DTC B1249 Double Locking ECU Communication Stop |
| DTC No. | DTC Detection Condition | Trouble Area |
| B1249 | Communication between double lock door control relay assembly and main body ECU interrupted for 10 seconds or more, or communication wire malfunction. |
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| 1.CLEAR DTC |
Clear DTCs (Click here).
| NEXT | |
| 2.CHECK FOR DTC |
Check for DTCs (Click here).
| Result | Proceed to |
| DTC B1249 is output | A |
| DTC B1249 and B2325 are output | B |
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| A | |
| 3.CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL J/B - DOUBLE LOCK DOOR RELAY) |
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Disconnect the 3C instrument panel junction block assembly connector.
Disconnect the D40 double lock door control relay assembly connector.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
| 3C-27 (LIN2) - D40-9 (MPX1) | Always | Below 1 Ω |
| D40-9 (MPX1) - Body ground | Always | 10 kΩ or higher |
Measure the voltage according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
| D40-9 (MPX1) - Body ground | Always | Below 0.5 V |
| *1 | Front view of wire harness connector (to Instrument Panel Junction Block Assembly) |
| *2 | Front view of wire harness connector (to Double Lock Door Control Relay Assembly) |
Reconnect the instrument panel junction block assembly connector.
Reconnect the double lock door control relay assembly connector.
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| OK | |
| 4.CHECK HARNESS AND CONNECTOR (DOUBLE LOCK DOOR RELAY - BATTERY AND BODY GROUND) |
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Disconnect the D40 double lock door control relay assembly connector.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
| D40-14 (GND) - Body ground | Always | Below 1 Ω |
Measure the voltage according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
| D40-1 (+B) - Body ground | Always | 11 to 14 V |
| *1 | Front view of wire harness connector (to Double Lock Door Control Relay Assembly) |
Reconnect the double lock door control relay assembly connector.
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| OK | |
| 5.REPLACE DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY NORMAL ONE |
Replace the double lock door control relay assembly with a normally functioning part (Click here).
Clear DTCs (Click here).
| NEXT | |
| 6.RECONFIRM DTC OUTPUT |
Recheck for DTCs (Click here).
| Result | Proceed to |
| DTC B1249 is not output | A |
| DTC B1249 is output | B |
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| A | ||
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| 7.INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY |

| *1 | Component without harness connected (Instrument Panel Junction Block Assembly) |
Remove the instrument panel junction block assembly (Click here).
Remove the main body ECU from instrument panel junction block assembly (Click here).
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
| 3C-27 (LIN2) - 3F-16 (LIN2) | Always | Below 1 Ω |
| 3C-27 (LIN2) - Body ground | Always | 10 kΩ or higher |
Reinstall the main body ECU (Click here).
Reinstall the instrument panel junction block assembly (Click here).
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| OK | ||
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