FFH factoids & parts quiz

[Texasota]

Continuing with the Hybrid Electric Control Software, the Creep Mode was the first item:

 

Driving Modes

There are five fundamental operating modes in the hybrid electric system:

• series mode

• electric mode

• positive split mode

• negative split mode

• engine cranking mode

 

Series Mode

The system operates in this mode when the engine is running and the vehicle is not moving. This is the preferred mode whenever the high voltage traction battery is charging, passenger compartment temperature control, high voltage traction battery temperature control or catalyst warm up is necessary.

Electric Mode

The system operates in this mode when the vehicle is propelled by the electrical power stored in the high voltage traction battery. The torque is supplied to the output shafts by the traction motor. This is the preferred mode whenever the desired torque is low and can be produced more efficiently by the electrical system than the engine. The electric mode is also used in reverse because the engine can deliver torque only in a forward direction.

 

Come on, GrySql! I'm not going to sleep a wink tonight until I get to read about the remaining three modes. You are a tease.

[GrySql]

This is like a Serial TV show, be patient and all will be revealed. Have some warm milk to calm yourself... :)

 

Did you catch that part where the ICE works only in Forward, the Traction Motor provides Reverse.

Edited December 20, 2014 by GrySql

[Texasota]

Did you catch that part where the ICE works only in Forward, the Traction Motor provides Reverse.

 

Yes, I did. It makes you realize how much the HVB and EV system is fully integrated into the design of this car. If the HVB somehow becomes fully discharged (or fails) you are going to be calling AAA.

 

Going to get some warm milk now and a couple of Meagan's cookies.

[SteveB_TX]

If the HVB ever fails, you will be calling AAA anyway Texasota (or in my case, Lincoln Lifetime Roadside Assistance!) :) On the flip side, if the HVB is fully discharged (which we all know is a BAD thing), the ICE will start up and and provide the required go juice to back up, unless the converter is toast, then yes, you will have to call AAA. You will still need to take your car in to the dealer, since your HVB should NEVER be fully discharged. Unless you are like GrySql and keep running tests to check his factoids! ;)

Edited December 20, 2014 by SteveB_TX

[lolder]

The system prevents the HVB from ever being completely disharged ( unless there is a system failure ). Only the HVB cranks the ICE so if the HVB is discharged, it's tow to the dealer time. Of course there was another problem also.

[GrySql]

Unless you are like GrySql and keep running tests to check his factoids! ;)

Factiod checking the gizmos and thingys is all done Ad Hoc using seat time and Heuristic methods. :headspin:

[GrySql]

NOTE: The following is general information only and and may not be complete. This information is for discussion only and not to be used for problem solving with your specific car. This information is not intended to replace or supersede any warranty, parts and service policy, Work Shop Manual (WSM) procedures or technical training or wiring diagram information. Seek qualified automotive help if your car is having drive-ability problems.

==

Continuing with the Hybrid Electric Control Software, the Creep Mode was the first item, below are items 3, 4 & 5 of the Drive Mode:

(There are five fundamental operating modes in the hybrid electric system:
• series mode
• electric mode
• positive split mode
• negative split mode
• engine cranking mode)

--

Positive Split Mode
The system operates in this mode when the engine is running and powering the generator motor which produces the electricity. The power from the engine is split between the path through the generator motor and the path to the output shafts of the vehicle. The electricity produced by the generator motor charges the high voltage traction battery or powers the traction motor. In this mode the traction motor can operate as a motor or as a generator to make up the difference between engine torque and desired torque at the wheels. This mode is preferred whenever the traction battery needs to be charged or at moderate loads at low speeds.

Negative Split Mode
The system operates in this mode when the engine is running but the generator motor is reducing the engine speed. This mode is never preferred but occurs if the engine is running, the vehicle speed is high, the high voltage traction battery is charged.

Engine Cranking Mode
The generator motor provides the engine cranking function to start or restart the internal combustion engine. When the PCM requests the engine cranking mode, the generator motor rapidly accelerates the engine speed up to about 950 RPM in about 0.3 seconds. When the engine speed reaches a calibrated speed the PCM commands the delivery of fuel and spark at the appropriate time.

Edited October 18, 2015 by GrySql

[mwr]

Negative Split Mode

The system operates in this mode when the engine is running but the generator motor is reducing the engine speed. This mode is never preferred but occurs if the engine is running, the vehicle speed is high, the high voltage traction battery is charged.

 

It seems to me my FFH operates in this mode sometimes under moderate acceleration from a stop, even when the HVB doesn't have a high SOC. Car accelerates with more EV than engine (no more than 1500 rpm). I really like that mode for acceleration; it's almost silent, and wish the car would use it more.

