2023.5+ Cooling System Redesign and Larger 7 kW Heater

[Mach-Lee]

I was asked to make a post about the changes made to the thermal systems in 2023.5 models and later. They include:

• PTC heater was upgraded from 5 kW to 7 kW on models with LFP pack (nominal continuous output, peak output may be slightly higher in some situations)
  • New LFP pack is more sensitive to cold temps and requires more heating than NCM
• Glycol cooling is now a single system with three combined circuits rather than two separate systems (single coolant bottle instead of two coolant bottles)
• Addition of two 5-port valves allow excess heat to be utilized for battery heating (rather than being wasted)
• Removal of one coolant pump on base AWD models
• New on-board AC charger from a different supplier, has different hookup locations

Here's what the new cooling system looks like. Warning, these might give you a headache if you're not an engineer that deals with complex systems.

Base AWD:

Spoiler: Base AWD Component # Key

1 — Radiator
2 — Radiator vent hose
3 — Degas bottle lower hose
4 — Degas bottle cap
5 — Degas bottle
6 — Cabin coolant heater outlet hose
7 — Cabin coolant heater inlet hose
8 — High voltage battery coolant cooler
9 — High voltage battery coolant cooler inlet hose
10 — High voltage battery coolant cooler outlet hose
11 — Cabin coolant heater
12 — Cabin heater coolant pump
13 — Cabin heater coolant pump outlet hose
14 — High voltage battery coolant diverter valve inlet hose
15 — High voltage battery coolant diverter valve
16 — Cabin heater coolant pump inlet hose
17 — Heater core outlet hose
18 — Radiator lower hose
19 — High voltage battery coolant pump inlet hose
20 — High voltage battery coolant pump
21 — Motor electronics coolant pump
22 — Radiator upper hose
23 — High voltage battery radiator coolant diverter valve
24 — DC/DC inlet hose
25 — SOBDM (Secondary On-Board Diagnostic Control Module A)
26 — SOBDM inlet hose
27 — Front electric drive assembly
28 — High voltage battery coolant inlet hose
29 — DC/DC (Direct Current/Direct Current converter control module)
30 — DC/DC outlet hose
31 — High voltage battery radiator coolant diverter valve inlet hose
32 — Secondary inverter system controller [SOBDMB] inlet hose
33 — Secondary inverter system controller [SOBDMB] outlet hose
34 — Secondary inverter system controller [SOBDMB (Secondary On-Board Diagnostic Control Module B)]
35 — Heater core hose assembly
36 — High voltage battery coolant outlet hose
37 — Heater core
38 — High voltage battery coolant hose assembly
39 — High voltage battery plates
40 — Rear electric drive assembly lower coolant hose assembly
41 — Inverter system controller [SOBDMC (Secondary On-Board Diagnostic Control Module C)]
42 — Inverter system controller [SOBDMC] outlet hose
43 — Inverter system controller [SOBDMC] inlet hose
44 — Rear electric drive assembly oil cooler
45 — Rear electric drive assembly oil cooler outlet hose

Spoiler: Operating Modes

Note: I figured these out, not Ford. There may be errors.

Cabin heat: 11, 6, 35, 37, 35, 17, 14, 15, 16, 12, 13, 7
Motor/Electronics cooling: 1, 18, 21, 26, 25, 24, 29, 30, 40, 43, 41, 42, 44, 45, 40, 32 [(34, 33),(27, 33)], 23, 22
Battery heat: 11, 6, 35, 37, 14, 23, 19, 20, 28, 38, 39, 38, 36, 15, 16, 12, 13, 7
Battery cool: 8, 9, 14, 23, 19, 20, 28, 38, 39, 38, 36, 15, 10
Waste heat to battery: 25, 24, 29, 30, 40, 43, 41, 42, 44, 45, 40, 32 [(34, 33),(27, 33)], 23, 19, 20, 28, 38, 39, 38, 36, 15, 14, 23, 18, 21, 26
Waste heat to battery + cabin: 25, 24, 29, 30, 40, 43, 41, 42, 44, 45, 40, 32 [(34, 33),(27, 33)], 23, 19, 20, 28, 38, 39, 38, 36, 15, 16, 12, 13, 7, 11, 6, 35, 37, 35, 17, 14, 23, 18, 21, 26

Cabin heat, Battery cool, and Motor/Electronics cooling should be able to operate simultaneously and independently of each other since they have their own pumps. Such as while DC charging.

