Scottish Fire and Rescue had initially said they had responded to a fire on a train near Crossmyloof station.
However, a ScotRail spokesman clarified there had been no fire.
He said: "There was no fire, this was an automated safety system which was triggered sending steam into the carriage. At no time was anyone in danger."
Commuters faced rush-hour chaos yesterday morning after the incident on the South Side of the city.
As reported in later editions of the Evening Times, passengers were forced to evacuate the carriages of the 7.42am East Kilbride to Glasgow Central train.
More than 20 firefighters were called to Crossmyloof station after the alarm was raised.
All rail services on the line, including trains from Giffnock, Thornliebank, and Pollokshaws West were stopped following the incident.
The train driver raised the alarm at around 8.15am yesterday.
Fire incident commander, station manager Stephen Carson, said: "We received a call from Network Rail reporting a fire in the engine compartment of a train.
"The train's firefighting system had alerted the driver and activated its automated foam extinguishing equipment.
"Firefighters ensured the affected engine was isolated and that passengers were safely evacuated from the train to the nearby station.
"First Scotrail engineers checked the train.
"It was removed to workshops where their specialist engineers were able to strip down the affected part of the train to establish the cause of the incident.
"We understand their investigation found a faulty sensor had activated the fire suppression system and raised the alarm."