Blinker hyperflash on dash screen only

[derichio02]

Hey gang,

So while installing a third brake light that has a taillight harness that grabs the reverse light I somehow triggered blinker hyper flash.

The peculiar part of it is that it’s only on the dash screen and is not actually happening at the light itself.

I have tried removing the harness that has the jumper and plugging the tail light back in. I also tried clearing all codes in Forscan. Lastly I tried removing the negative cable from the battery for an hour…

But the problem still persists. Any ideas?

Sponsored

 

[Dan-O]

Just a guess here, but after connecting your new light, maybe the system detected an issue with voltage causing a problem with a resistor for one of the LED lights. I’m not even sure if the Bronco lighting uses resistors for the LEDs or if it’s all controlled thru modules.

 

[Brian_B]

Just a guess here, but after connecting your new light, maybe the system detected an issue with voltage causing a problem with a resistor for one of the LED lights. I’m not even sure if the Bronco lighting uses resistors for the LEDs or if it’s all controlled thru modules.

Controlled in the module - you can set the BCM for either LED or Halogen rear bulbs and it adjusts what it expects accordingly without external resistors needed for LED. If it sees an incorrect resistance it will fast blink - although CHMSL doesn't have a turn signal so.... I dunno.

I was having a similar issue once upon a time and it ended up being a pinched wire for one of the turn signal lights that was starting to short out to chassis (my trailer hitch adapter has a cross wire that goes underneath the lower trim guard on the tailgate -- that wire). My fault entirely on that one.

 

[fordwrench91]

Good info above on the BCM LED lamp setting. One more thing worth checking: when you installed and then removed that harness tap, the BCM may have learned an incorrect lamp load state. In FORScan, go into BCM configuration and look for any rear lighting or lamp monitor settings - specifically anything related to rear turn signal lamp type. Verify they still match your stock setup. Also run a full module scan and look for any B-codes in the BCM related to rear lighting that came back after you cleared them. A marginal connection in that harness tap can cause the BCM to log a load fault even after the tap is removed, which keeps the dash indicator flashing without affecting the actual bulb. If you find a B-code pointing to a specific circuit, that narrows it down a lot.

 

[derichio02]

Good info above on the BCM LED lamp setting. One more thing worth checking: when you installed and then removed that harness tap, the BCM may have learned an incorrect lamp load state. In FORScan, go into BCM configuration and look for any rear lighting or lamp monitor settings - specifically anything related to rear turn signal lamp type. Verify they still match your stock setup. Also run a full module scan and look for any B-codes in the BCM related to rear lighting that came back after you cleared them. A marginal connection in that harness tap can cause the BCM to log a load fault even after the tap is removed, which keeps the dash indicator flashing without affecting the actual bulb. If you find a B-code pointing to a specific circuit, that narrows it down a lot.

I will check this out in the afternoon. I saw on an f150 forum that reloading as built values fixed it for some users experiencing this type of issue.

I do have the FP tune, not sure if restoration my BCM with my as built file with cause any issues with my tune? Has anyone done this?

 

[derichio02]

@Ducati1098 any knowledge of the effect of a BCM AsBuilt restore on the FP Tune?

 

[fordwrench91]

BCM as-built restore and an FP Tune are separate systems and shouldn't interfere with each other. BCM as-built only touches BCM-controlled features (lighting, door locking behavior, comfort/convenience features). An FP Tune lives in the PCM/TCM and controls fueling, boost, shift logic, etc. Restoring BCM as-built will not touch PCM calibration. The only crossover to watch for: if your FP Tune included any BCM-adjacent changes as part of a full tune package (some shops bundle PATS configuration or accessory timeout changes), those specific BCM settings would get overwritten by a restore. If you only have an engine/trans tune from FP with no BCM component, you're safe to restore BCM as-built without touching the tune.

 

[Ducati1098]

@Ducati1098 any knowledge of the effect of a BCM AsBuilt restore on the FP Tune?

Wont affect anything

 

[derichio02]

Well that didn’t work and made me update my tire size, relearn both PCM and AWD.

I hope that I did not kill my FP tune or Towing Programming that was added after that BCM backup.

Any thoughts on the programming killing either of those things @fordwrench91

 

[derichio02]

Also I did find an error code for a general electrical failure in the right tail light

 

[fordwrench91]

The BCM restore shouldn't have touched your FP Tune or towing programming — those live in the PCM/TCM, not the BCM. You may have needed to do the tire size relearn and AWD relearn because restoring BCM as-built reset some of the learned configurations the BCM holds (wheel speed calibration references), but that's expected and normal. Your FP calibration is untouched.

That B-code for right tail light electrical failure is the real clue here — that's almost certainly what's been driving the hyperflash on the dash all along. The BCM detected a load fault on that circuit and latched the fast-blink behavior. Clear the code and physically inspect the right tail light socket and wiring. Since you had a harness tap in that area, look for any damaged pins, a terminal that didn't fully seat back, or a wire that got nicked during the install. Even a high-resistance connection that passed a visual check can trigger a lamp monitor fault on the Bronco's BCM.

Sponsored