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U139400 — Clock synchronization master, branch 5, invalid number
Clock synchronization master, branch 5, invalid number. The Taycan, 911 (992), Panamera (971), Panamera (972) and Cayenne report this code; below is which control unit sets it on each model and how to read and clear it.
Which models and control units set U139400
How to read and clear U139400
- Plug a standard ENET (Ethernet-to-OBD) cable into your Porsche's OBD port and your Mac or Windows PC.
- Open STEUER14, pick your car and run a fault scan: every control unit is read, and U139400 shows with its status, its full description and the freeze frame when the unit stores one.
- Fix the cause first, then clear the fault memory and scan again to check it stays away. Reading and clearing fault codes is free on every control unit.
More about fault memory in the manual →
Download STEUER14 — free fault readingOther codes of the Gateway
| U133E00 | LIN bus, steering wheel touch recognition - no communication |
| U138F00 | Clock synchronization failure |
| U139000 | Clock synchronization master, branch 1, invalid number |
| U139100 | Clock synchronization master, branch 2, invalid number |
| U139200 | Clock synchronization master, branch 3, invalid number |
| U139300 | Clock synchronization master, branch 4, invalid number |
| U139500 | Clock synchronization master, branch 6, invalid number |
| U139600 | Clock synchronization master, branch 7, invalid number |
| U139700 | Clock synchronization master, branch 8, invalid number |
| U139B00 | Laser scanner - no communication |
| U13BE00 | Front sensors for driver assistance systems, Private CAN bus - no communication |
| U13BF00 | Brake electronics control module, no communication at the second bus connection |
All 374 codes of this control unit →
Fault names come from the manufacturer's diagnostic data. STEUER14 is independent and not affiliated with Porsche AG. A code tells you what a control unit detected, not always which part failed — check wiring, supply voltage and related codes before replacing parts. STEUER14 shows each fault's full description, status and freeze frame on the car.