The Opus format began on 710 AM (XEMP) in 1983. That same year, 94.5 FM, the last full-power FM frequency available in Mexico City, was put up to attract noncommercial permits. Several groups — the IPN and IMER among them — jockeyed for the station, with IMER winning. Opus moved to the new 94.5 XHIMER-FM on July 4, 1986, when 50 kW transmissions commenced.[3] The station received authorization for a power boost to 100 kW in 1991, but IMER was not able to install a transmitter capable of outputting 100 kW until 1999.
The concession for XHIMER-FM lapsed effective April 13, 2023, due to failure to file a timely renewal. The Federal Telecommunications Institute granted a new concession, which initially bore the template call sign XHCPDO-FM, which was changed back to XHIMER-FM along with those for five other stations whose concessions were lapsed and reawarded.[4]
The station used to broadcast in HD Radio;[5] this transmission was formally launched on September 17, 2012. Its HD2 signal was co-owned XEB-AM and its HD3 was Jazz Digital, all of which became silent in early-2020 due to operating costs.[6][7]