B1200 Multiplex network body ECU Communication stops
Diagnostic trouble codes
DESCRIPTION
- This DTC is detected when communication between the instrument panel junction block (multiplex network body ECU) and multiplex network gateway ECU stops for more than 10 seconds.
| DTC No. |
DTC Detection Condition |
Trouble Area |
| B1200 |
Multiplex network body ECU Communication stops |
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WIRING DIAGRAM
INSPECTION PROCEDURE
- HINT:
- When "+B of GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1200, repair the "+B or GND short malfunction of communication bus" DTCs first.
| 1. CHECK OPERATION |
Check if the wireless door lock control function operates normally through the wireless transmitter.
- HINT:
- With this inspection, the multiplex network body ECU CPU can be diagnosed if it works normally or not.
- OK:
- Wireless door lock function operates normally.
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| NG | |
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| 2. INSPECT FUSE (EUC-B No.1) |
Remove the ECU No.1 fuse from the fusible link block.
Measure the resistance of the fuse.
- Standard resistance:
- Below 1 Ω
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| OK | |
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| 3. CHECK WIRE HARNESS (MULTIPLEX NETWORK BODY ECU - BATTERY AND BODY GROUND) |
Disconnect the 1D and 1F instrument panel junction block connectors.
Measure the resistance and voltage of the wire harness side connectors.
- Standard voltage:
Tester Connection
Specified Condition
1D-10 (BECU) - Body ground
10 to 14 V
- Standard resistance:
Tester Connection
Specified Condition
1F-10 (GND1) - Body ground
Below 1 Ω
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| OK | |
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| 4. CHECK RESISTANCE OF COMMUNICATION LINE |
Disconnect the 1E fusible link block connector.
Disconnect the B7 and T9 ECU connectors.
Disconnect the P19 switch connector.
Measure the resistance of the wire harness side connectors.
- Standard resistance:
Tester Connection
Specified Condition
1E-7 (MPX1) - P19-8 (MPX2)
Below 1 Ω
B7-21 (MPX2) - T9-4 (MPX1)
Below 1 Ω
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| OK | ||
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