Trans line pressure issue.
P0796 — also written PO796, P 0796, 0796 — is the OBD-II code for pressure control solenoid 'c' performance. Same code, same fix: this page covers every spelling of it.
Your gearbox brain is trying to move a shift valve but isn't seeing the pressure it expects. Usually, it's a sign of a tired Vauxhall 6T40 box or a Ford Powershift starting to eat itself.
P0796 is a transmission fault code, typically costing £150–£1500 to put right in a UK garage.
What P0796 actually feels like to drive
- The car 'thumps' into gear like you've been rear-ended when pulling away from lights.
- Engine revs flare up between 2nd and 3rd gear, then it bangs into gear (flaring).
- Loss of drive entirely after the car gets up to operating temperature.
- 'Transmission Service Required' message on the dash followed by Limp Mode (locked in 3rd).
- Gearbox stays in a high gear when you're slowing down, nearly stalling the engine.
What causes P0796?
- Worn pump
- Solenoid
- Fluid low
UK vehicles that throw P0796 most often
- Vauxhall Astra J/K 1.4 & 1.6 Turbo (6T40/6T45 auto) 2010-2018
- Ford Mondeo Mk4/Mk5 2.0 TDCi (6DCT450 Powershift) 2010-2016
- Volvo V40/V60 2.0 D3/D4 (Aisin-Warner TF-80SC) 2012-2017
- Vauxhall Insignia A 2.0 CDTi (A20DTH/A20DT) 2008-2017
- Chevrolet Cruze 1.6/1.8 Petrol (6T40 Transmission) 2009-2015
- Nissan Qashqai J11 1.6 dCi (Xtronic CVT variants) 2014-2018
How P0796 is fixed
- Fluid service
- Solenoid replacement
The P0796 misdiagnosis that wastes money
I see folks reflexively chucking a £400 solenoid at the valve body before they’ve even pulled the dipstick. Nine times out of ten on high-mileage Vauxhalls or Fords, P0796 isn't a dead electrical coil; it’s 'debris-in-the-blood'. Tiny metal shavings from a wearing pump or a failing torque converter clog the solenoid's tiny ports. If you replace the part without flushing the box and checking for 'glitter' in the oil, the new solenoid will jam up within a fortnight. Inspect the fluid first—it tells the whole story.
What a UK garage should charge for P0796
A basic diagnostic scan is £60-£90. A proper fluid and filter service using quality Motul or Castrol Transmax will run you £180-£300. If we have to drop the pan and swap a solenoid, you're looking at £450-£600 including the VAT and fresh fluid. The 'big one' is if the pump has internal wear or the clutch packs are burnt—that’s a full rebuild job, and you won't see change from £1,500-£2,200 at a UK specialist. Stick to ZF or LuK components if you can.
P0796 repair cost in the UK
Most P0796 repairs land between £150–£1500 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Bob's tip on P0796
If your local garage says 'you need a new gearbox' for £3k without even doing a pressure test, walk away. Insist on a 'line pressure test' while the car is running. It’ll tell us if the pump is actually making pressure or if Solenoid C is just being a lazy bugger. Also, ask for a 'gearbox adaptation reset' after any fluid work. These modern 6-speed units learn your driving style, and if the fluid was filthy, the computer needs to 'unlearn' the bad habits it picked up while compensating for the old sludge.
Can you drive with P0796?
Limp mode.
Urgency: high.