Power Reduced To Lower Engine Temperature

[JWmson]

I’ve read through posts/forums/Google till I’m blind, and maybe I missed it, but…
has anybody actually found the cause and verified fix for this issue?

I keep getting it while running unloaded at 60-70 mph down the freeway in 65-85 degree weather. It’s intermittent, with no consistency, but the digital temp is usually in the 208-220 range if it goes off. Normally, I see 190-198 on these same routes. Truck is a 2022 with 13k miles on it. All fluids (etc.,etc,etc) are good, and I run 92 octane fuel. I’m baffled and wondering if the louvers in front of the radiator may not be operating correctly??? This truck is certainly not suited for hauling/trailering if this can’t be resolved.

If you’ve actually had success in addressing this, please post here under this specific heading. Thank you.

Update: Got an appt. At Tonkin Ford in Hillsboro, OR with only a one week wait. They confirmed the diagnosis and said they would have the new part installed and be ready for pick up in two days!

Update #2: No go. Apparently the parts they had were for the nipple replacement TSB. Gave me the truck back with a 6-8 month back order on the heat exchanger. This service dept was super courteous, stuck to the scheduling, and seemed to be a well run shop, though.

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[Powerboost22]

You likely need to replace you exhaust heat exchanger. Just got done with this, same issue. Engine temp is fine but the secondary cooling loop temp is off cause of the h/e and will start throwing codes with that warning message.

 

[Snakebitten]

As @Powerboost22 stated, this isn't your engine (coolant) actually overheating and is not reflective of the trucks tow-worthyness.

Rather it's a malfunction of that big WART Ford mounted on the midpipe of your exhaust.

 

[Samson16]

You likely need to replace you exhaust heat exchanger. Just got done with this, same issue. Engine temp is fine but the secondary cooling loop temp is off cause of the h/e and will start throwing codes with that warning message.

So, engine coolant fluid temperature is normal, but the "secondary cooling loop" that exists to cool the HVB and associated components is "off cause of the h/e and will start throwing codes" yet the heat exchanger is part of the primary coolant loop?

That is all kinds of confusing.

The heat exchanger is a known high failure item and it is common for it to leak and/or throw fault codes.

Is that what you and Snake mean? I thought it had been confirmed that the heat exchanger is there to warm up the engine quickly to facilitate electric idle and operation advantages?

I could be wrong...

 

[Snakebitten]

I am not sure that it has anything to do with the Hybrid/Electric coolant loop or temps. It could be, but derating the internal combustion engine doesn't make much sense in that scenario.

Since we have seen this issue be associated with the Exhaust Heat Exchanger malfunctioning and it triggers a coolant temperature alert that's theoretical, rather than actual.

Or put another way, code exists for the circumstance of the heat exchanger malfunction, and that code triggers both the alert and the engine management response. But it appears that both the code and the response are actually preemptive to the condition they describe?

It's obviously not an alert driven by the engine coolant temperature sensor that reports to the instrument cluster. So I'm guessing it's an alert driven by sensors associated with the exhaust heat exchanger, but the engineers built in the verbiage of the alert and the engine management (pcm) response.

I think we've seen a fair number of examples of alerts and responses that could be described as "heavy handed" considering what the actual circumstances are that trigger them?

Like: Pull over immediately and call a wrecker to come fetch your truck. Or, if you'd rather, just wait a few minutes and everything will be back to normal.

 

[Powerboost22]

@Snakebitten
@Ford Motor Company

Anyone know if the h/e has been modified since the factory build or are we just replacing one defective part with a newer defective part?

Ideally I hope to keep this truck for a few years but I do high mileage, hopefully not replacing this every 25,000 miles..

 

[Snakebitten]

The part number of the Exhaust Heat Exchanger has changed for both wheelbases. So it's a "revised" part, but nobody knows exactly what was revised.

For the most common exhaust heat exchanger issue, a coolant leak, Ford wisely has made the coolant tubes a separate parts purchase, so no longer is the whole midpipe replaced. That was a huge waste of expense.
The tubes are $5 each.

But regarding the other issue that triggers the Engine Coolant Temperature alert, that's not something that can remedied with a simple parts swap.

 

[Ford Motor Company]

I’ve read through posts/forums/Google till I’m blind, and maybe I missed it, but…
has anybody actually found the cause and verified fix for this issue?

I keep getting it while running unloaded at 60-70 mph down the freeway in 65-85 degree weather. It’s intermittent, with no consistency, but the digital temp is usually in the 208-220 range if it goes off. Normally, I see 190-198 on these same routes. Truck is a 2022 with 13k miles on it. All fluids (etc.,etc,etc) are good, and I run 92 octane fuel. I’m baffled and wondering if the louvers in front of the radiator may not be operating correctly??? This truck is certainly not suited for hauling/trailering if this can’t be resolved.

If you’ve actually had success in addressing this, please post here under this specific heading. Thank you.

Hello! Could you privately message us with your VIN and the name and location of your Ford dealer so I can look into this warning message concern for you? Thank you!

