Conner's funeral will be held at the Hamilton Park Crematorium Chapel at 11am.
In lieu of flowers, the family has asked for donations to be left in a wishing well.
Conner has been remembered as an inquisitive little boy who had "the most gorgeous blue eyes".
On Thursday, the boy's grandfather said Conner's mother had been busy making school lunches when the boy snuck out the ranch slider.
The grandfather, who did not want to be named, told the Herald the boy then walked up a short section of gravel driveway and into the path of a car.
He said the boy's father was not in the house at the time, but was working in the milking shed.
The couple had lived in Waitakaruru for a while and their other children attended the local school.
The grandfather said although the boy was only 18-months-old he would prefer to analyse his surroundings than play with his toys.
"He was an inquisitive little fulla and always wanted to know why, say, that tree was green. He wouldn't play with his toys, he would start pulling at (the tree), and he just obviously walked out the gate and got hit."
Family and friends of the little boy have rallied to help fundraise money to help Conner's parents.
A GiveALittle page has been set up in a bid to help give Conner's family closure, following his sudden tragic death. The funds will be used specifically to help the family move away from their current home - outside of which Conner died.
The tribute on the page reads:
"Conner Ian Lance Valvoi was a beautiful, happy baby boy with blue eyes that could warm your soul at one glance. He was loved and adored by his parents, Wendy Wallace & Dylan Valvoi, who only 1 week prior celebrated their engagement.
"On the 3rd March 2016 their lives changed forever in a split second when this gorgeous boy was involved in a tragic car accident that claimed his 18-month-old life. He has left behind his family, including three older siblings, Riley, Kayleigh and Savannah.
"This amazing family have endured more heart ache than any family should ever have to. Wendy and Dylan's daughter, Savannah, also suffers from tumors on her vocal cords and lungs which requires her to receive hospital treatment on a regular basis. Savannah was unfortunately receiving treatment in hospital when the accident happened. She has already had more than 260 operations to date.
"There can never be enough time to mourn such a tragedy, however, they should be given time to do so properly and away from the place of incident, currently their home. They currently cannot afford to stay away from work or to move away to another home. They have funeral expenses, moving expenses and living expenses which all need to be met.
"Dylan will be starting a new job on the 1st June and we would therefore like anyone and everyone to kindly donate even just the smallest amount to help them move, live and grieve properly for the loss of their son. Our goal is to reach enough money that would allow them to move, live and not work until the new job in June."
• To donate, visit: https://givealittle.co.nz/cause/connerlives#