[Texasota]

Electric Mode

The electric mode is also used in reverse because the engine can deliver torque only in a forward direction.

While I was laying awake all night (thanks, GrySql) I was wondering more about this. Okay, the ICE can only apply torque in a forward direction. But, can the ICE charge the HVB while I am driving in reverse?

 

I was wondering if I would be in trouble if I drove down a dead end ally that was three miles long forcing me to back out all the way? I suppose I could stop and put it into park to allow the HVB to charge if charging in reverse is not possible.

 

Engine Cranking Mode

When the PCM requests the engine cranking mode, the generator motor rapidly accelerates the engine speed up to about 950 RPM in about 0.3 seconds. When the engine speed reaches a calibrated speed the PCM commands the delivery of fuel and spark at the appropriate time.

I'm guessing this largely explains why we enjoy the almost seamless transition from EV back to ICE running and powering the car. From most of the literature I have read, the FFH is amongst the best in making this a smooth transition.

[lolder]

Yes the ICE generates electricity in reverse. About once a year the Gen II 2010-12 FFH's periodically ( Re )-Condition the HVB by fully charging it for 15+ minutes and inhibiting EV completely. If you want to reverse before that is complete, the re-conditioning is cancelled so you can use EV in reverse. It may initiate again shortly and complete.

 

When you accelerate moderately forward, the ICE and EV contribute. Find a big empty space and floor it in reverse. The ICE will run but it is not propelling the car and you will see how strong the EV alone is.

 

The cars will not move without the EV system functioning. If that shuts down for a malfunction, the cars coast to a stop. The ICE cannot propel the car without the EV system functioning. The car will go a short distance of about a mile in EV if the ICE quits.

Edited December 21, 2014 by lolder

[jeff_h]

Yes the ICE generates electricity in reverse.

 

The ICE has charged my HVB in reverse probably 15-20 times, as my house is at the top of a hill in my neighborhood and if I time it just right the EV+ uses the HVB so it is very low and then when I go to back into the driveway and garage (another uphill) if right around that time it has passed the threshold where the HVB out of EV+ then the ICE will start and charge the HVB while I am backing uphill into the garage. I originally thought the EV was powering in reverse but have since read on various posts that it does not, so if that's the case then the ICE is definitely charging the HVB as I'm going in reverse.

[hybridbear]

I've wondered about that, but have no idea how to find out.

Since braking uses the traction motor for regen there is no creep fighting against braking.

 

Continuing with the Hybrid Electric Control Software, the Creep Mode was the first item, below are items 3, 4 & 5 of the Drive Mode:

(There are five fundamental operating modes in the hybrid electric system:

• series mode

• electric mode

• positive split mode

• negative split mode

• engine cranking mode)

--

Positive Split Mode

The system operates in this mode when the engine is running and powering the generator motor which produces the electricity. The power from the engine is split between the path through the generator motor and the path to the output shafts of the vehicle. The electricity produced by the generator motor charges the high voltage traction battery or powers the traction motor. In this mode the traction motor can operate as a motor or as a generator to make up the difference between engine torque and desired torque at the wheels. This mode is preferred whenever the traction battery needs to be charged or at moderate loads at low speeds.

Negative Split Mode

The system operates in this mode when the engine is running but the generator motor is reducing the engine speed. This mode is never preferred but occurs if the engine is running, the vehicle speed is high, the high voltage traction battery is charged.

Engine Cranking Mode

The generator motor provides the engine cranking function to start or restart the internal combustion engine. When the PCM requests the engine cranking mode, the generator motor rapidly accelerates the engine speed up to about 950 RPM in about 0.3 seconds. When the engine speed reaches a calibrated speed the PCM commands the delivery of fuel and spark at the appropriate time.

The one missing from this description is parallel mode. Larry has frequently pointed out that all these modes have inefficiencies due to conversion losses since both positive split & negative split involve conversions of mechanical energy to electrical energy then back to mechanical energy. The ideal mode for freeway driving would be to just have the ICE drive the wheels without electrical input. This is what the Accord Hybrid does via a clutch to get better highway MPGs than the Fusion. Toyota hybrids also typically do not consume or generate any mechanical power from the electric motors on the highway, sending the power directly from the ICE to the wheels. They also get better highway MPG than the Fusion. The Fusion will occasionally under ideal conditions only send power from the ICE to the wheels without involving the electric motors. However, since the FFH eCVT is not all mounted on one axle, like the Toyota eCVTs, it cannot really do this mode because power has to go through the traction motor which is mounted on a different axle and goes to the wheels.

 

While I was laying awake all night (thanks, GrySql) I was wondering more about this. Okay, the ICE can only apply torque in a forward direction. But, can the ICE charge the HVB while I am driving in reverse?