 

[JWmson]

As @Powerboost22 stated, this isn't your engine (coolant) actually overheating and is not reflective of the trucks tow-worthyness.

It’s hilly where I live, and empty the derate pulled me down to 45mph. I can only imagine what adding an 8000 lb. trailer would do.

I was able to get a ForScan reading and had the following:
P237D- exhaust heat exchanger bypass valve’A’ control circuit low
P2C22- exhaust… valve ‘A’ position sensor circuit
Sounds like what you all are suspecting, right?

Thank you for the responses. I guess it’s time for a dealer visit.

 

[Snakebitten]

It’s hilly where I live, and empty the derate pulled me down to 45mph. I can only imagine what adding an 8000 lb. trailer would do.

I was able to get a ForScan reading and had the following:
P237D- exhaust heat exchanger bypass valve’A’ control circuit low
P2C22- exhaust… valve ‘A’ position sensor circuit
Sounds like what you all are suspecting, right?

Thank you for the responses. I guess it’s time for a dealer visit.

Yes, it's the more irritating of the 2 maladies you can experience with the exhaust heat exchanger.

Currently requires a full replacement of the assembly.

Either the servo itself is faulty, or the valve/flap is stuck open/closed. Similar to an HVAC blend door hanging up.

 

[Oxford_Powerboost]

Yes - due to the heat exchanger directly linked with those codes. The service manual shows codes for a temp sensor issue between inlet and outlet of exhaust heat exchanger - my hunch is that this power reduced issue is a reaction to the valve being stuck and allowing the exhaust to bring the heat exchanger temp too high. Your coolant isn’t getting too hot, but it might be getting locally too hot in the heat exchanger or the heat exchanger itself may be getting too hot.
I had the same issue, it does aggressively pull power back and is not related to the coolant temp displayed.

 

[Snakebitten]

Yes - due to the heat exchanger directly linked with those codes. The service manual shows codes for a temp sensor issue between inlet and outlet of exhaust heat exchanger - my hunch is that this power reduced issue is a reaction to the valve being stuck and allowing the exhaust to bring the heat exchanger temp too high. Your coolant isn’t getting too hot, but it might be getting locally too hot in the heat exchanger or the heat exchanger itself may be getting too hot.
I had the same issue, it does aggressively pull power back and is not related to the coolant temp displayed.

I don't think there's a more accurate and clearly stated summary of the issue.

 

[amschind]

The good news: Megaohm is working on a dongle that will plug into the heat exchanger wiring harness to disconnect this whole mess without throwing codes: the dongle will plug into the factory heat exchanger connector and mimic a working heat exchanger.

The bad news: the truck will throw a code when the engine tries to command the exchanger to heat the coolant and the in and out sensors show the same temperature. My proposed solution to this is ignore the code and get the truck inspected in the summer when it isn't trying to command coolant heating (thus it never knows that the temperatures WOULD be the same if it DID command coolant heating, or at least not until the fall).

My open question: would the "temperature not increased as expected" code put the truck into limp mode or simply put a CEL on your dash?

Final thought: building a bypass circuit for the coolant is easy, which allows you to completely remove the resonator/heat exchanger pipe section. All you need is some 3/8" heater hose, pipe clamps, a U-hose off amazon and some fiberglass pipe wrap (last part probably optional, but its close to the exhaust and will wreck your truck if it leaks).

 

[EcoOrBoost]

Yes - due to the heat exchanger directly linked with those codes. The service manual shows codes for a temp sensor issue between inlet and outlet of exhaust heat exchanger - my hunch is that this power reduced issue is a reaction to the valve being stuck and allowing the exhaust to bring the heat exchanger temp too high. Your coolant isn’t getting too hot, but it might be getting locally too hot in the heat exchanger or the heat exchanger itself may be getting too hot.
I had the same issue, it does aggressively pull power back and is not related to the coolant temp displayed.

This matches my experience. My truck had the same malady; the heat exchanger got hot enough to melt the wiring harness on the top of it and required replacing wiring as well.

 

[HammaMan]

The good news: Megaohm is working on a dongle that will plug into the heat exchanger wiring harness to disconnect this whole mess without throwing codes: the dongle will plug into the factory heat exchanger connector and mimic a working heat exchanger.

The bad news: the truck will throw a code when the engine tries to command the exchanger to heat the coolant and the in and out sensors show the same temperature. My proposed solution to this is ignore the code and get the truck inspected in the summer when it isn't trying to command coolant heating (thus it never knows that the temperatures WOULD be the same if it DID command coolant heating, or at least not until the fall).

My open question: would the "temperature not increased as expected" code put the truck into limp mode or simply put a CEL on your dash?

Final thought: building a bypass circuit for the coolant is easy, which allows you to completely remove the resonator/heat exchanger pipe section. All you need is some 3/8" heater hose, pipe clamps, a U-hose off amazon and some fiberglass pipe wrap (last part probably optional, but its close to the exhaust and will wreck your truck if it leaks).

If they were a little bit more quick on the design, they'd incorporate a relay that the driver can over-ride as desired

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