One problem related to wiring has been reported for the 2007 Toyota Yaris. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2007 Toyota Yaris based on all problems reported for the 2007 Yaris.
In approximately may 2015 I replaced the hub on the right rear wheel. After the item was replaced and abs sensor reattached I have had the issue of abs and emergency brake light on continually on the dash upon startup, they never go off!!! needless to say I have lost abs since that time. I have had the diagnostics checked and there were three abs relay sensor warning faults, front right, and both back wheels. Since then I have replaced all the wiring harnesses for the three wheels. The diagnostic shows no abs relay faults. The abs and emergency brake light still incessantly stay lit on the dash. I have also tried to reset the internal computer by removing the negative terminal on the battery. I am in the military and have read many issues and faults regarding this abs issue, and it would be very expensive for Toyota or a mechanic to try and fix this issue, that I have seen occurring on many Toyotas across the USA. That's why I have tried to resolve the issue on my own. Now I am pcs'ing to my next duty station, yet if I don't get the dashboard lights to turn off I may not be able to ship the car.