Multiple Warning Lights and DTCs

[wayne1948]

Mine did the same thing on my 2021 power boost. Check the wheel speed sensors. My left rear was bad. $20. Part.

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[Chaos150]

My 21 ecoboost is going through the same thing minus a few of your faults. Mainly the pre collision. Hill descent. Lane assist. Park aid. Service engine wrench. 4x4. Shift service. The fort time the dealer did updates. To what idk. Didn’t fix the issue. Then they replaced the steering wheel module. Didn’t fix anything. Now they are replacing the coax cable to the front camera. Still waiting for that supposed fix to happen.

 

[SWNEFordDude]

Had simular issue at the beginning of Sept, loss of connectivity to a bunch of modules.
Originally thought battery but did charging outside of vehicle and reset BMS.

Took to dealer and they said bad speed sensor after bricking ABS module. They were also doing axle recall and blamed the bolt on wiping out the speed sensor. Don't really think that was the case as the bolt wasn't sheared at the time.
They then ordered a wire harness that was on backorder. Took the truck at home due to previous issue where scratches on doors after leaving truck there for previous axle recall(before new design). I was told it was drivable other than ABS and other stuff not working.
After a couple weeks of not getting the part, I called the dealer and said the truck was down and I would be bring to them to sit until fixed. The brakes went to the floor when pressed before shifting into gear like a air bubble or low fluid when they were t-shooting the ABS issues.
The truck was parked away from other vehicles and brought in at night.
A few days later the harness magically came in and I got the call that it was ready.
Unfortunately I do not have the work order due to picking it up on a Saturday and the service guy wasn't in, so I can't tell you which harness was replaced.
Since then truck has been flawless.

Is there anyway you can reach out to the dealer and find out exactly what they did? I’m currently fighting the same issue potentially.

 

[Vinz Clortho]

Without knowing what DTC's were flagged, can only guess but this is what Perplexity identified based on your list of issues.


Low 12‑volt voltage or unstable ground: Ford’s service bulletin highlights that “Stop Safely Now,” “Check Engine,” and “Service Wrench” events can stem from voltage drops below 10 V at startup. These cause U‑code communication losses across control modules such as SOBDMC/BECM/ABS/PCM, and can cascade into multiple unavailable systems.

• Faulty auxiliary battery isolator (ML3Z‑14526‑B): A confirmed TSB (March 2023) details the isolator intermittently cutting power between the hybrid and auxiliary systems, causing DTC P2C44 and triggering numerous warning lamps. Ford’s fix is reprogramming the PCM and/or replacing the isolator.
• High Battery Junction Box (HVBJB) failure: Many owners report Ford replacing the HV battery junction box under warranty after “Stop Safely Now” and high‑voltage errors appeared with FordPass alerts. This box manages the HV circuit interlocks, and a fault interrupts high‑voltage communication and charging.
• Gateway Module A / network dropout: Later PowerBoosts have experienced U0293 or P1A43 codes in the BECM from gateway software faults that cut CAN communication. Ford issued SSM 52228 describing this, noting restarts may temporarily clear the issue.
• High‑Voltage battery or contactor fault: FordPass “High‑Voltage System Fault” messages and the truck’s shutdown behavior have been linked to a failing contactor inside the HV battery or internal sensor misreads, sometimes requiring battery replacement or recalibration.

I'd start by replacing the battery isolator. It's only about $65 and is connected to the positive terminal of the primary battery and can be replaced in a matter of minutes with basic hand tools.

I bought and replaced the battery isolator but it was unsuccessful. However, the code P1A43 did come up stating "Hybrid/EV Battery Contactor Request Signal Performance" so I am taking it to a 3rd dealer and will put emphasis in this code and the hybrid battery. Hopefully they will be able and willing to help more than the other 2.

 

[Vinz Clortho]

Mine did the same thing on my 2021 power boost. Check the wheel speed sensors. My left rear was bad. $20. Part.

I asked the first dealer if they checked them and they stated they were tested during the whole vehicle scan and they had no reason to believe they were faulty. Taking it to a 3rd dealer and will see what they say.

 

[Snakebitten]

I bought and replaced the battery isolator but it was unsuccessful. However, the code P1A43 did come up stating "Hybrid/EV Battery Contactor Request Signal Performance" so I am taking it to a 3rd dealer and will put emphasis in this code and the hybrid battery. Hopefully they will be able and willing to help more than the other 2.

That might be very helpful

It at least implies that you might just want to look for damaged (rodent?) harness or connectors?

 

[Snakebitten]

Additional information:

 

[Vinz Clortho]

Finally received my truck back after a long 8 weeks. After they replaced the restraint control module (no luck with lights) they found that the HV cable was chafing on the AC line, which they strongly believe is the issue (makes sense to me as well).

I don't know if I am missing a bracket which holds the HV cable off of the AC line or not but would some closed cell foam tape or something like that on the AC line help in the case? It should essentially stop the possibility of the HV cable vibrating and/or resting on the AC cable with its extreme temps.

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