DESCRIPTION
If 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 will store this DTC.
DTC No. | Detection Item |
DTC Detection Condition | Trouble Area |
Note |
---|---|---|---|---|
B279A12 |
Engine Immobiliser System Circuit Short to Battery |
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:
|
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 |
---|---|
B279A12 | - |
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
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.
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HINT:
When DTC B279A12 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. |
CHECK CONNECTION OF CONNECTOR |
(a) Turn the ignition 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 |
|
2. |
CHECK HYBRID VEHICLE CONTROL ECU (TERMINAL IMI) |
(a) Using an oscilloscope, check the waveform.
*a | Component with harness connected (Hybrid Vehicle Control ECU) |
*b | Waveform |
*c | Approximately 160 ms. |
*d | Approximately 270 ms. |
OK:
Tester Connection | Condition |
Tool Setting | Specified Condition |
---|---|---|---|
I249-53 (IMI) - Body ground |
Within 3 seconds of hybrid control system start or within 3 seconds of ignition switch turned to ON after cable disconnected and reconnected to auxiliary battery |
2 V/DIV., 500 ms./DIV. |
Pulse generation (See waveform) |
Result | Proceed to |
---|---|
11 to 14 V | A |
Below 1 V |
B |
Normal waveform |
B | REPLACE HYBRID VEHICLE CONTROL ECU |
|
3. |
CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - HYBRID VEHICLE CONTROL ECU) |
(a) Disconnect the I249 hybrid vehicle control ECU connector.
(b) Disconnect the I20 ID code box (immobiliser code ECU) connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition |
Specified Condition |
---|---|---|
I20-4 (EFIO) - I249-53 (IMI) |
Always | Below 1 Ω |
OK | REPLACE ID CODE BOX (IMMOBILISER CODE ECU) |
NG | REPAIR OR REPLACE HARNESS OR CONNECTOR |