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2022 Ford F-450, Start Button DTC After Start Kill

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=147531
Printed Date: April 26, 2024 at 6:51 AM


Topic: 2022 Ford F-450, Start Button DTC After Start Kill

Posted By: overkillcarsec
Subject: 2022 Ford F-450, Start Button DTC After Start Kill
Date Posted: December 13, 2022 at 6:41 AM

I cut and rejoining a wire to the Push Button Start in this vehicle (intended to work as a starter kill via relay but changed my mind)). The button loom has 6 wires, two of which are Data. Now the ECU( or BCM) is flagging a Low Volatage detected code on the button and its not going away, in spite of resetting the ECU( or BCM).
I used an LED probe and DMM to check before cutting the power feed wire from the switch to the car. I am stuck with a very upset owner.
Fault code is P2534:00-2F | Ignition Switch On/Start Position Circuit Low | Continuous Memory DTCs .
I get how cutting the wire would have flagged the fault, but why is it still coming up after rejoining the wire? When Cut, no start signal. Once rejoined, car starts fine. But after a few goes flags the fault. Resetting clears the fault and after a few drives it flags as a fault again. I'm praying the ECU( or BCM) isn't fried. Any suggestions as to the cause and fix for this problem?


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OverkillCarSecurity



Replies:

Posted By: mgoetz74
Date Posted: December 14, 2022 at 3:39 PM
"I used an LED probe"- not good. you may have pulled to much resistance and fried the bcm. You should never be using anything other than a dmm on any car newer than 1998-2000 and up, maybe earlier. Ive seen installers blow air bags with those and short all kinds of stuff out over the years. Could always pull both + and - @ the battery and let it set for 5 minutes then touch both together to make sure it drains the caps in the truck. me personally...bcm

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33 years as a installer now just a retired old guy. Favorite thing to install/topic are remote starts/car alarms. Stop using test lights!!!




Posted By: overkillcarsec
Date Posted: December 14, 2022 at 10:13 PM
Thank you for your feedback :) In principle, I agree. Although the whole idea of using an LED probe is the current is capped at around 10-15mA making it safe. Admittedly, sending 12v down a possibly 5v digital line even at 10mA is a worry (and why I do carry and use a DMM sometimes) but untill now I have not had a problem. However it was the flickering LED probe showing 2 out of 6 wires at the Push to Start button to be data lines...
As for the PCM ( I believe thats what its called in this case).. 2022 Ford F450, yes the battery disconnect reset has been done, more than once and the flag returns after a few short drives indicating there is a fault somewhere still.

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OverkillCarSecurity




Posted By: mgoetz74
Date Posted: December 15, 2022 at 9:34 AM
you can use what you want, to each there own. Everyone always says "I have never had a problem" but I don't have to pay for the damages I guess. It only takes one $2000+ bcm to learn a lesson I guess. Could always try a different code reader. I have had codes I couldn't reset with my expensive one but could with a cheap $40 one from harbor freight. good luck

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33 years as a installer now just a retired old guy. Favorite thing to install/topic are remote starts/car alarms. Stop using test lights!!!





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