Powertrain
generic / SAE
P28C4
Clutch A Phase U-V-W Circuit Low
The output stage for the clutch A BLDC motor reports a low phase voltage on at least one of the U/V/W phases. Short to ground or interrupted half-bridge.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number8 / C4
Possible causes
- Phase wire shorted to ground high
- Low-side switch open in driver medium
- Connector pins corroded - high contact resistance low
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 500–2800 €
- Estimated time: 3–10 h
- Component: clutch motor a
- Component: wiring harness
- Component: tcm
- MIL / check engine light
- limp mode possible
Sources
References
sae:J2012