Regen braking on car being worked on

[BlueRidgeSquatch]

So I'm not going to get into the weeds with the issue I have with my FFH, but apparently no one has dealt with it before. The electric motor was trying to start the ICE, but it cranked and wouldn't start. Obviously this has significantly drained the HVB. This idea might sound stupid, but can I tow the car around my neighborhood with the brakes being slightly pushed to engage regen braking and charge the HVB?

I don't see why it wouldn't work, but of course I do have my concerns. I just need to keep charge in the HVB so that I can attempt to start it from time to time while trying to figure out the problem. I've already taken it to the dealer and after 5 weeks, they can't figure out what's wrong (heard them in the background saying they don't have a clue) and suggest a new engine. I really don't think they know a thing about hybrids because for weeks they were waiting to hear back from Ford on what they thought was wrong. So much for mechanics that troubleshoot and diagnose ?

[murphy]

Is the dealer that you took it to electric certified?  If they are not certified they don't know anything about the car.

 

Have you checked the spark plugs and the fuel injectors and the fuel pump.

 

The car is not supposed to allow you to drain the battery.  At some point it should stop trying to turn the motor.

[BlueRidgeSquatch]

I'm honestly not sure. I wasn't even aware of that certification. This is actually the first time I've ever let someone else work on one of my vehicles and just assumed the dealership would be qualified.

 

Not yet. I'm about to go pick up my car this afternoon. I was going to go through and check those things, as well as all fuses and relays. I'll scan it with Forscan and see what I can see as well.

 

The car stopping me from turning the motor over is what I'm trying to avoid. If it gets to that point before I can diagnose/repair it, I'll need to bring that battery level back up so that I can try to start it later. That's why I was trying to figure out how to charge it back since there doesn't seem to be a way for an individual to do that.

[murphy]

Go here:

 

https://owner.ford.com/service/dealer-locator.html

 

and check the certified box before doing the search.

[BlueRidgeSquatch]

Thanks! Looks like the closest one is 80 miles away ?

I'm still going to take it home and try to do what I can on it before towing it that far away. I have a feeling that in one weekend I'll do more troubleshooting than Obaugh even attempted in 5 weeks.

[MeeLee]

sounds like a problem I've been experiencing occasionally.
When I run my CVT to the max gear ratio (running 1.1-1.2k RPM @75MPH), it tends to not start the engine as well (allowing it to run well below 1k RPM, usually 500-750rpm).
I can still cruise at 30MPH, but the engine wouldn't run properly.
It seemed to help by just pressing the throttle down quite a bit, allowing the engine to rev higher. Once it hits past 2k RPM the issue seems to be resolved.
On a different note,

I've also experienced belt slip, when accelerating on an on ramp to the highway.
I hear the engine revving higher, but the engine tach doesn't reflect that.
Which makes me believe it doesn't actually read engine RPM at the engine, but rather somewhere along the transmission.

On other occasions, the car was in N, and the engine came on, to charge the battery (because I was running AC), and I did not see engine RPM go up in the display, which confirms the idea that engine RPM isn't read out on the engine.

 

Perhaps other forum members can confirm that by leaving the engine in Neutral, enabling L-mode, and pressing the throttle all the way down, the engine will start and idle for charging purposes.

It should start from the 12V battery in the trunk.

Measure the 12V battery voltage, and have someone check the engine starter, as the engine should have a 12V starter aside from the electric high voltage motor to start it with.

[murphy]

It does not start from the 12 volt battery in the trunk.  The car doesn't have a traditional starter motor or an alternator.

The engine is started by one of the electric motors driven by the high voltage battery.

There are no belts in an eCVT transmission.  The engine only drives the wheels at very high speeds.  At all other times the wheels are driven by an electric motor.

Most of the time there is no relation between engine RPM and wheel speed.  The accelerator pedal is not connected to the engine    It is connected to the computer.

The computer decides what RPM to run the engine.  My car is 8 years old and I have never had the  RPM on the display since it is useless information.

