Volvo All Engines (2010 Emissions) Fault Code: SPN 177 FMI 0 PID: Transmission Oil Temperature

The J1587 and J1939 serial data lines are used as the standard communication link for on-board vehicle instrumentation, off-board service diagnostics and fleet management.
The transmission oil temperature sensor sends a signal to the instrument cluster module which relays a signal to the engine control module (ECM) via the data link. The signal is used to demand fan activation. If the transmission oil temperature gets too high, a yellow check lamp or red stop lamp will illuminate. The engine will also derate.

Observable symptoms
1) Engine de-rated

Probable cause
1) Low oil level, Transmission
2) Oil temperature sensor
3) Oil cooler
4) Transmission overloaded