Williams determined that a sudden loss of hydraulic pressure had led to Logan Sargeant's crash on lap 14 of the Dutch Grand Prix, however the team has yet to uncover the reason for the failure.
The hydraulic issue occurred as Sargeant hit the inside kerb at Turn 8, which shut down the car's power steering and propelled the American into the barrier.
Sargeant immediately reported that something had gone wrong just as he negotiated the corner, and an analysis of the FW45's telemetry revealed the cause of the crash.
"To explain what happened with Logan, he took a kerb that he had been hitting quite a few times on Friday and in fact, during the race," Vowles told F1TV.
"We had the engineer very quickly look through and he hit it in at least the last four laps [before the crash].
"On that particular lap, he lost hydraulic pressure. When you lose hydraulic pressure, your steering systems are hydraulic, so he had no steering assist and went off.
"This wasn’t a replication of what we saw before. What we need to understand is why we saw such spikes and why we lost hydraulic pressure there.
"He was gutted because you always question yourself, you question everything. He knows given how messy [the race] was, it was chaos out there, there were opportunities."
It was Sargeant's second crash of the weekend. The 22-year-old had done a remarkable job in qualifying to haul himself into Q3 for the first time this season, only to drop his car on the approach to Turn 2.
Williams nevertheless left the Netherlands with P8 and four championship points, courtesy of a strong drive in the mixed conditions by Alex Albon.
Vowles was once again praiseful of the Anglo-Thai racer's efforts and his increasing contribution to the team's progress.
"He is very good at providing direction to the team," Vowles said. "He is very good at understanding where the limitations and weaknesses of himself and the car are, and where he needs to focus.
"I think he has a platform now where we can talk about it.
"What we need is to provide him with a car that is continuously moving forward and developing over the next months and years."
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