TFT reading unreasonably cold.
P0712 — also written PO712, P 0712, 0712 — is the OBD-II code for transmission fluid temp sensor low input. Same code, same fix: this page covers every spelling of it.
P0712 means the car thinks the gearbox oil is freezing cold because the sensor circuit is shorted. We see this constantly on Vauxhall Insignias and high-mileage VW DSGs where the internal loom has degraded.
P0712 is a transmission fault code, typically costing £150–£600 to put right in a UK garage.
What P0712 actually feels like to drive
- The 'spanner light' or 'Cog' light popping up on the dash.
- Gearbox feels 'thumpy' or harsh when shifting from Park to Drive.
- Transmission stays in 'limp mode' (stuck in 3rd gear) to protect itself.
- Torque converter clutch won't engage, so you're revving higher than usual at 70mph.
- Stop/Start system stops working because the car doesn't know the gearbox temp.
What causes P0712?
- Sensor short
- Wiring fault
UK vehicles that throw P0712 most often
- Vauxhall Insignia 2.0 CDTi (AF40 6-Speed) 2009-2015
- Volkswagen Golf Mk6/Mk7 (DQ250 DSG) 2008-2016
- Ford Mondeo 2.0 TDCi (Powershift) 2010-2014
- Land Rover Discovery 3/4 (ZF 6HP/8HP) 2005-2015
- BMW 3 Series E90/F30 (ZF Automatics) 2006-2018
How P0712 is fixed
- Replace sensor
- Repair wiring
The P0712 misdiagnosis that wastes money
I've lost count of how many times I've seen customers come in having already spent £150 on a generic 'gearbox flush' or a brand new battery thinking it was a voltage issue. They assume the 'Low Input' means the battery is weak. In reality, on these modern units, it's almost always a short in the internal wiring harness or the sensor itself sitting in the oil. You're throwing money away on fresh fluid if you don't fix the sensor that's actually causing the computer to think the box is at -40 degrees Celsius.
What a UK garage should charge for P0712
For a basic sensor swap on something like a Vauxhall or Ford, you're looking at £60-£90 for a diagnostic plug-in. The sensor itself (usually Bosch or Febi) is about £40-£80, but the sting is the labour and the fluid. You’ll need a partial fluid top-up or change, usually Valvoline or Fuchs, costing £80. Total bill at an indie garage is usually £250-£400. If it's a DSG and requires the internal wiring loom, you're pushing £600+. A main dealer will easily double these figures.
P0712 repair cost in the UK
Most P0712 repairs land between £150–£600 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 P0712
Before you let a garage talk you into a £3,000 reconditioned gearbox, insist on a live data check. Ask the tech: 'What is the TFT reading on the scan tool?' If it’s pegged at a constant -40°C even after a motorway run, it’s an electrical circuit fault, not a mechanical failure. Also, on Vauxhalls and Fords, check the multi-pin connector on top of the gearbox for green crusty corrosion (corrosion of conformity, we call it). A quick clean with contact cleaner can sometimes save you a £500 bill.
Can you drive with P0712?
Yes.
Urgency: medium.