The transmission control module is not receiving a valid engine speed signal, so it cannot time shifts correctly.
P0725 — also written PO725, P 0725, 0725 — is the OBD-II code for engine speed input circuit malfunction. Same code, same fix: this page covers every spelling of it.
P0725 is a transmission fault code, typically costing £120–£700 to put right in a UK garage.
What causes P0725?
- Crank sensor fault
- CAN communication fault between engine and gearbox modules
- Wiring or connector damage
How P0725 is fixed
- Scan both modules for related codes
- Replace the crank sensor if it is dropping out
- Repair the CAN wiring
P0725 repair cost in the UK
Most P0725 repairs land between £120–£700 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Can you drive with P0725?
Expect limp mode. Recover if the car will not shift.
Urgency: high.
What P0725 is telling you
Gearbox faults are logged when the shift the control unit asked for is not the shift it measured. Fluid condition and level affect that measurement as much as any electrical part, which is why the fluid is checked before anything is dismantled.
On P0725 specifically — engine speed input circuit malfunction — the stored code records the moment that check failed, not the moment the part gave up. That gap is why two cars with the same code can need completely different repairs.
How P0725 is diagnosed properly
Each of the known causes is ruled in or out in cost order, cheapest and most likely first. On P0725 that means working through them like this:
- Crank sensor fault — compared against live data and a known-good reference before it is condemned — a sensor reading the wrong thing accurately is a different fault from a dead one.
- CAN communication fault between engine and gearbox modules — checked for outstanding manufacturer updates before any hardware is touched.
- Wiring or connector damage — checked with the loom flexed and the engine warm, because a wiring fault that is intermittent when cold shows itself under heat and vibration.
An hour of diagnostic time on P0725 routinely saves more than it costs, because the alternative is buying the most expensive part on that list and hoping.
The repairs that actually clear P0725
- Scan both modules for related codes
- Replace the crank sensor if it is dropping out
- Repair the CAN wiring
After the repair the code is cleared and the car is driven until the relevant readiness monitor completes, rather than handed back as soon as the light goes out. A code that has only been erased will come straight back on the next drive cycle.
What happens if P0725 is ignored
This is a stop-and-sort fault rather than a wait-for-the-service fault. Ignoring it risks turning a sensor-money repair into a component-money one.
For reference, P0725 typically lands at £120–£700 all-in at an independent garage in the UK — main-dealer quotes for the same job usually sit above that.
Getting P0725 looked at
Bob's Mechanical Repairs is an independent garage in Birnam, Dunkeld, Perthshire, with 32 years of Bob's experience on the tools. If P0725 is showing on your car, bring the scan results with you — we will read the live data ourselves, tell you which of the causes above it actually is, and price the repair before any work starts.