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Code: U0146 - Lost Communication With Serial Data Gateway Module 'A'

Posted: Thu Jan 01, 2026 5:37 pm
by Adrian_556
I updated the firmware in the IPC Mondeo mk5 2015 everything went ok and everything working but now have a DTC that will not clear

Code: U0146 - Lost Communication With Serial Data Gateway Module 'A'

Status (-28):
- Previously Set DTC - Not Present at Time of Request
- Malfunction Indicator Lamp is Off for this DTC

Module: Transmission Control Module

Freeze Frame #1:
-EVENT_TIME: 342650643 s (Thu Jan 01 12:06:04 2026) - Event time
-MODULE_VOLTAGE: 11.3 V - Control Module Voltage

Battery is ok tried disconnecting to 10 minutes but still wont clear the DTC time 12:06 is when forscan was erasing block 2/2 in the ECU: JST-14C026-AJB. I re-flashed the old firmware still have the same DTC. any help appreciated. I did connect a battery charger part way through the update could this have caused the problem.

Re: Code: U0146 - Lost Communication With Serial Data Gateway Module 'A'

Posted: Sat Jan 03, 2026 12:21 pm
by boosted_diesel
The fact the battery was down to 11.3v and you were flashing a module might have something to do with it. Voltage must always be maintained when programming.
If 11.3v is the voltage of your battery when it’s charged then you need a new battery just for starters.