmitter sub-assembly | Terminal IMO stuck low (2.4 V or less) |
| Terminal IMO stuck high (12 V) or abnormal waveform |
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A116-55 (IMO) - Body ground | Ignition switch turned to ON using registered electrical key transmitter sub-assembly | Terminal IMO stuck low (2.4 V or less) |
| 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 |
A
B
for M20C-FKS:
for M20D-FKS:
Disconnect the G57 ID code box (immobiliser code ECU) connector.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| G57-3 (EFII) - A125-55 (IMO) | Always | Below 1 Ω |
| G57-3 (EFII) or A125-55 (IMO) - Other terminals and body ground | Always | 10 kΩ or higher |
| G57-4 (EFIO) - A125-54 (IMI) | Always | Below 1 Ω |
| G57-4 (EFIO) or A125-54 (IMI) - Other terminals and body ground | Always | 10 kΩ or higher |
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| G57-3 (EFII) - A116-55 (IMO) | Always | Below 1 Ω |
| G57-3 (EFII) or A116-55 (IMO) - Other terminals and body ground | Always | 10 kΩ or higher |
| G57-4 (EFIO) - A116-54 (IMI) | Always | Below 1 Ω |
| G57-4 (EFIO) or A116-54 (IMI) - Other terminals and body ground | Always | 10 kΩ or higher |
| Proceed to |
|---|
| OK |
| NG |
OK
NG
Disconnect the G57 ID code box (immobiliser code ECU) connector.
Disconnect the A125*1 or A116*2 ECM connector.
*1: for GTMC Made
*2: for SFTM Made
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| G57-3 (EFII) - A125-55 (IMO) | Always | Below 1 Ω |
| G57-3 (EFII) or A125-55 (IMO) - Other terminals and body ground | Always | 10 kΩ or higher |
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| G57-3 (EFII) - A116-55 (IMO) | Always | Below 1 Ω |
| G57-3 (EFII) or A116-55 (IMO) - Other terminals and body ground | Always | 10 kΩ or higher |
| Proceed to |
|---|
| OK |
| NG |
OK
for M20C-FKS:
for M20D-FKS:
NG