It is now a single system with one coolant bottle (4). Larger PTC heater is shown (11). The key addition was a pair of 5-port valves (15 and 23) that allows coolant to flow to many destinations. The left 5-port (23) is focused on motor electronics cooling and battery heating/cooling. The right 5-port (15) is focused on cabin heating and coolant chilling. There are three loops within the system that can be combined or separated by the 5-port valves. These loops are the high voltage battery circuit, cabin heater circuit, and a powertrain electronics circuit.

A huge improvement here is the utilization of waste heat generated by the motor electronics and charger. On first-generation Mach-E's, the waste heat from AC charging and the motors/inverters can only be dissipated to the radiator. This heat is effectively lost to the surroundings. The new design allows the charger/motor waste heat to be sent to the battery pack instead of the radiator. This can provide a huge improvement to battery temperatures in winter conditions, and also opens up the possibility of heating the battery pack with the motors instead of the PTC heater for additional output (like Tesla and Rivian do). This should also increase the efficiency of the vehicle in cold conditions.

In the old design, 10% of the energy you use for charging is completely wasted. If you AC charge all night, the motors and radiator will be warm. This heat will quickly dissipate to the surroundings while driving. With the new design, this 10% of energy can be used to warm up the battery pack for free. Therefore in the morning you will have a warm battery pack, which means more range and less energy used for departure time preconditioning.

GT:

Spoiler: GT Component # Key

1 — Radiator
2 — Radiator vent hose
3 — Degas bottle lower hose
4 — Degas bottle cap
5 — Degas bottle
6 — Cabin coolant heater outlet hose
7 — Cabin coolant heater inlet hose
8 — High voltage battery coolant cooler
9 — High voltage battery coolant cooler inlet hose
10 — High voltage battery coolant cooler outlet hose
11 — Cabin coolant heater
12 — Cabin heater coolant pump
13 — Cabin heater coolant pump outlet hose
14 — High voltage battery coolant diverter valve inlet hose
15 — High voltage battery coolant diverter valve
16 — Cabin heater coolant pump inlet hose
17 — High voltage battery coolant pump inlet hose
18 — Radiator lower hose
19 — Motor electronics coolant pump
20 — High voltage battery coolant pump
21 — Motor electronics coolant pump - GT
22 — Motor electronics coolant pump - GT outlet hose
23 — Radiator upper hose
24 — High voltage battery radiator coolant diverter valve
25 — SOBDM (Secondary On-Board Diagnostic Control Module A)
26 — Front electric drive assembly oil cooler outlet hose
27 — Front electric drive assembly oil cooler inlet hose
28 — Front electric drive assembly oil cooler
29 — Secondary inverter system controller [SOBDMB (Secondary On-Board Diagnostic Control Module B)]
30 — DC/DC (Direct Current/Direct Current converter control module)
31 — DC/DC inlet hose
32 — Secondary inverter system controller [SOBDMB] inlet hose
33 — Rear electric drive assembly coolant outlet hose
34 — Rear electric drive assembly coolant hose assembly
35 — Heater core outlet hose
36 — High voltage battery coolant outlet hose
37 — High voltage battery coolant inlet hose
38 — Heater core hose assembly
39 — Heater core
40 — High voltage battery coolant hose assembly
41 — High voltage battery plates
42 — Rear electric drive assembly lower coolant hose assembly
43 — Inverter system controller [SOBDMC (Secondary On-Board Diagnostic Control Module C)]
44 — Inverter system controller [SOBDMC] outlet hose
45 — Inverter system controller [SOBDMC] inlet hose
46 — Rear electric drive assembly oil cooler
47 — Rear electric drive assembly oil cooler outlet hose

The GT functions similar to the base AWD, but with one additional cooling pump (21) added for the larger front motor.

