Auto Start/Stop FORScan Issue on 2019

[FastEddie]

I have a Forscan question I hope someone can help me with. Will Forscan work on a 2019 Navigator? I have a 14 and a 18 Raptor and a 19 Navigator. Im not familiar with Forscan so Im wondering if there are different programs for the different vehicles? I had tolerated the auto stop-start on the 18 until recently just unplugging the trailer plug under the dash and all is fine. But this 19 Navigator has pushed me over the edge. It has the piano key shift and is more aggravating. When I pull into the garage to park I stop, the motor shuts off, hit the PARK piano key, the motor restarts, then hit the stop button to kill the engine. Really wares me out. I know you can just hit the stop ignition button and it will go to park but just doesn't seem right not physically putting it in PARK. May have to invest in Forscan for the Navigator.
Thanks for any help you can provide.

yes

 

[MAMiller44]

hi
I seen a YouTube video on this. the guy said it needs to be disabled in three locations.the switch, the dash and in the actual computef

Correct. For anyone who runs into this issue in the future. What I did was only disable the feature, and the switch. It still

I have a Forscan question I hope someone can help me with. Will Forscan work on a 2019 Navigator? I have a 14 and a 18 Raptor and a 19 Navigator. Im not familiar with Forscan so Im wondering if there are different programs for the different vehicles? I had tolerated the auto stop-start on the 18 until recently just unplugging the trailer plug under the dash and all is fine. But this 19 Navigator has pushed me over the edge. It has the piano key shift and is more aggravating. When I pull into the garage to park I stop, the motor shuts off, hit the PARK piano key, the motor restarts, then hit the stop button to kill the engine. Really wares me out. I know you can just hit the stop ignition button and it will go to park but just doesn't seem right not physically putting it in PARK. May have to invest in Forscan for the Navigator.
Thanks for any help you can provide.

A quick google search leads me to believe it operates very similarly to F150 programming. It’s real easy to use and as long as you back up your original files before messing with anything you can always revert back to the original later. There’s numerous YouTube videos explaining how to properly create backups. I backup after every individual modification I make to it, so I have all those snapshots in time to revert back to if I wanted.

 

[4rdFan]

I disagree with the item #2 where you state the alternator will never be in a free spin mode.

As an electronics technician, I can assure you that the alternator's job is to ALWAYS charge the battery and supply all of the electrical power needs of the vehicle.
To make sure I wasn't passing on bad info, I checked with a buddy of mine who was a Ford master tech and he confirmed what I learned in electronics school.

In modern Alternators the rotor's magnetic field is produced by a field coil electromagnet. Alternators use a rotor winding which allows control of the alternator's generated voltage by varying the current in the rotor field winding.

A voltage regulator (which is NOT the BMS) controls the field current of the electromagnet to keep output voltage constant. If the output voltage from the stationary armature coils drops due to an increase in demand or slower RPM, more current is fed into the rotating field coils through the Voltage Regulator. This increases the magnetic field around the field coils which induces a greater voltage in the armature coils. The output voltage is then brought back up to its original value.

This is why an alternator can and will produce the same output voltage at any RPM. Slower RPM, the voltage regulator increases the current to the electromagnet, maintaining the set voltage. Higher RPM, the voltage regulator reduces the current to the electromagnet to maintain the set voltage.

According to my buddy, Ford introduced the BMS when vehicles started using the Auto Start/Stop (A.S.S.) systems. The BMS's job is to reduce the load on the electrical system (if needed) when the truck turns off when the A.S.S. engages at a stop, in order to protect the battery from discharging too much and ensure the truck has enough battery power to restart when you release the brake.

Yes, I totally agree with how you described alternator function. However, the alternator does not always provide output. It varies with electrical load management (see BCM statement below). I was wrong on using the term "free spin" as this implies the alternator is disconnected or not working. According to Ford PTS manual: The BCM calculates and sends the set value needed for the generator (alternator) charging voltage via the HS-CAN to the PCM. And in turn, the PCM commands charging system output to the generator (alternator). Disabling BMS defaults the PCM charging system output to a set, constant value.

 

[Johndeere99]

yes

Thanks

 

[Johndeere99]

Correct. For anyone who runs into this issue in the future. What I did was only disable the feature, and the switch. It still

A quick google search leads me to believe it operates very similarly to F150 programming. It’s real easy to use and as long as you back up your original files before messing with anything you can always revert back to the original later. There’s numerous YouTube videos explaining how to properly create backups. I backup after every individual modification I make to it, so I have all those snapshots in time to revert back to if I wanted.

 

[Johndeere99]

Thanks

 

[4rdFan]

The PCM charging system output is ALWAYS a constant value which is between 13 and 14volts. You can watch your voltage in the information display and you will see it will stay constant NO MATTER WHAT THE LOAD or RPM. The ONLY time this will not be constant is if there is a problem with your charging system OR you overload the capacity of the charging system.

