Engineers trust TPMs who make their jobs easier. That sounds obvious. The ways it plays out in practice are specific enough to be worth naming.
The first is protecting engineering time. Every meeting that does not need an engineer in it, every status request that can be answered without pulling someone out of heads-down work, every decision that can be made without a technical opinion is a gift. TPMs who protect engineering time get trusted. TPMs who schedule engineers into everything get routed around.
The second is understanding the technical constraints well enough to advocate for them upstream. When leadership asks for a date that is not possible, the engineer should not have to explain why. The TPM should already know why and should have surfaced it before the ask became a commitment. That is a specific kind of competence engineers notice and remember.
The third is honesty about trade-offs. Engineers are used to being told what the deadline is and asked to make it work. The TPM who instead says here is the deadline, here is what fits in it, and here is what moves if I add more is treating the engineering lead as a partner in the decision. That is different, and most engineers feel the difference immediately.
Trust takes time and specific behaviors. It does not come from announcing that you are technical or from asking about the technology in meetings. It comes from consistently doing the things that make engineers' work easier and their judgment respected.