Infrastructure Minister Nichola Mallon has said she cannot give a date for when MoT testing centres will return to business as usual.
MoT tests for cars and light vehicles were suspended last month following concerns over lift equipment.
Cracks in vehicle lifts were first detected in November but the problem rapidly escalated in January.
Giving evidence to the infrastructure committee at Stormont on Wednesday, Ms Mallon said work is under way but she is not willing to speculate on dates for full resumption yet.
"At this moment in time I can't give the committee a date," she said.
"I have appointed as one of the two independent reviews an engineering expert company. They are currently on site assessing.
"They have been tasked with providing to me independent expert advice on business recovery.
"That will include contingency arrangements in the here and now to maximise capacity but also the steps required to get our MoT centres back fully operable as quickly as possible.
"But I am not and I would not speculate or in any way lead the committee to a position where I can't stand over it, so at this moment in time I cannot give a date as to when we will have the MoT centres fully and safely operable."
She was asked by committee chair Michelle McIlveen if a decision has been taken to purchase new lift equipment.
Ms Mallon said: "I have instructed for independent assessments of all of the lifts so that we can ascertain which can be repaired, but I have asked officials to prepare a sub for me on the purchase of equipment, including a range of options – it's around repair, it's around hiring if it is a possibility and also the purchase of equipment.
"The wheels are in motion in terms of putting all of the options out there and assessing the best way of going forward."
She added: "I want to assure the committee that my focus here is not just on firefighting and getting over this crisis, it's about having to take a look at the entire system and service."
Testing of heavy goods vehicles, buses and motorcycles remains unaffected by the current disruption.
Owners of cars and light vehicles which are five years old, or more, will be eligible for a temporary exemption certificate.
Younger cars and taxis are being prioritised for tests which will be carried out in the heavy vehicle lanes in MoT test centres.
Ms Mallon previously announced that she has ordered two independent reviews into how the situation came about, describing it as "not acceptable".
