How long has Ford been using an electric secondary water pump for cabin heat?

[TheSleepyWeasel]

My 2020 Ranger is in the shop (private facility, my local Ford dealer service department is full of clowns). Last week the A/C quit blowing cold in 100+ degree Texas heat. The guys working on it said an electric "Cabin Heater Coolant Pump" failed, triggering a computer response shutting off the A/C.

I had to call the guy at the shop to be sure my wife hadn't garbled the message. Every previously owned vehicle of mine has used the main water pump to send coolant to the heater core. Of course my first car was built in early 1964 and had room enough for me to sit in the engine compartment and work on it.

Any idea when Ford started using these and why? I Googled it (specifically for the Ranger) and got diagrams of their placement in a whole boatload of models including a Lincoln or two.

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[airline tech]

It’s used when ASS is activated - engine shut off - electric pump keeps hot coolant flowing through the heater core-thus keeping cab warm. (Cold Weather)
So I think in your case - lost ac cooling - pump was constantly running- thereby heating the cold air

 

[airline tech]

Cabin Heater Coolant Pump

The cabin heater coolant pump is available on vehicles equipped with Auto Start - Stop feature only. The cabin heater coolant pump provides coolant to the heater core whenever the HVAC system requests heat and the vehicle is in auto start-stop mode. Refer to the Owner's Literature, Unique Driving Characteristics for full auto start-stop enabling/disabling information.

The PCM sends a PWM signal to the cabin heater coolant pump based upon the:

• Auto Start-Stop mode enabled
• HVAC system temperature control setting (requesting heat)
• Ambient air temperature
• Engine coolant temperature
• Engine Revolutions Per Minute (RPM)
• Vehicle speed

 

[Loweredon33s]

Gonna blow minds when you find out that the transmission has an electric pump for a similar reason.

 

[airline tech]

Gonna blow minds when you find out that the transmission has an electric pump for a similar reason.

True - I thought about including that info as well

 

[TJC]

The more complicated the plumbing, the easier it is to stop it up! It is simply one more point of failure.



If I disable ASS, does it disable the pumps as well?

 

[TJC]

Gonna blow minds when you find out that the transmission has an electric pump for a similar reason.

The electric pump for coolant or the transmission fluid?

 

[ctechbob]

The electric pump for coolant or the transmission fluid?

For the fluid. It is to keep pressure on the system so you don't slip clutches while you're waiting on the main pump to pressurize the system on a restart.

 

[TheSleepyWeasel]

Cabin Heater Coolant Pump

The cabin heater coolant pump is available on vehicles equipped with Auto Start - Stop feature only. The cabin heater coolant pump provides coolant to the heater core whenever the HVAC system requests heat and the vehicle is in auto start-stop mode. Refer to the Owner's Literature, Unique Driving Characteristics for full auto start-stop enabling/disabling information.

The PCM sends a PWM signal to the cabin heater coolant pump based upon the:

• Auto Start-Stop mode enabled
• HVAC system temperature control setting (requesting heat)
• Ambient air temperature
• Engine coolant temperature
• Engine Revolutions Per Minute (RPM)
• Vehicle speed

Thanks, the Start/Stop never occurred to me as the reason for these things.

What are the odds they're smart enough to run an electric oil pump to the turbocharger for the same reason?

 

[airline tech]

The more complicated the plumbing, the easier it is to stop it up! It is simply one more point of failure.



If I disable ASS, does it disable the pumps as well?

It is intended to operate only when ASS is activated - so if ASS never kicks in- it should not run

 

[TJC]

That's good news!

 

[TJC]

My 2023 CX-5 has variable high speed electric motors controlling the Intake Variable Valve Timing! They control the intake valve speed and have been extremely reliable.

So there is a place for these types of applications, as long as the manufacturer uses high quality parts.

 

[got3fords]

I wondered why the AC seemed to blow cool air for several seconds when the ASS shut the engine off, is that what we're talking about?

 

[dtech]

My 2023 CX-5 has variable high speed electric motors controlling the Intake Variable Valve Timing! They control the intake valve speed and have been extremely reliable.

So there is a place for these types of applications, as long as the manufacturer uses high quality parts.

yeah those types of pumps for the cabin heat are becoming commonplace on newer models, I can't speak to the tranny but what ctechbob says makes sense. Hopefully the tranny pump is reasonably easy to access or bulletproof if there is such a thing. So another thread counted the no of heat exchangers on the Ranger - think it was 5 or more, wonder how many electric pumps are involved - abs, tranny, cabin, in tank fuel, maybe vacuum brake , come to mind.

 

[myothercarizahearse]

so then is the pump also deleted for the lucky few with the ASS delete from the chip shortage? IIRC it was a $50 refund. how much does the pump cost?

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