P0748 is a generic pressure-control solenoid electrical fault label. An enquiry should preserve that wording instead of reducing it to “low gearbox pressure”. The code description and any measured pressure are separate pieces of evidence.
Identify the transmission first
Send the gearbox code and controller identification from the diagnostic report. A model badge may cover several transmission types. Photographs of an externally accessible label, or identification already recorded by the garage, are preferable to an online listing that merely resembles the unit.
Keep two parts of the report
For the operating symptoms, describe harsh engagement, missing gears, limp mode or the actual warning. For the electrical investigation, include the circuit named by the manufacturer, the tests completed and whether the fault was active during them. If a hydraulic assessment has also been performed, include it as a separate section with its conditions.
This separation makes a referral more useful. It prevents a genuine circuit finding from being lost among general gearbox complaints, while also preventing an electrical code from being treated as proof that the mechanical transmission is sound.
Before sending a TCU
Contact AXION with the full report, original module number and previous repair history. Agree what the removed electronics assessment can answer and which checks still require the vehicle. Do not buy a donor based on P0748 alone or apply generic solenoid resistance figures from another gearbox.
Definition reference HELLA generic powertrain code list. The precise circuit and repair procedure are vehicle-specific.
Use the full fault description from your scan and the repair information for your vehicle.