There are two relays in the Instrument Panel Electrical Center (#38 and #40). The daytime running lamp relays are located in the instrument panel fuse box under the passenger side toe-board (not in the engine compartment fuse box).These relays are energized (and turn on the DRLs) when the Ignition is on and the parking, headlights and turn signals are off. (The diagram on the cover of the electrical center shows the relay locations).

To prevent the DRLs operation, remove the relays from the panel and carefully remove the covers on the relays. Slip a strip of business card or thin plastic between the common and normally open points. (For those who are not technical, look at side of the relay - there are three silver colored points. Put the strip between the points that are separated) put covers back on relays and reinstall in panel.

This modification will also prevent the turn signal lamps from turning on when locking from the FOB and unlocking at night. ("approach" lights) Removing relays generates 2 BCM DTC's, but no more are generated once relays are replaced.  (BCM checks for relays present) these DTC's will clear with 50 ignition cycles or you can reset them manually. (display and reset procedures click here).