P0750–P0770 Shift Solenoid A

Which code is which

Same fault, different cylinder or bank — diagnosed the same way. Several set together usually means one shared cause.

The definition

P0750: Shift Solenoid A.

P0750 is a powertrain code (the engine or gearbox), defined by the SAE standard - it means the same thing on any make of car, and any generic OBD-II reader will decode it.

What to check first

Cheapest and fastest checks first:

1. Read the freeze-frame data stored with the fault - engine speed, load and temperature at the moment it logged tell you whether this happens cold, hot or under load.
2. Check the connector at the part for corrosion, and that it is fully seated.
3. Clear the code and see whether it returns, and under what conditions.

What actually causes this on a VAG

An automatic gearbox picks gears by routing oil pressure to different clutch packs, and small electrically operated valves called shift solenoids do the switching. P0750 is the general 'shift solenoid A malfunction' code. That word general matters: the code says the gearbox control unit is unhappy with that solenoid, but it does not say whether the problem is electrical or hydraulic. The neighbouring codes are the ones that say - P0751 is stuck off or under-performing, P0752 is stuck on, P0753 is a genuine electrical circuit fault, and P0754 is the same complaint coming and going. If P0750 is all you have, read it as 'something is wrong with shift solenoid A', not as proof the solenoid has died. You will usually feel it as harsh, delayed or missing shifts, or the car dropping into limp mode where it holds a single gear and lights the gearbox warning. One more thing worth knowing before anyone starts spending: 'A' is generic OBD-II naming. VAG does not label its gearbox solenoids A, B and C - a VAG-aware scan tool will name them Solenoid Valve 1, Solenoid Valve 2 and so on, which is what a workshop actually needs in order to know which valve is being complained about. A generic code reader cannot tell you that, which is a good reason not to let one drive the repair.

Most likely causes, in order

1. Wiring or connector where the loom enters the gearbox. The solenoids live inside the box and the harness passes through a sealed plug on the casing. That plug and the wiring around it take heat, vibration and oil, and on many gearboxes automatic transmission fluid can creep along the inside of the wires and corrode the pins. Inspect the connector for oil, green corrosion or chafed wires before anything else - it is by far the cheapest thing on this list, and it is a repair rather than a parts bill.
2. Low, old or contaminated gearbox oil. Solenoids and their valve bores rely on clean fluid at the right level and pressure. Fluid that is overdue, burnt-smelling or low leaves valves sticky and pressures out of range, which the control unit can log as a solenoid fault. Have the level and condition checked properly: most modern VAG automatics have no dipstick at all, the level is set at an overflow plug from underneath, and it is only correct within a narrow fluid-temperature window specified for that gearbox. A guess at the level tells you nothing.
3. Poor battery or charging voltage. Solenoid circuits are monitored for current and voltage, and a tired battery or a charging fault can make the control unit see figures it considers impossible. Testing the battery under load and checking the charging output costs nothing and takes minutes, so do it before anything is dismantled - particularly if the code appeared alongside other odd electrical behaviour or a crop of unrelated codes.
4. The solenoid, valve body or mechatronic unit. Coils go open circuit or short, and valve bores wear. On many VAG gearboxes the solenoids are part of the valve body or mechatronic unit and are not sold as individual parts, so the repair is that whole assembly. This is the expensive answer, and it should only be reached after the wiring, the fluid and the supply voltage have been cleared, and after the gearbox control unit's own fault memory and live data have been read - not just a generic OBD scan of the engine.

Worth knowing: Do not accept a quote for a replacement gearbox on this code alone. The solenoids sit in the valve body or mechatronic unit, which is normally a serviceable assembly in its own right, and a large share of these faults turn out to be the external plug, the loom, the fluid or the battery. Ask for the gearbox control unit's own fault memory and live values, and ask which solenoid valve number the tool is naming. Also say which gearbox is fitted when you ring round - a torque-converter automatic, a DSG or S tronic, and a multitronic CVT share almost nothing in parts or in repair cost, and a quote given without that is a guess.

Common questions

What does P0750 mean?

P0750 means Shift Solenoid A. It is logged when the ECU sees this circuit outside its expected operating window.

Can I drive with P0750?

The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.

Related reading

• DSG juddering or jerking: what's normal and what isn't
• DQ200 7-Speed Dry DSG: Problems and What to Check
• DQ250 6-Speed Wet DSG: Problems, Servicing and Buying Checks
• DQ500 & DL501 S tronic: Problems, Servicing, What to Check
• Why the same fault code has completely different causes