I have a 2006 FEH and it's not dropping into EV mode as often as it used to. After the initial warm-up, it will, but as you drive it it stops going into EV mode. Mileage is pretty lousy - especially in stop and go traffic. I can hear the fans on in the back. I don't get any error codes from my bluetooth OBD unit. While driving, I can occasionally hear a clunk from the front end. It's almost as if the electric unit wants to assist but can't. I don't know. Maybe it's the blend door but it sounds like it is coming from the front.

Any ideas? I have 203,000 miles on it.

 

NiMH batteries lose capacity over time, heat and use. Eventually, it will reduce the usable capacity of the battery to where the efficiency is impacted. not sure about the clunk, but the rest of it sounds like typical battery deterioration.

 

Well, it worked fine a couple of weeks ago - until my A/C got low on coolant. I recharged it but the EV is not working like it should.

If the batteries were low, wouldn't the system check tell me so?

 

No. Unless certain trouble code criteria are met. A battery can have as little as 30-40% of its rated capacity and perform normally in most situations.

If your rear A/C isn't cooling the battery as effectively, the increased battery temperature causes the car to decrease battery utilization.

 

How do you know if the blend door is working (or not)?

 

It generally codes if it doesn't.

Have you tried Forscan on the following:
PC with a MiniVCI cable
PC and bluetooth adapter
Android and bluetooth adapter

Most "run of the mill" OBDII options including Torque are inadequate for the FEH.

 

Forscan is giving me P0A81-60 and P2521-FF/P2524-FF.

I assume the last two are because the air conditioner was on when I ran the test.

P0A81 seems to indicate the fans for the battery pack are not working, even though I can hear them.