P0794–P2752 Intermediate Shaft Speed Sensor A Circuit Intermittent
The fault comes and goes, which points at a connection that only breaks under vibration, heat or load.
Can you drive it? The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.
Which code is which
Same fault, different cylinder or bank — diagnosed the same way. Several set together usually means one shared cause.
| Code | Definition | Severity |
|---|---|---|
P0794 | Intermediate Shaft Speed Sensor A Circuit Intermittent | Investigate soon |
P2748 | Intermediate Shaft Speed Sensor B Circuit Intermittent | Investigate soon |
P2752 | Intermediate Shaft Speed Sensor C Circuit Intermittent | Investigate soon |
The definition
P0794: Intermediate Shaft Speed Sensor A Circuit Intermittent.
P0794 is a powertrain code (the engine or gearbox), defined by the SAE standard - it means the same thing on any make of car, and any generic OBD-II reader will decode it.
What to check first
Cheapest and fastest checks first:
- Read the freeze-frame data stored with the fault - engine speed, load and temperature at the moment it logged tell you whether this happens cold, hot or under load.
- Check the connector at the part for corrosion, and that it is fully seated.
- Clear the code and see whether it returns, and under what conditions.
What actually causes this on a VAG
Automatic and DSG gearboxes count shaft speeds at several points so the control module knows exactly what the clutches are doing. This code says one of those intermediate shaft speed signals keeps dropping out momentarily, rather than being permanently dead - the word that matters here is "intermittent". Typically you will get an occasional hard jolt, or a flare between gears (the revs flying up for a moment as the change slips through), or a brief limp mode that clears itself when you stop and restart, with everything feeling completely normal the rest of the time.
Most likely causes, in order
- Wiring or the gearbox connector. Intermittent faults on a box that otherwise behaves are wiring far more often than they are sensors. Check the pass-through connector at the gearbox for oil contamination and corroded pins, and follow the loom around the bellhousing looking for chafing against the casing or a heat shield. This is the cheap end and it is where the answer usually is.
- The sensor breaking down when hot. A sensor that works cold and drops out at operating temperature is a classic intermittent. Many VAG transmission modules store gearbox oil temperature in the freeze-frame data alongside the fault - if it is high every single time the code sets, that points strongly this way.
- Fluid level or condition. Low or aerated fluid, and metal debris from clutch wear collecting on the sensor tip, both produce dropouts. Have the level checked properly at the specified fluid temperature, and look at what comes off the magnet when the filter is changed - heavy metallic paste there changes the whole conversation.
- Internal mechatronic or valve body fault. On many VAG boxes these speed sensors are built into the mechatronic unit, so a genuinely failed sensor means that assembly. Because it is the expensive answer it should be the last one reached, only after the external wiring and the fluid are proven good - and when you do get there, ask about a repaired or reconditioned mechatronic as well as a new one, since a known sensor fault is exactly what the rebuilders deal with.
Worth knowing: Get the freeze-frame data recorded before anyone clears the code. Whether this only appears once the gearbox is hot, only in one particular gear, or only over rough surfaces is what separates a sensor from a wiring fault from something internal - and the moment the code is cleared, that clue is gone until it happens again.
Reading the code is the easy part
A code names the circuit that complained. What tells you why is watching the sensor behind it while the engine runs — and that is where a code reader stops and a diagnostic tool starts.
VAGPULSE reads every module in a VW, Audi, Skoda or SEAT — not just the engine — shows the live measuring blocks behind this fault, gives you the freeze-frame conditions it was logged under, and clears it once you have fixed it. It also does what a generic OBD reader cannot on a VAG: service resets, coding, adaptations, and Stage 1–3 flashing with your original file saved first.
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Common questions
What does P0794 mean?
P0794 means Intermediate Shaft Speed Sensor A Circuit Intermittent. The fault comes and goes, which points at a connection that only breaks under vibration, heat or load.
Can I drive with P0794?
The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.