DTC B279A Theft Deterrent System Communication Line High Fixation |
| DTC No. | DTC Detection Condition | Trouble Area |
| B279A | When communication line (EFIO-IMI) between ECM and transponder key ECU is stuck on HI output for 6 seconds or more |
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| 1.CHECK FOR DTC |
Check for DTCs (Click here).
| Result | Proceed to |
| DTC B279A is output | A |
| DTC B279A and other DTCs are output | B |
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| A | |
| 2.CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - ECM) |
Disconnect the D29 transponder key ECU connector.

| *1 | Front view of wire harness connector (to Transponder Key ECU) | *2 | Front view of wire harness connector (to ECM) |
| *3 | for 1KR-FE and 1NR-FE | *4 | for 1ND-TV |
Disconnect the A18 or A19 ECM connector.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
| D29-13 (EFIO) - A19*1-77 (IMI) | Always | Below 1 Ω |
| D29-13 (EFIO) - A18*2-11 (IMI) | Always | Below 1 Ω |
| D29-13 (EFIO) or A19*1-77 (IMI) - Body ground | Always | 10 kΩ or higher |
| D29-13 (EFIO) or A18*2-11 (IMI) - Body ground | Always | 10 kΩ or higher |
Measure the voltage according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
| D29-13 (EFIO) - Body ground | Always | Below 1 V |
| A19*1-77 (IMI) - Body ground | Always | Below 1 V |
| A18*2-11 (IMI) - Body ground | Always | Below 1 V |
Reconnect the ECU and ECM connector.
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| OK | |
| 3.INSPECT TRANSPONDER KEY ECU (OUTPUT) |
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Measure the waveform.
| Terminal No. (Symbol) | Tool Setting | Switch Condition |
| D29-13 (EFIO) - D29-16 (GND) | 10 V/DIV., 500 msec./DIV. | Ignition switch ON |
| Result | Proceed to |
| Waveform is not output normally | A |
| Waveform is output normally (for 1ND-TV) | B |
| Waveform is output normally (for 1KR-FE) | C |
| Waveform is output normally (for 1NR-FE) | D |
| *1 | Component with harness connected (Transponder Key ECU) |
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| A | |
| 4.INSPECT TRANSPONDER KEY ECU (POWER SOURCE AND BODY GROUND) |
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Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
| Tester Connection | Switch Condition | Specified Condition |
| D29-1 (+B) - D29-16 (GND) | Ignition switch ON | 11 to 14 V |
| *1 | Component with harness connected (Transponder Key ECU) |
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| OK | ||
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