 

I was wondering if I would be in trouble if I drove down a dead end ally that was three miles long forcing me to back out all the way? I suppose I could stop and put it into park to allow the HVB to charge if charging in reverse is not possible.

 

I'm guessing this largely explains why we enjoy the almost seamless transition from EV back to ICE running and powering the car. From most of the literature I have read, the FFH is amongst the best in making this a smooth transition.

 

The ICE has charged my HVB in reverse probably 15-20 times, as my house is at the top of a hill in my neighborhood and if I time it just right the EV+ uses the HVB so it is very low and then when I go to back into the driveway and garage (another uphill) if right around that time it has passed the threshold where the HVB out of EV+ then the ICE will start and charge the HVB while I am backing uphill into the garage. I originally thought the EV was powering in reverse but have since read on various posts that it does not, so if that's the case then the ICE is definitely charging the HVB as I'm going in reverse.

Toyota hybrids cannot charge the HVB while in reverse, but this is because their ICE, traction motor & generator motor are all mounted on the same axle. Since the Ford design is different it is possible for charging while in reverse. This would mean that the ICE is spinning the generator motor to convert mechanical energy into electrical energy. Some of that electrical energy is then converter back to mechanical energy by the traction motor to propel the vehicle in reverse, while the excess electrical energy is stored in the HVB.

 

Since hybrids have an eCVT without changing gears there is no method to provide reverse torque from the ICE to the wheels.

[Texasota]

The Fusion will occasionally under ideal conditions only send power from the ICE to the wheels without involving the electric motors. However, since the FFH eCVT is not all mounted on one axle, like the Toyota eCVTs, it cannot really do this mode because power has to go through the traction motor which is mounted on a different axle and goes to the wheels.

HB, the above seems unclear. Sounds like you are saying that Parallel Mode does not apply to the FFH?

[hybridbear]

HB, the above seems unclear. Sounds like you are saying that Parallel Mode does not apply to the FFH?

It does & it doesn't. The Ford eCVT doesn't have a clear & direct path to the wheels like the Toyota eCVT & the Accord Hybrid clutch design. However, there are times where both the generator motor and the traction motor will show 0.0 kW or very close to 0.0. At these moments the gears are just transmitting the ICE power through the planetary gearset to the wheels without converting energy and experiencing conversion losses. I haven't done enough road trips since getting my Android tablet with Torque Pro last year to fully figure out the logic but I hope to do a long road trip in January and observe data over 1000s of miles of highway driving.

[lolder]

I am going to disagree. i believe the different architecture of the Toyotas and Fords does not cause these differences. The block diagrams are the same except for an additional planetary gear in the Gen III Prius to lower MG! speed to allow higher EV speed. Their modes are the same but implemented in slightly different ways and proportions due to design objectives.

 

The Toyota systems can charge in reverse. From Wikipedia Hybrid Synergy Drive entry http://en.wikipedia.org/wiki/Hybrid_Synergy_Drive:

 

"Reverse gear: There is no reverse gear as in a conventional gearbox: the computer feeds negative voltage to MG2, applying negative torque to the wheels. Early models did not supply enough torque for some situations: there have been reports of early Prius owners not being able to back the car up steep hills in San Francisco. The problem has been fixed in recent models. If the battery is low, the system can simultaneously run the engine and draw power from MG1, although this will reduce available reverse torque at the wheels."

 

It is rare that there is no electrical function at all as MG1 controls the transmission and engine speed but it is small at highway speeds unless the HVB charge is above or below the nominal target.

Edited December 23, 2014 by lolder

[GrySql]

Continuing with the Hybrid Electric Control Software:

 

NOTE: The following is general information only and and may not be complete. This information is for discussion only and not to be used for problem solving with your specific car. This information is not intended to replace or supersede any warranty, parts and service policy, Work Shop Manual (WSM) procedures or technical training or wiring diagram information. Seek qualified automotive help if your car is having drive-ability problems.

--

Normal Power Down Sequence

The TCM must conduct a normal power down sequence. Whenever the ignition is turned to the OFF or ACC position, modules powered up by the ISP-R circuit immediately shut down. However the PCM, TCM, and the battery energy control module (BECM) stay on, until the power down sequence is complete. The PCM and TCM stay powered by controlling their own dedicated power relays. The BECM is powered directly from the low voltage battery which permits wake-up function when the vehicle is off. During the power down sequence the TCM:

• requests the PCM to cut power to the injectors and ignition coils (engine shut down).

• disables the high voltage inverters.

• requests the BECM to disable the DC/DC converter.

• requests the BECM to open the high voltage contactors.