RWD:

Spoiler: RWD Component # Key

1 — Radiator
2 — Radiator vent hose
3 — Degas bottle lower hose
4 — Degas bottle cap
5 — Degas bottle
6 — Cabin coolant heater outlet hose
7 — Cabin coolant heater inlet hose
8 — High voltage battery coolant cooler
9 — High voltage battery coolant cooler inlet hose
10 — High voltage battery coolant cooler outlet hose
11 — Cabin coolant heater
12 — Cabin heater coolant pump
13 — Cabin heater coolant pump outlet hose
14 — High voltage battery coolant diverter valve inlet hose
15 — High voltage battery coolant diverter valve
16 — Cabin heater coolant pump inlet hose
17 — Heater core outlet hose
18 — Radiator lower hose
19 — High voltage battery coolant pump inlet hose
20 — High voltage battery coolant pump
21 — Motor electronics coolant pump
22 — Radiator upper hose
23 — High voltage battery radiator coolant diverter valve
24 — DC/DC inlet hose
25 — DC/DC (Direct Current/Direct Current converter control module)
26 — SOBDM (Secondary On-Board Diagnostic Control Module A)
27 — SOBDM inlet hose
28 — High voltage battery coolant inlet hose
29 — DC/DC outlet hose
30 — High voltage battery radiator coolant diverter valve inlet hose
31 — Rear electric drive assembly coolant outlet hose
32 — Heater core hose assembly
33 — Heater core
34 — High voltage battery coolant outlet hose
35 — High voltage battery coolant hose assembly
36 — High voltage battery plates
37 — Rear electric drive assembly lower coolant hose assembly
38 — Rear electric drive assembly oil cooler
39 — Inverter system controller [SOBDMC (Secondary On-Board Diagnostic Control Module C)]
40 — Inverter system controller [SOBDMC] outlet hose
41 — Inverter system controller [SOBDMC] inlet hose
42 — Rear electric drive assembly oil cooler outlet hose

RWD is extremely similar to base AWD, just without the branch in the loop for the front motor.

Old Coolant Systems for comparison

5-port Coolant Diverter Valve:

The electrified powertrain cooling system use 5-port valves that have the capability to regulate, switch, mix or split coolant flow output to components of the system as needed for desired cooling or heating. The desired coolant flow is controlled by the SOBDM , SOBDMC , SOBDMB and PCM calibration as determined by input from the temperature sensors of the components within the electrified drivetrain cooling system. These components include:

• Electric drive assemblies
• High voltage battery
• SOBDM
• SOBDMC
• SOBDMB
• DCDC
• Cabin heater coolant pump

The 5-port valve uses rotary valves internal to the housing to adjust coolant flow. These valves are not serviceable separate from the 5-port valve. The 5-port valve is serviced as an assembly.

7 kW PTC Cabin Heater (LFP only):

The heater is thicker than before.

The positive temperature coefficient (PTC) cabin heater has been increased in size from 5 kW to 7 kW on LFP pack models, providing 40% more heat output. The previous 5 kW models ran out of heat around 0ºF (-18ºC), the larger heater should hopefully allow the Mach-E to have heat down to -28ºF (-33ºC). It will also speed up battery heating times as well.

Note: 7 kW is the nominal heat output while cabin heating. PTC heaters can output more than nominal power in some situations, such as during battery heating with colder return temps (perhaps 8 kW). The output may briefly peak above 10 kW when first cycled on. But this is still considered a 7 kW nominal heater.

