2000 Mazda Millenia Madness!


I have the following problems with my 2000 Mazda Millenia - #'s 1 & 2 just started yesterday 1)Having to break 50 feet in advance in order to come full stop. 2) while at idle or in park, engine is revving wildly! 3) lock on driver’s side door will not lock when pressing the lock button, must do so manually for individual door, in order to lock (also accompanied by a loud screech) .

Any advice (concerning the aforementioned) would be appreciated!!


  1. have the codes downloaded. I’d suspect the IAC circuit is causing the engine to try to overcome the brakes.

  2. have the codes downloaded. I’d suspect the IAC circuit.

  3. I’d suspect either a deceased lock solenoid or perhaps even a short to ground in the wiring harness where the wires feed through the holes from the chassis to the door. The wires get constantly bent and unbent there and the insulation has been known to fail over time.

I’m sorry to have to point this out, but if you ignore problem #1 for more than a few hours, you are not being a responsible driver.

What will you do when a small child suddenly darts out in front of your car?
You cannot anticipate an event like that, so “BRAKING 50 feet in advance” will not prevent you from running over that child. Or, on a somewhat less dramatic note, when someone pulls out in front of you suddenly from a side road, you will also be unable to brake 50 feet in advance. In either case, you will have an accident that might be avoidable if you act responsibly and take the car right away to a qualified mechanic (NOT a chain operation like Midas, Meineke, Monro, Sears, Pep Boys, etc.) for an examination of the braking system.

While the car is in the shop for the emergent brake problem, have the mechanic check for reasons why the engine is racing, as this could be related to the braking problem. Possible reasons include a bad Idle Air Control (IAC), but rather then telling him to replace that part, allow him to diagnose the cause himself. If you want to have the mechanic pursue the lock problem while the car is in the shop, that might be a good idea also, but this is certainly secondary to not being able to stop the car properly.

It Sounds Like The Brake Booster Is Defective And Is Leaking Vacuum And / Or There’s A Vacuum Leak In A Hose Or Connection.
The vacuum leak can cause the braking and revving problems.

I don’t think the door lock problem relates to this at all.

As VDC Driver advises, get this braking and revving problem fixed ASAP.

Thanks for the advice,

The onset of the braking issue occurred last night at 8pm (when most mechanic garages are closed) I have not driven it since- unsure if I should risk driving to the shop, 5 miles away, or have my baby towed.

Furthermore, as a female, I must, at the very least, have a general idea of what the impending diagnosis may be, before taking the car in, or will certainly increase the probability of receiving a huge bill with possible bogus recommendations.- Which has transpired more than a handful of times! In this regard, I think I am both a responsible driver and consumer.

I do appreciate your post, as well as others (Keep 'em coming)!

Many thanks from the Millenia and me :slight_smile: I will keep you posted about the results!

Thanks For The Update. Keep Us Posted.

I would agree with “comon sense” here. Question though: is this the Miller cycle engine? (diffrent animal all together)

Yes, if this car is the “S” model Millenia, that means that it has the Miller Cycle engine. Most mechanics have never worked on this type of engine, and since it has its own peculiarities, this may necessitate a visit to the Mazda dealership.

Those “S” Models Have The Little Miller Cycle V-6s With Superchargers And Expensive Replacement Parts.

It could just be the normally aspirated powerplant.