Today the check engine light came on. Turns out I need a new Leak Detection Pump - Mazda is ordering it, and it will be totally covered under warranty, so no biggy really.

I have two questions for the mechanics out there:

1.) What does it do? (yes detects leaks - but what kind etc?
2.) I have heard that there is an air intake near the back of the car, and water can get in there and kill the pump (according to a post at another forum). Apparently at highway speeds in the rain, mist can get in there and accumulate, ultimately destroying the pump. - Any truth to this? And if so, how can it (if at all) be avoided?

Also, I needed a new headlight - was surprised that this was free under warranty. Woo hoo.

 

The LDP using pressure and vacuum sensors to determine if there is a leak in the EVAP system. It closes the air intake and purge valve and compares the vacuum. The MIL turns on if there is a fault.

The intake at the rear of the vehicle has a fliter that can get dirty/clogged by water and road debris.

Hope this helps.

 

Would a bad leak detection pump be easy to detect through error codes?

Our Mazda5 had a check engine light come on, but I'm told by the mechanics that the code thrown could only point to a circuit that had 3+ major components on it (including MAF, Throttle body, and others).

Ultimately, the leak detection pump was replaced only after long efforts at diagnosis and a reported short in wires running back to the fuel tank.

Reasonable? or was the diagnosis/repair more complicated than it needed to be?

Thanks for any input.

 

I don't like to comment on other technicians diagnosis as I was not there and don't know all the important details.

There are certain codes that can lead a tech to the LDP. However codes are not the be all of diagnosis. They only lead the tech in a direction where he/she must use his experience to diagnose the fault.