And before someone asks, I don't think the new heater can be retrofitted. It's physically larger and may not fit in old plumbing design. There will likely be issues with software control as well.

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[Mach-Lee]

If someone has a 2023.5 with a scan tool, we should test whether the motors are able to heat the battery pack for additional output. Navigate to a DC charger <19 miles while stationary, and check HV battery power and coolant heater power. Test with HVAC on and off. If the HV battery power is much higher than the coolant heater power, then the motors are being used for heating in addition to the PTC heater. Seeing sustained draw from the HV battery above 10 kW would be good news.

 

[Jwolf91]

Have a 2023 purchased in December. How could I determine if car has this change?

 

[Mach-Lee]

Have a 2023 purchased in December. How could I determine if car has this change?

Look at the build month on the door jamb sticker. I think the changeover was July. So 07/2023 or later on the sticker?

 

[redgrandam]

If someone has a 2023.5 with a scan tool, we should test whether the motors are able to heat the battery pack for additional output. Navigate to a DC charger <19 miles while stationary, and check HV battery power and coolant heater power. Test with HVAC on and off. If the HV battery power is much higher than the coolant power, then the motors are being used for heating in addition to the PTC heater. Seeing sustained draw from the HV battery above 10 kW would be good news.

I will definity be doing this as soon as I can get the ‘HV battery power’ reading to work in car scanner. I don’t know if it’s a setting that changed with the newer models or if I just need a better Bluetooth OBD reader. It works with everything except the battery power.

 

[GarageWarrior2023]

Thanks @Mach-Lee !! This is awesome! Exactly what I was hoping to get a look at and learn.

I like the scavenging of motor heat. It did seem strange to me that the original design was a completely separate coolant loop. This new design is significantly more complex and seems to have more programmability with fine grain control to make adjustments/improvements over time.

 

[Mach-Lee]

I will definity be doing this as soon as I can get the ‘HV battery power’ reading to work in car scanner. I don’t know if it’s a setting that changed with the newer models or if I just need a better Bluetooth OBD reader. It works with everything except the battery power.

Can you figure it out with volts and amps?

 

[redgrandam]

Can you figure it out with volts and amps?

Maybe. I’ll have to look again what options are there probably next weekend.

 

[Homestead]

Thanks Mach-Lee.
I have a 2023 Premium AWD LFP built in Oct. No scan tools yet but never ran out of cabin heat
during the winter which is over here, supposed to 60F later this week in PNW.
Lowest temps were 13F in Jan. Did notice a big hit in range however during the cold spell.
We keep the cabin at 73F with seat heaters and steering wheel heater on as well.

Thanks for the info and glad we got the bigger heater.

 

[dwadj]

and still no heat pump ....

 

[Shayne]

It is good to know that they are moving forward. So from 5 to 7 KW and that should do it? A 40% increase. Two heaters independent of one another, each with there own job, would be a great solution. Both with the capacity to optimize of course.

EV tech basics is prefect for a commuter. If you do under 250 km a day you should be good in a LR battery to -25C no problems. You plug in cheap at home each night and it does it thing like your smart phone. 10% to 90% home charge here costs $13.00 CAD for 330 km in the summer 20C's. Add to that they are quick and I think when the bugs get ironed out and they come down in price a bit they may make a lot of sense for many. Better get that grid up.

 

[Mache_Nor]

and still no heat pump ....

With you here. They could really save a lot of energy here while still keeping it toasty / cold when needed. Let me remind you that most heat pumps nowadays works well to as low as -20C, and often it is functional down to -30C (albeit at less efficiency).

 

[PaddaOnIce]

Where is the “door jam” sticker?

 

[redgrandam]

Where is the “door jam” sticker?

Open the drivers door and it is one of the stickers on the lower right. Not the one with the tire pressures, the manufacturer label. Looks like this:

 

[PaddaOnIce]

Ok in Europe (Norway) we don’t have such a sticker

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