P0725: Engine Speed Input Circuit
What to do
Expect poor shift quality and possibly a fixed gear. Ask whether any network or communication codes are stored alongside this one; on most vehicles engine speed reaches the transmission over the data bus, so a communication problem is a more likely explanation than a failed sensor.
What this code means
The transmission module is not receiving a usable engine speed value. It needs one for two purposes: to schedule shifts against engine load, and to compare against turbine speed, since the difference between the two is the slip across the torque converter.
The important structural point is that on most vehicles the transmission module has no engine speed sensor of its own. Engine speed arrives as a message on the data bus from the engine module, which owns the crankshaft sensor. So P0725 is frequently a communication fault rather than a sensor fault, and the productive first step is to look for network codes — a U-code naming lost communication with the engine module explains this one completely, while replacing a crankshaft sensor on the strength of P0725 alone rarely does.
Likely causes
Start here
- Loss of communication with the engine control module · specialist
- Faulty crankshaft position sensor · moderate
Less common
- Damaged data bus wiring · specialist
- Poor module ground connection · moderate
Rare
- Faulty transmission control module · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about P0725.