P1667 TCV Circuit malfunction

Toyota's TCV stand for Tumble Control Valve. Problem can be in VSV (vacuum switching valve) controlling vacuum actuator to close-open six small throttle plates inside intake manifold.

Hi,
I am facing a similar problem in a 2003 Toyota crown. Did you resolve the issue?

This post is pretty old I don't know if they will come back can I ask which engine you have?

We faced P1667 error code on 1JZ-FSE and 2JZ-FSE engines. Check and replace mentioned above valve if failed.

The engine is 2JZ-FSE. I have tested the valve and it doesn't seem to be working. Will replace with a new one and let you know guys

Please let us know what you find. We are interested to see what it is.

The problem was in the vacuum switching valve, not the electrical connection. Once I replaced the valve with a new one, the check engine light disappeared. Funny thing is, the dash board was previously displaying TRC and VSC errors before but after replacing the above valve, all these errors disappeared; don't know how they were all connected.
Anyway, thanks to everyone who chimed in on various ways to troubleshoot the issue. Problem is now solved.

Good to hear, please use 2CarPros anytime we are here to help.

I seem to have solved one problem while causing a different one. After replacing the vacuum valve (and getting rid of the check engine light), the car now is having a hard time starting. After turning the key, the engine will keep cranking without fully starting for about five times before it fires. What could be the issue?

It sounds like you may have a vacuum leak lets run down this guide to see what you find:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

This might help as well:

https://www.2carpros.com/articles/engine-cranks-excessively-before-starting

Please run down this guide and report back.

Thanks for the tips, I'll let you know what I find.