 

[mwr]

7 hours ago, murphy said:

The engine only drives the wheels at very high speeds.  At all other times the wheels are driven by an electric motor.

That doesn't sound right to me. Often at normal in-town speeds I see (and hear) the ICE running and the also the HVB charging, which means the ICE is both driving the wheels and using the electric motor as a generator (not driving the wheels).

[murphy]

53 minutes ago, mwr said:

That doesn't sound right to me. Often at normal in-town speeds I see (and hear) the ICE running and the also the HVB charging, which means the ICE is both driving the wheels and using the electric motor as a generator (not driving the wheels).

The engine runs to provide electricity so an electric motor can drive the wheels.  It is physically impossible for the engine to drive the wheels in reverse.  There are no gears to shift in the transmission.

The engine does NOT direct drive the wheels at low speed.  It's an electric car.  Have you not noticed that you can accelerate the car and the engine RPM does not change?  The computer controls the engine to achieve maximum efficiency.  There are two electric motors.  See if you can find the description of the Toyota eCVT video on YouTube.  Ford is the same.

[Waldo]

 

I agree with you though on the tach, I started to use it when I first got the car, but quickly realized it was totally useless and haven't used it since.  For the record, the RPM data comes from the crankshaft position sensor.  How could the PCM run the engine timing and fuel injectors if it didn't know the exact engine speed?

Edited March 29, 2021 by Waldo

[mwr]

1 hour ago, murphy said:

The engine runs to provide electricity so an electric motor can drive the wheels.  It is physically impossible for the engine to drive the wheels in reverse.  There are no gears to shift in the transmission.

The engine does NOT direct drive the wheels at low speed.  It's an electric car.  Have you not noticed that you can accelerate the car and the engine RPM does not change?  The computer controls the engine to achieve maximum efficiency.  There are two electric motors.  See if you can find the description of the Toyota eCVT video on YouTube.  Ford is the same.

>The engine runs to provide electricity so an electric motor can drive the wheels< That's one thing the engine does but not the only thing. It often directly drives the wheels.

>Have you not noticed that you can accelerate the car and the engine RPM does not change?< Sure, the computer controls the engine speed and the eCVT provides the correct "gear ratio" that matches that RPM to the car's speed.

[Waldo]

I think the key is the system isn't related to "speed", its related to load.  If you punch the throttle, it will directly engage the ICE to the wheels at 1mph and up.  But if you're driving at light loads it can run the ICE to charge the battery while maintaining enough electric power to keep the vehicle moving.

[MeeLee]

On 3/29/2021 at 2:56 PM, murphy said:

 

Quite a few times, I see the engine run at 250-750rpm on a cold start, at <35mph.

It basically idles, and pushes the car at idle rpm.

Once warmed up (a few seconds in), it'll usually run at 1-1.5k rpm minimum, regardless of car cruising speed.

I've had my hybrid accelerate from a dead stop from the engine alone.

And tach does work mostly, but has some bugs in it.

It's actually the only indicator on the left, that shows some sort of valuable info.

All other info on the left panel is useless to me (save for mpg data, which I can see that exact same data on the right panel).

 

With the phev, you can charge the battery enough (like 30 min) to start the engine by fully pressing the throttle in park mode.

Or, while driving, put the car into D (drive) mode, and then enable L-mode, which will allow the engine to run at higher rpm, and allows it to start easier.

 

For the hybrid, you may be in a pinch.

I always believed ford engineers must have foreseen what would happen if the high voltage battery was drained, and at least either equipped the hybrid with a starter motor, or allow the high voltage motor to start on the 12V battery. Either way, measure the 12v battery. If it's empty, try using jumper cables on it, and see if that helps.

 

Some people say you can't jump start from a cvt, others say you can damage the cvt when towing with the front wheels on the ground,

Yet others say the torque converter won't allow your engine to rotate at all, despite of pushing/pulling the vehicle...

I'm no expert at this...

Edited April 4, 2021 by MeeLee