X100 Engne Failsafe Message when engine compartment is hot

My first post to this site. I get a ‘Engine Failsafe Mode’ message when the engine compartment gets quite hot, notably in really hot weather (30+ degrees Celsius), even though engine temperature (coolant) is normal). I get an SPC +1, SPC -1 code when I check. I suspect a bad solder joint in the ECU . Local Jag mechanic suspects instrument pack issue. Any insights? Thanks