P0943Hydraulic Pressure Unit Cycling Period Too Short
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- In a hydraulic pressure unit the pump charges an accumulator up to a cut-out pressure and switches off until pressure falls to the cut-in point. By J2012 wording this code means the pump switches on again too soon, so the interval between charging cycles is shorter than expected. Typical reasons are internal leakage across valves or seals, or an accumulator that has lost its gas precharge and stores too little oil. Audi patents describe such accumulator and leakage checks based on charging switch-over times and pressure decay. No manufacturer documents this exact meaning publicly; Ferrari uses P0943 on its DCT for a system pressure command signal that is too high. CARB requires functional checks of transmission outputs. P0942 is the general fault, P0944 the loss of pressure.
- What you may notice
- Pump can be heard switching on unusually often
- Warning light on
- Slower or harsher gear changes
- Likely causes
- LikelyAccumulator has lost its gas precharge
- LikelyInternal leakage at valves, seals or actuator cylinders
- PossibleFaulty pressure switch or pressure sensor giving wrong cut-in point
- RareLow or aerated hydraulic fluid
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €200 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.