U301AControl Module Wake-up Circuit A/Open
- Generic OBD-II code · Network
- How the car detects it
- A wake-up circuit is a separate wire that rouses a sleeping module without bus traffic, for example when a charge cable is plugged in or another controller needs it. U301A reports that line A has lost continuity, so no valid signal reaches the input. Ford's 2019 hybrid OBD summary shows such a line in use: the battery energy control module relies on a hardwired charge wake-up signal before it runs its charging and contactor checks. No manufacturer documents U301A publicly. GM's PIT6198 for 2019–2022 Silverado and Sierra shows the consequence of a lost wake input at the ECM (circuit 5985, about 12 V with the BCM awake): other modules report U0100 and the service engine lamp comes on, with possible shift complaints. An open wake line usually means the module stays asleep or joins late.
- What you may notice
- Module does not respond, other modules report lost communication
- Charging or a function that needs the wake-up does not start
- Likely causes
- LikelyBroken wake-up wire or pushed-out connector pin
- PossibleCorroded or loose contact at the sending or receiving module
- PossibleSending module or charger not driving the wake-up output
- RareBlown fuse in a supply-fed wake circuit
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.