Oil Pressure Optimizations — oil pressure fix and clutch pressure

Oil Pressure Optimizations does two different jobs depending on whose file it is. In a gearbox (TCU) file it is the pressure that lets the clutches hold the extra torque after tuning. In an engine file (Bosch MD1 on VAG diesels and other ECUs) it is an oil pressure fix: the ECU keeps higher pressure in the lubrication system where the stock calibration lowers it. For tuners: send us the original file and get a ready-to-flash file with corrected checksums, on average in 30–60 minutes.

Gearbox: how the TCU sets clutch pressure

A clutch holds torque by clamping its plates together, and oil pressure provides the clamping force. That pressure is not fixed: the TCU calculates it from the torque the engine ECU reports. More torque means more pressure, within the limits of the calibration. Wet DSG units and torque-converter automatics both work this way: on the DQ250 the clutch pressures are set from ECU torque, on the ZF 6HP and 8HP it is the hydraulic pressure inside the gearbox.

Slip control runs on top of that calculation. On the DQ250 the stock logic keeps pressure at the minimum that stops the clutch from slipping, and adds pressure if slip does appear. It only goes up to the ceiling set in the factory calibration, though.

Gearbox: why clutches slip after a remap

After Stage 1 or Stage 2 the torque goes beyond what the stock pressures were designed for. Shifts become soft and slow first, then the clutches start to slip and heat up, and the gearbox throws overheating warnings. With low fluid level this happens sooner. The same thing happens if torque is understated in the engine file to get around the gearbox limit: the TCU calculates pressure from the understated figure. How to remove the limits themselves properly is covered on the Torque Unlock page.

Gearbox: what changes in the TCU file

Engine: how the ECU controls oil pressure

Many modern engines have a variable oil pump, with the ECU controlling the pressure in the lubrication system. Take the VW EA288 diesels. The pump is a vane pump with a rotating adjustment ring, and it runs on two pressure stages. The ECU picks the stage from load, engine speed and oil temperature and switches it with the N428 valve. At light load the pressure is about 1.8–2.0 bar; at high load or engine speed, for example at full-throttle acceleration, it is 3.8–4.2 bar. The low stage is there to save energy: the pump takes less power in town driving.

Engine: what the oil pressure fix solves

Workshops that offer this fix describe the same picture. On a number of VAG engines the oil pressure at idle and low engine speed is lowered in software, for emissions and economy. The engines they name are the second-generation 3.0 TDI EA897, the 4.0 TDI EA898, the 2.0 TDI EA288 Evo, the 2.9 and 3.0 TFSI EA839 and the second-generation EA896 TDI.

According to them, the pressure margin is eaten up by diluted oil (DPF regenerations, short trips) and long service intervals. The oil pressure warning then comes on at hot idle, while the bearings, the turbocharger and the timing chain drive run on minimal lubrication.

The fix raises the target oil pressure at idle and low engine speed, with no mechanical changes. The cost is a little more power to drive the pump, which is exactly what the low stage was designed to save. Bosch MD1 units, used on the 2.0 TDI EA288 and EA288 Evo, are one example. Our database also has the option for Delphi CRD and DCM, Bosch EDC17, Continental SID and Marelli MJD: whether the fix is available for a specific ECU is clear from its file.

Engine: VAG oil pressure fault codes

If the ECU already logs oil pressure faults, find the cause first. The fix does not clear them and does not cure the fault.

VAG manufacturer codes, meanings per VW service information and owners' diagnostic logs. Other makes use their own codes for the same faults.

How to order the file

1. Read the original file of the gearbox or engine unit via OBD or on the bench with the tool you use. We need an unmodified stock file.
2. Upload it to the portal and select OIL PRESSURE OPTIMIZATIONS. For a gearbox, give the Stage and engine torque in the comment, and add TORQUE UNLOCK if needed. For an engine, give the engine code and any oil pressure faults.
3. Get the finished file with recalculated checksums, on average within 30–60 minutes.
4. Flash the file. On a gearbox, reset the adaptations and check the shifts under load. On an engine, clear the faults and make sure the oil pressure warning does not come back.

If the engine is not tuned yet, the engine file can be ordered too: Stage 1 or Stage 2.