Having my first real FEH problem and need some advice. About two weeks and 300 miles ago I had a SSN incident on the freeway. Creeping along in stop and go traffic, started to accelerate but ICE wouldn't come on, got SSN message and alarm instead, and I limped off the freeway in EV. Cycled the ignition a couple of times and everything went back to normal.

But from that incident forward to now, the FEH seems to be lacking in regenerative braking, I have to brake more often and more forcefully than I'm used to. Very little regen below 30mph in L, and on long downhills the ICE revs to 4k rpm sooner rather than recharging SoC to 58% or higher.

All parameters on the Scangauge are normal and no codes. I've checked battery temp (80), MECS temp (87), water temp (185), HV battery filter, 12vdc battery. I can hear the HV battery fans running when the ICE is off and they don't sound any different. The A/C is not being commanded on. The dashboard "Charge" gauge moves in the correct directions for charging and discharging.

So any thoughts on how I could lose about 50% of my regen braking when all system parameters seem normal?

 

I don’t know if this could help solve your issues, but a friend had the same problems with his braking pedal too - having to really jam it and not get the responsiveness that it's supposed to give. Something to do with bubbles in the braking fluid pipe or something like that. It's gonna be tough to fix a problem like that since apparently you have to drain out everything and kinda suck the air out or something? Here's hoping you have an extended warranty or some good insurance for that!

 

Hi Rowan,

Thanks for the reply. In my case it's the regenerative braking from the hybrid system that seems to be the problem, not the mechanical brakes. But thanks for the interest!

 

Keep us posted on this one please... I'm wondering if there's something in the system that may be indicating to the computer that the battery is not being cooled. Obviously the temp is normal though. Other than that, I'm wondering if a battery "rebalance" might be in order. There are some outfits around that will do it for you but I'm not sure of the cost. It would be nice to know what the actual issue is before throwing money at it.

Is your AC blowing cold? This could be an indicator of poor battery cooling. I had to replace the AC pump at 195K on mine and it was definitely not cooling properly at that point. The only thing I noticed as far as drivability was that the ICE would not shut off as often as it should.