THEFT DETERRENT / KEYLESS ENTRY SMART ENTRY AND START SYSTEM(for Start Function, Gasoline Model) B279A12 Engine Immobiliser System Circuit Short to Battery
DESCRIPTION
If the communication line (IMI - EFIO) between the ECM and ID code box (immobiliser code ECU) is stuck high, the ECM 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 ECM and ID code box (immobiliser code ECU) is stuck high. (1 trip detection logic*) | ·
ID code box (immobiliser code ECU) ·
ECM ·
Wire harness or connector |
DTC output confirmation operation:
Turn the ignition switch to ON and wait 6 seconds. |
*: Only output while a malfunction is present.
| Vehicle Condition when Malfunction Detected | Fail-safe Operation when Malfunction Detected |
|---|---|
| Engine cannot be started | Engine cannot be started |
| DTC No. | Data List and Active Test |
|---|---|
| B279A12 | - |
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 / 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".
- 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
Turn the ignition switch off.
Check that the connectors are properly connected to the ECM and ID code box (immobiliser code ECU).
- OK:
Connectors are properly connected.
- Result:
Proceed to OK NG
OK
NG
Check that the engine starts.
- OK:
Engine starts normally.
- Result:
Proceed to OK NG
OK
NG
| *a | Component with harness connected
(ID Code Box (Immobiliser Code ECU)) |
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection Condition Specified Condition G57-4 (EFIO) - Body ground Ignition switch ON 11 to 14 V
- Result:
Proceed to OK NG
OK
NG
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 G57-4 (EFIO) - Body ground Within 3 seconds of engine 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 OK NG
OK
for M20C-FKS:
for M20D-FKS:
NG
Disconnect the A125*1 or A116*2 ECM connector.
*1: for GTMC Made
*2: for SFTM Made
Disconnect the G57 ID code box (immobiliser code ECU) connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
for GTMC Made: Tester Connection Condition Specified Condition G57-4 (EFIO) - A125-54 (IMI) Always Below 1 Ω
for SFTM Made: Tester Connection Condition Specified Condition G57-4 (EFIO) - A116-54 (IMI) Always Below 1 Ω
- Result:
Proceed to OK NG
OK
for M20C-FKS:
for M20D-FKS:
NG