P073A — Gear 1 — incorrect ratio
Reference detail for fault code P073A on the DQ500 DSG transmission family.
What P073A indicates
The DQ500 transmission control unit stores P073A when it detects the following condition: Gear 1 — incorrect ratio. This is a mechanical plausibility check: the control unit compares the input and output shaft speeds with the ratio expected for the selected gear. The code is stored when the calculated ratio does not match or a gear drops out unexpectedly. A stored code does not by itself prove that a part has failed. Before replacing anything, check the live data, wiring, connectors, power supply and fluid condition, and confirm the fault on the vehicle.
Symptoms
- Engine revs flare without acceleration
- Gear drops out or the transmission stays in one gear
- Emergency mode
- Transmission warning light
Possible causes
- Clutch slip
- Gear disengaging because of a gear selector or shift fork fault
- Faulty input or output speed sensor
- Internal mechanical damage (gears, synchronisers, bearings)
Related components
Speed sensors · Gear selector / shift fork · Dual clutch · Gear set
| Fault code | P073A |
|---|---|
| Transmission | DQ500 (7-speed wet DSG) |
| Factory code | 0BH/0BT |
| Category | Gear ratio / gear loss |
| Status | Documented — review advised |
This code is documented but not independently confirmed. Confirm it against the specific vehicle before ordering any part.
Have this code on your vehicle?
Send us the code and the vehicle details and we will confirm the correct unit or part by email.
Related pages for the DQ500
DQ500 repair
Symptoms, mechatronic issues and what repair involves for this family.
DQ500 mechatronics
Replacement mechatronic unit and exchange options for this family.
DQ500 parts
Selected parts most often involved in repair for this family.
DQ500 fault codes
Every documented code for this family in one table.
Have a fault code to check?
Send us the code and the vehicle details and we will confirm the correct unit or part by email.