P0725Engine Speed Input Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- The transmission module needs engine speed for converter slip, shift quality and to check the turbine speed. Today it almost always arrives over CAN from the engine module with a validity flag; only GM's 2007 Allison 1000 tables show a separate engine speed sensor read by the transmission module. P0725 is the general fault of this input; with CAN it means the engine module marks its speed value as invalid. Saab's Aisin transmissions and a 2006 GM table set it after about 4 s, the GM table with immediate MIL. A Saab bulletin notes that behind P0725 there is always a crankshaft or camshaft sensor code in the engine module (P0016, P0335–P0339) – so read the engine module first. Limp mode follows; a completely missing CAN message is U0100.
- What you may notice
- Transmission warning lamp, possibly check engine light
- Torque converter clutch locked out
- Harsh shifts or limp mode
- Often an engine code (crankshaft sensor) as well
- Likely causes
- LikelyCrankshaft or camshaft sensor fault in the engine module (speed invalid there)
- PossibleCAN fault between engine and transmission module (wiring, termination, connector)
- RareEngine module software or fault
- RareTransmission module faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €50 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.