• discharges the high voltage inverter capacitors. • opens the TCM power relay.

If the power down sequence does not execute correctly, it is considered an abnormal shut down which may result in the PCM, the TCM and the BECM storing DTCs.

 

Power Up Sequence

The TCM conducts a power up sequence every time the ignition is turned from the OFF to the START position, if the gear selector is in PARK or NEUTRAL. During the power up sequence the TCM:

• initializes and begins controller area network (CAN) communications with the PCM and the BECM.

• requests the BECM to close the high voltage contactors.

• illuminates the green ready indicator indicating the vehicle is ready to drive in electric, gasoline,

or a combination of electric and gasoline modes.

• if required, requests the PCM to start the internal combustion engine. The internal combustion engine will not start if the gear selector is in NEUTRAL. The internal combustion engine starts if it is required for cabin heating, windshield defrost or the outside temperatures are low. The internal combustion engine also starts if the high voltage battery charge is low.

If a concern is detected during the power up sequence, the TCM may initiate LOS mode and store a DTC.

Edited October 18, 2015 by GrySql

[Texasota]

Glad to see classes have resumed. ;)

 

I haven't given much thought to the power down sequence but I have wondered what was going on during the power up sequence since there is the noticeable time lag from when you turn the key to the "ready to drive" message. I was familiar with almost all of the acronyms but had to lookup LOS (Limited Operating Strategy) in our acronym decoder thread. Very informative, GrySql.

 

Will there be quizzes or exams?

[GrySql]

Glad to see classes have resumed. ;)

Will there be quizzes or exams?

LOL...

Nope, information only for those that are interested.

This car is an absolute technical marvel.

[DeeCee]

This car is an absolute technical marvel.

Agree!!

 

You must have had a quiet Christmas to be able to post this info today. Anyway, much appreciated.

[garymkrieg]

So the question is will the ICE start if the car is in neutral and cabin heat is called for due to low outside temperature? If not then under those conditions it would mimic a Go Time pre-condition of the cabin if you were plugged in.

Gary

[lolder]

No, the ICE will not start in neutral except in one rare instance, at least in the Gen II 2010-12s. If you are coasting down a long hill in "N" and gain speed from below the max 47 mph EV speed to above, the ICE will start ( or be motorized, it's hard to tell ) so as to keep MG1 rpm below limits. MG1 is the motor-generator connected to the center "Sun" gear of the planetary gear. It controls the transmission power splitting, charges the HVB and starts the ICE. It is the heart of everything.

[GrySql]

So the question is will the ICE start if the car is in neutral and cabin heat is called for due to low outside temperature? If not then under those conditions it would mimic a Go Time pre-condition of the cabin if you were plugged in.

Gary

I read the above as the ICE will not start when the gearshift is in Neutral, it has to be in Park.

 

I went out to the garage this morning, it was 40F, and put the car in Accessory>Neutral>Start>Heat @ 80F.

The car sat there with the Green 'Ready to Drive' dash icon light on for 5 minutes, no heat coming out and no ICE startup, the HVB had about 1/3 capacity left when I got bored.

I then put the gearshift lever into Park and the ICE came on instantly. Not exactly scientific but something to think about.

 

BTW, after I get done with this hybrid software section I think we'll move to the eCVT section and explore that system. Seems to be a lot of general interest in how the eCVT actually moves the car.

Edited December 27, 2014 by GrySql

[garymkrieg]

Was your car plugged in when you did your test in the garage. What I was wondering is can I get the benefit of pre-conditioning using remote start while it is plugged in without the ICE starting?

 

Duh, never mind you don't have an Energi. It would be interesting to see if it would work that way. My car is not here with us while we are in Seattle, so I can't test it myself.

Edited December 27, 2014 by garymkrieg

[lolder]

If you leave the car in Accessory, the HVB will keep the car alive by charging the 12 vdc battery until the HVB gets to it's low shutoff limit when the HVB is disconnected. The 12 vdc battery will power things until it dies. The car is then dead until you jump the 12 vdc. It may take a few minutes for the dead 12 vdc to come up enough for the computers to allow the HVB to be connected again. The HVB will be below normal charge level but will be enough to start the ICE. The HVB will recharge in a few minutes but the 12 vdc will take much longer and you should probably put an automatic charger on it overnight. You probably haven't done the 12 vdc much good and it's life is probably shortened by such an event ( BT,DT ).

Edited December 27, 2014 by lolder

[Texasota]

BTW, after I get done with this hybrid software section I think we'll move to the eCVT section and explore that system. Seems to be a lot of general interest in how the eCVT actually moves the car.

A syllabus! Great idea, GrySql. We'll know what to look forward to in the next sessions!