OBD-II code · Powertrain (generic)
P0943 Hydraulic Pressure Unit Cycling Period Too Short
The hydraulic pressure unit cycles on/off too frequently. Indicates internal leakage or pressure regulation drift.
Is it safe to drive with P0943?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyInternal hydraulic leak
- PossiblePressure regulator drifted
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
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 2–8 h
- Emissions test
- Usually unaffected
- Parts involved
- Hydraulic Pressure Unit, Pressure Regulator
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.