DESCRIPTION If there is a
communication malfunction between the ECM and certification ECU (smart
key ECU assembly), 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 certification ECU (smart key ECU assembly).
- The communication ID codes of the ECM and certification ECU (smart key ECU assembly) do not match.
|
- Certification ECU (smart key ECU assembly)
- ECM
- Wire 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 (-) battery terminal, start the engine
and wait for 10 seconds (communication begins within 3 seconds of the
engine switch being turned on (IG), and DTCs are stored after 6
seconds).
|
- *: 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 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 the vehicle type under
manual mode and enter the following menus: Body Electrical / Smart Key.
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.
- The smart key system (for Start Function, Gasoline Model) 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, Gasoline Model)
after confirming that the communication systems are functioning
properly.
Click here 
- Before replacing the ECM or certification ECU (smart key ECU assembly), 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
|
NEXT |
 | |
| 2. |
CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (TERMINAL EFII) |
(a) Using an oscilloscope, check the waveform.
|
*a | Component with harness connected
(Certification ECU (Smart Key ECU Assembly)) |
*b | Waveform | |
*c | Approximately 160 ms. |
*d | Approximately 270 ms. |
OK: |
Tester Connection | Condition |
Tool Setting | Specified Condition | |
A10-3 (EFII) - Body ground |
Engine switch on (IG) |
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 |
C |
| B |
 | GO TO STEP 6 |
| C |
| REPLACE ECM |
|
A | |
| |
| 3. |
CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (TERMINAL EFIO) |
(a) Using an oscilloscope, check the waveform.
|
*a | Component with harness connected
(Certification ECU (Smart Key ECU Assembly)) |
*b | Waveform | |
*c | Approximately 160 ms. |
*d | Approximately 270 ms. |
OK: |
Tester Connection | Condition |
Tool Setting | Specified Condition | |
A10-4 (EFIO) - Body ground |
Engine switch turned on (IG) using registered electrical key transmitter sub-assembly |
2 V/DIV., 500 ms./DIV. |
Pulse generation (See waveform) |
| NG |
| REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
|
OK | |
| |
| 4. |
REGISTER ECU COMMUNICATION ID | (a) Register the ECU communication ID code.
Click here
|
NEXT | |
| |
| 5. |
CHECK WHETHER ENGINE STARTS | (a) Using an electrical key transmitter sub-assembly which is registered to the vehicle, turn the engine switch on (IG).
(b) Check that the engine starts 5 seconds after the engine switch turned on (IG).
OK: Engine starts normally.
| OK |
| END (ECU COMMUNICATION ID HAS NOT BEEN REGISTERED) |
| NG |
| REPLACE ECM |
(a) Disconnect the A18 ECM connector.
(b) Measure the voltage according to the value(s) in the table below. Standard Voltage: |
Tester Connection | Condition |
Specified Condition | |
A18-45 (IMO) - Body ground |
Engine switch turned on (IG) 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 |
| B |
| REPLACE ECM |
|
A | |
| |
| 7. |
CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ECM) |
(a) Disconnect the A10 certification ECU (smart key ECU assembly) connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance: |
Tester Connection | Condition |
Specified Condition | |
A10-3 (EFII) - A18-45 (IMO) |
Always | Below 1 Ω | |
A10-3 (EFII) or A18-45 (IMO) - 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 | |
