BSM randomly/warming light

Since I had 4WP install rear steel bumper I’m getting randomly BSM disabled message along with yellow triangle warning light. The bumper is marketed as retaining BSM. Day after install while driving got the disabled warning, parked in garage overnight, next day back to normal. All good for next 10 days I get the disabled BSM message again. While driving message disappeared within an hour. No warning for next few days then get warning light, while driving I called shop was told come in now with warning light on. However while driving to shop warming light disappears. Shop inspected the connections on the actual BSM boxes in rear. The steel bumper has a plastic housing specifically for BSM signals to travel through the plastic. The fact that I had zero issues with BSM before install then logically the install caused an issue. It’s working as of today but there has been a pattern. Shop can only inspect the sensors and connections. Lastly I was told it’s a soft sensor code that’s not stored.

 

there is no telling, and you didn't include what bumper you bought, but since the system is radar and your issue is on/off, I wonder if it has more to do with the design and part of the bumper blocking the signal. I am also wondering if there is a dealer calibration for this system.
Just some random thoughts. I would link your exact bumper and see if someone else has firsthand experience with it.
Worse case scenario, you may be able to return this to stock and tell 4WP this is a safety issue.

 

1. i would check all the connections. there's usually multiple. make sure they're plugged in all the way, and no pins are bent/corroded.
2. i would verify no wires are pulled tight. sometimes tightly pulled wire will stress a connector and cause an intermittent connection issue.
3. the system might just need to be re-calibrated for the plastic thickness of the new bumper. different materials have different radar effects. same as using a stud finder on a wall.

 

I installed this bumper on my truck. It has become super sensitive to thinks as I back up. No BSM issues. During install, I noticed the wires are super tight and I could see connections being an issue.


I think @soundman98 was right on, checking wires & connections. Check connections, pull them apart clean and reconnect.

Top priority and easiest connection to check would be the bling spot monitor sensors. Theses are mounted on the sides under the plastic caps. Couple screws to take the plastic off. BSM sensors are notorious for getting super dusty and dirty. Disconnect the sensor and give them a good cleaning reconnect and see if that worked.

If that didn’t fix, check the remaining connections and wires. This would require getting under the truck and possibly taking the bumper off. Check to see how tight the wires are.

lastly, if all else fails take it back to 4wps and tell them what the Hill man. I didn’t need to recalibrate anything. Install was 100% bolt on.

 

This is the bumper installed

$1,000 4 Wheel Parts Factory Tacoma Rear Bumper - 61448W

https://www.4wheelparts.com/p/4-wheel-parts-factory-tacoma-rear-bumper-61448w/_/R-4WPBR-61448W

 

Yup, the 61448W is the one I installed on my taco.

 

I was told the wiring harnesses were updated to accommodate without stretching. Spoke with a representative at my local Toyota, was told it most likely needs to be recalibrated or repositioned. Since this bumper is marketed as BSM I requested 4WP pay the cost to recalibrate. I’m awaiting a response.

 

Update. Still getting random disabled BSM warning going on/off frequently. 4WP paid for recalibration at Toyota. A hard code present along with soft code. Both codes indicate replace both sensors. However the service manager doesn’t feel new sensors will correct issue. Was told it’s the bumper itself. 4WP doing the right thing and ordered another bumper to install. 4WP instructions specifically indicate both + and ~ terminals must be disconnected, if not the sensor could be damaged. I’m not sure how that would kill the sensors beyond a recalibration. Here is a link to 4WP own install instructions. Thoughts ?
https://www.4wheelparts.com/sku/4 Wheel Parts/standard/4WP61448W_INST.pdf

 

Thoughts are if the product claims to retain BSM functionality and they are throwing codes after the install, then something happened during the install. 4WP can fix it however they want, but if they are dragging their feet, they should just pay Toyota for new sensors if that’s what Toyota says.

 

$3,500 for both sensors installed. Product is marketed as BSM compliant. 4WP has been reasonable so far. I’m concerned the $3,600 price could present a problem. Since 4WP is a national chain I hope they do the right thing. I’m still having trouble understanding how not disconnecting battery could kill the sensor outright . Bottom line this headache started immediately same day of install. I have dropped 15k in upgrades at 4WP

 

O man. That sucks. Hopefully 4wp comes through for you. They have been good with tires I’ve purchased and had issues with. Main reason I come back.