Lexus NX: Engine Immobiliser System Communication Line High Fixation (B279A-186)
DESCRIPTION
When the communication line (IMI - EFIO) between the hybrid vehicle control ECU and ID code box (immobiliser code ECU) is stuck high, the hybrid vehicle control ECU stores this DTC.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Note |
|---|---|---|---|---|
| B279A-186 | Engine Immobiliser System Communication Line High Fixation | The communication line (IMI - EFIO) between the hybrid vehicle control ECU and ID code box (immobiliser code ECU) is stuck high. (1 trip detection logic*) |
| DTC output confirmation operation:
|
- *: Only output while a malfunction is present.
| Vehicle Condition when Malfunction Detected | Fail-safe Operation when Malfunction Detected |
|---|---|
| Hybrid control system cannot be started | Hybrid control system cannot be started |
| DTC No. | Data List and Active Test |
|---|---|
| B279A-186 | - |
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
- When using the Techstream with the power 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 Access. 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 hybrid vehicle control ECU or ID code box (immobiliser code ECU), refer to Registration.
Click here
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- After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation."
HINT:
When DTC B279A-186 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. | CLEAR DTC |
(a) Clear the DTCs.
Powertrain > Hybrid Control > Clear DTCs
|
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| 2. | CHECK FOR DTC |
(a) Turn the power switch on (IG) and wait 10 seconds.
(b) Check for DTCs.
Powertrain > Hybrid Control > Trouble CodesHINT:
If DTCs other than DTC B279A-186 are output, troubleshoot those DTCs first.
| Result | Proceed to |
|---|---|
| DTC B279A-186 is output | A |
| DTC B279A-186 and other DTCs are output | B |
| B | .gif) | GO TO DIAGNOSTIC TROUBLE CODE CHART |
|
| 3. | CHECK CONNECTION OF CONNECTOR |
(a) Turn the power switch off.
(b) Check that the connectors are properly connected to the hybrid vehicle control ECU and ID code box (immobiliser code ECU).
OK:
Connectors are properly connected.
| NG | | CONNECT CONNECTORS PROPERLY |
|
| 4. | CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - HYBRID VEHICLE CONTROL ECU) |
(a) Disconnect the I26 ID code box (immobiliser code ECU) connector.
(b) Disconnect the I116 hybrid vehicle control ECU connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| I26-4 (EFIO) - I116-22 (IMI) | Always | Below 1 Ω |
| I26-4 (EFIO) or I116-22 (IMI) - Body ground | Always | 10 kΩ or higher |
(d) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| I116-22 (IMI) - Body ground | Always | Below 1 V |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 5. | REPLACE ID CODE BOX (IMMOBILISER CODE ECU) |
(a) Replace the ID code box (immobiliser code ECU) with a new one.
Click here
|
| 6. | REGISTER RECOGNITION CODE |
(a) Register the recognition codes in the ECUs.
Click here
|
| 7. | REGISTER ECU COMMUNICATION ID |
(a) Register the ECU communication ID.
Click here
|
| 8. | CLEAR DTC |
(a) Clear the DTCs.
Powertrain > Hybrid Control > Clear DTCs
|
| 9. | CHECK FOR DTC |
(a) Perform "DTC Output Confirmation Operation" procedure.
(b) Check for DTCs.
Powertrain > Hybrid Control > Trouble CodesOK:
DTC B279A-186 is not output.
| OK | | END (ID CODE BOX (IMMOBILISER CODE ECU) WAS DEFECTIVE) |
| NG | | REPLACE HYBRID VEHICLE CONTROL ECU |
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