Don't confuse the BCM with the BMS.

According to a Ford master tech, the BMS is there ONLY because of the A.S.S. The BMS's (IF EQUIPPED as stated by Ford) only function is to protect the battery from excessive power drain when the vehicle SHUTS OFF while stopped. THAT'S IT! It has NO OTHER PURPOSE. The BMS's ONLY job is to make sure that when the A.S.S. engages and the truck shuts off, that the battery isn't drained beyond the point where the truck cannot quickly restart.

I will leave this here and we can make our own conclusions about it. I'm just presenting information that I see:

 

[blwn]

The PCM charging system output is ALWAYS a constant value which is between 13 and 14volts. You can watch your voltage in the information display and you will see it will stay constant NO MATTER WHAT THE LOAD or RPM. The ONLY time this will not be constant is if there is a problem with your charging system OR you overload the capacity of the charging system.

Don't confuse the BCM with the BMS.

According to a Ford master tech, the BMS is there ONLY because of the A.S.S. The BMS's (IF EQUIPPED as stated by Ford) only function is to protect the battery from excessive power drain when the vehicle SHUTS OFF while stopped. THAT'S IT! It has NO OTHER PURPOSE. The BMS's ONLY job is to make sure that when the A.S.S. engages and the truck shuts off, that the battery isn't drained beyond the point where the truck cannot quickly restart.

What you're saying about the constant voltage is true if the BMS is disabled. When BMS is enabled it will vary output as stated by 4rdFan.

Also, your master tech is incorrect. BMS has been around at the very least since the 13+ trucks (No A.S.S.) although there are similar threads there about the benefits/risks of disabling BMS. I don't think you're going to have any issues disabling BMS based on the many people that already have, just be mindful of running it down if you leave accessories on all the time.

 

[FL4x4]

BMS began showing up in 2011 as a system to monitor the condition of the battery. The BMS detects when the battery is failing or getting weak. And that's still it's job today.

The BMS establishes a base line for the battery when the vehicle is off (BMS needs 8hrs of vehicle undisturbed off time to establish the base line of the battery).

Once the BMS establishes the baseline of the battery, it can then detect when the battery is getting weak overtime. This is especially important for the A.S.S. feature because the starting of the vehicle is the BIGGEST draw on the battery. Couple that draw with accessories running while the engine is off and that's an even bigger load on the battery when the starter engages.

Turn your truck on and off multiple times in a short period of time, the battery doesn't get enough time to fully recharge.

Cycle multiple heavy loads (Starting the engine) over and over and it wears on the battery.

Therefore, we have the BMS which monitors the health of the battery and will stop the A.S.S from engaging if the battery isn't fully charged or is getting weak.

The BMS does not determine voltage output of the alternator. The PCM does. PCM tells the voltage regulator (which is built into the alternator) what voltage to output and maintain.

If the PCM tells the voltage regulator to output 14volts that's what the alternator does. Turn off all of your accessories and you get 14volts. Turn on ALL the accessories including all of your added lights and you'll still get 14volts, but the current output of the alternator with a full load is increased to supply power for the additional load to keep the system at 14volts. It's Ohm's law.

 

[blwn]

BMS began showing up in 2011 as a system to monitor the condition of the battery. The BMS detects when the battery is failing or getting weak. And that's still it's job today.

The BMS establishes a base line for the battery when the vehicle is off (BMS needs 8hrs of vehicle undisturbed off time to establish the base line of the battery).

Once the BMS establishes the baseline of the battery, it can then detect when the battery is getting weak overtime. This is especially important for the A.S.S. feature because the starting of the vehicle is the BIGGEST draw on the battery. Couple that draw with accessories running while the engine is off and that's an even bigger load on the battery when the starter engages.

Turn your truck on and off multiple times in a short period of time, the battery doesn't get enough time to fully recharge.

Cycle multiple heavy loads (Starting the engine) over and over and it wears on the battery.

Therefore, we have the BMS which monitors the health of the battery and will stop the A.S.S from engaging if the battery isn't fully charged or is getting weak.

The BMS does not determine voltage output of the alternator. The PCM does. PCM tells the voltage regulator (which is built into the alternator) what voltage to output and maintain.

If the PCM tells the voltage regulator to output 14volts that's what the alternator does. Turn off all of your accessories and you get 14volts. Turn on ALL the accessories including all of your added lights and you'll still get 14volts, but the current output of the alternator with a full load is increased to supply power for the additional load to keep the system at 14volts. It's Ohm's law.

Thanks for clearing that up. Do you have any information on the strategies used by the PCM to adjust the voltage? I was under the impression the BMS system is one of the factors it uses to determine what voltage to have the regulator output. Without knowing the state of charge it tries to maintain a consistent voltage, which I thought I read it was 13.5v somewhere