Hello! I've been a two-week lurker here cause I just got my very own FEH. A 2005 AWD with 110,000 miles.

Last week I got the MECS pump swapped out at my local dealer. I wasn't having any problems with my car at all, but figured I should take advantage of the recall while I still could.

HOWEVER, ever since I got the pump swapped out, now my car won't go into EV mode after about 30 minutes of driving! And the fans in the back sound SUPER loud... I can't help but think the dealer did something wrong and caused some issues. The only problem is, this is my daily driver and I need it for school/work so I don't have time to take it back to the dealer any time soon.

But I started doing some research on this forum before posting and figured I should let you know all the info that could be effecting this before jumping to conclusions.

- last week when it was pretty cold (for CA) the heater would blow lukewarm, then straight cold while I was driving around the city
- Didn't bother checking AC until this week when it's back in the high 80s/90s and the AC blows kind of lukewarm, kind of cold but not really
- ONE time since I got the car I got the service engine soon light on randomly while I was driving. But after I turned the key off and back on it went away.
- when I turn the key on halfway but don't start the car, the message screen keeps blinking "service emissions system soon" until I start the car
- when I turn the key on halfway but don't start the car, I do hear a little pump thing going by the radiator, i think that is the MECS pump that was just changed?
- the fans in the back by the battery are VERY loud when EV mode isn't engaging
- the fans in the front are also very loud when EV mode isn't engaging, by the radiator?

I think that is everything I noticed in the last few weeks. I really love this car but it is becoming a bit of a money pit. I ordered a scan gauge II from AutoZone (they are having a 20% off with free shipping to home promo right now, out the door was $138 and change) so I'm hoping to get some more data about the battery temperatures and stuff.

But I was wondering if anyone had the same issues, and if they knew what might be going on.

Thank you so much!

 

Can you clarify which of these symptoms occurred before you had the dealer replace the MECS pump and which only occurred after?

 

Yes, so sorry!

lukewarm heater = before and after pump change
lukewarm AC = after pump change, didn't check before so unsure :/
check engine light = before pump change, hasn't come back at all
key halfway pump sound, service emissions soon check = yesterday night after pump change
loud fans in front and back = after pump change

thank you!

 

If you have lukewarm A/C, the system may not be able to cool the hybrid battery pack sufficiently to keep it in the temperature range that the software requires for EV mode. That would also explain the loud rear fans as the system is working hard to try to drop the hybrid battery pack temperature.

Once you get your ScanGauge, you will be able to confirm this as you can directly monitor the hybrid battery temperature.

 

There is a actuator in the back that opens and closes a flap associated with the rear fans and cooling the battery. Common issue pretty easy diy fix, cheap.

Here's one of many threads on this:

https://www.greenhybrid.com/forums/f...t-today-28229/

 

Lukewarm heater could be aux. pump in the ICE coolant system.
My 2005 FEH aux. pump not working and get cold when ICE is off at a long
stoplight. Not MECS pump a second pump.

 

is AC used to cool the hybrid battery?

 

On 2005-2009, yes.