Reduced Braking Performance Scare

[303ChickenMan]

Go up again and see if happens the second time!

Considering I’ve been up there a dozen times in my Toyotas (that never had this issue FWIW), I will be doing this trail again in the future lol.

 

[Ovrland Bill]

Great point. Especially considering that this scenario consisted of sub freezing temps, snow, and icy puddles.

You would think that brake and engine oil temps would be in the temp screen in the off-road menu. I care way less about my tire temps than I do the critical fluids.

Would the available display of Tire Temperature reflect added heat from the brake system (i. e. increased temperature observed after significant use of brakes)?

 

[Brad@SuperiorCO]

Great point. Especially considering that this scenario consisted of sub freezing temps, snow, and icy puddles.

You would think that brake and engine oil temps would be in the temp screen in the off-road menu. I care way less about my tire temps than I do the critical fluids.

Retract my comment. I was coming down Deer Creek 10 days ago. No snow or ice. I don't think that incline would heat up your brakes, I have been there 3x this year with 5 Grenadiers. No one had an issue. But maybe the ice did it, I have zero experience with ice. But also the sub zero should have mitigated it some. It is worth asking Red Noland to as Ineos, what causes the warning. Heat? Too much slipping? The software engineers aren't the best. Was it even real, or a software glitch. It is dangerous.

 

[Eric]

Great point. Especially considering that this scenario consisted of sub freezing temps, snow, and icy puddles.

You would think that brake and engine oil temps would be in the temp screen in the off-road menu. I care way less about my tire temps than I do the critical fluids.

Oil temperature is displayed in the off road screen on the B57 diesel engine version. Which isn't helpful in the US where you only get the B58.

 

[303ChickenMan]

Retract my comment. I was coming down Deer Creek 10 days ago. No snow or ice. I don't think that incline would heat up your brakes, I have been there 3x this year with 5 Grenadiers. No one had an issue. But maybe the ice did it, I have zero experience with ice. But also the sub zero should have mitigated it some. It is worth asking Red Noland to as Ineos, what causes the warning. Heat? Too much slipping? The software engineers aren't the best. Was it even real, or a software glitch. It is dangerous.

Thank for affirming this. I have 10+ years experience driving these roads and never once felt I was abusing the brakes. I’ve driven this particular road a dozen times in my Toyotas and never had an issue like this. I’m trying not to take offense at the comments “ride a lower gear” . Yes, I know lol.

I really think it was something more to do with the pitch and yaw of the corner I was in. It was the first hairpin switchback after you are back under tree-line, right around 11,200ft. I had to go high in the corner to avoid the ice in the bottom of the trail. I was at a very weird and steep angle hitting the corner like I did, but was necessary to avoid the ice.

It felt almost like the system gulped some air being at that weird pitch. I don’t know if that’s possible or not.

Either way, it’s not confidence inspiring for the type of trail riding I like to do. I’d love to have 110% confidence in my brakes on shelf roads.

I’ll be making a call to Red Nolan in the morning.

 

[rob88]

The downhill assist uses the brakes as well. I never had to use a DA on icy roads, but if the brake system heats up, that could also happen with the DA, as it also uses the brakes. Maybe you need to take other measures, as the DA is not designated to go down icy tracks.

Maybe it would be better to use snow chains and winter tires (if not already done) or tire spikes. Every system has its limit and a steep, icy track may be over the limit of every system.

AWo

You're right. Downhill Assist uses the brakes, so it can cause them to heat up on a long, icy slope. It's not meant for that.

For a steep, icy track, your best bet is proper tires. Snow chains or tire spikes are the real solution for that kind of condition.

 

[303ChickenMan]

You're right. Downhill Assist uses the brakes, so it can cause them to heat up on a long, icy slope. It's not meant for that.

For a steep, icy track, your best bet is proper tires. Snow chains or tire spikes are the real solution for that kind of condition.

FTR, DA was on for 50 feet just to get through the tough corner. I’m 90% sure the brakes did not overheat. I’ll talk with my dealer tomorrow to understand more. I’ll post a follow-up.

I’ve reviewed my descent (video for my wife). I was on the throttle more in first gear than I was on the brake. The 1000 foot descent took me 12 minutes. Slow and steady.

 

[NQ94]

My first thought before the mention of brake overheating was a situation the software had difficulty processing. In a good functioning brake system with no internal or external leaks could the right combination of having DA on, feathering the brake, the surface condition, wheel slip, steer angle, pitch and yaw with the brake traction control be enough to find that point the software causes the ABS /traction module to activate in an unexpected way for the situation? A situation where the holes line up and is difficult to replicate.

 

[Clark Kent]

My first thought before the mention of brake overheating was a situation the software had difficulty processing. Could the right combination of having DA on, feathering the brake, the surface condition, wheel slip, steer angle, pitch and yaw with the brake traction control be enough to find that point the software causes the ABS /traction module to activate in an unexpected way for the situation? A situation where the holes line up and is difficult to replicate.

Throw in a slushy wheel speed sensor and it's not hard to see a system condition that the BCM cannot process so it throws the toys out of the pram.
I and others have reported a very specific condition of turning under brakes with increasing body roll that caused the brake pedal to sink. It's not a good feeling.

Edit: BMS BCM

 

[303ChickenMan]

@Brad@SuperiorCO

It’s just little moments like these that make the trail puckery FWIW. It might not be bad if we get some warm days w/o snow.

(Not to derail the convo)



@Clark Kent @NQ94 This seems to be the most plausible. Not confidence inspiring. We’ll see what the dealer has to say.

 

[MileHigh]

@Brad@SuperiorCO

It’s just little moments like these that make the trail puckery FWIW. It might not be bad if we get some warm days w/o snow.


(Not to derail the convo)



@Clark Kent @NQ94 This seems to be the most plausible. Not confidence inspiring. We’ll see what the dealer has to say.

I assume that is ice ahead… did you say what kind of tires you were running?

As for descent control, what is that good for- the sweet spot for its use? We used it in the Red Noland 101 off road class, but is it better low gear and careful braking. Depends on the car, but sometimes I think auto systems like anti-lock braking have issues in low traction scenarios. And if the system is constantly differentially braking, then I could see it building some heat.

 

[303ChickenMan]

I assume that is ice ahead… did you say what kind of tires you were running?

As for descent control, what is that good for- the sweet spot for its use? We used it in the Red Noland 101 off road class, but is it better low gear and careful braking. Depends on the car, but sometimes I think auto systems like anti-lock braking have issues in low traction scenarios. And if the system is constantly differentially braking, then I could see it building some heat.

255/85r17 MT Baja Boss AT2 @ 10PSI.

Low 1-2 was used for the descent in an effort to keep the tires rolling. More throttle was used than braking.

DA was used for 50 feet through the odd corner triggering the malfunction. The thought process was that it MIGHT do a better job at keeping the tires rolling than I where brake application was needed. The corner was relatively low-stakes and an interesting experiment for the system.

John at Red Nolan had not heard of this issue before. He called his engineer who had not heard of this happening either and was unable to explain. They are researching the technicalities of the system today and said they will reach back out to me. John said it sounded to him like a software malfunction considering the unique situation (steep pitch & roll, low traction environment, low range locked, off road mode, and the engagement of DA).

 

[Brad@SuperiorCO]

255/85r17 MT Baja Boss AT2 @ 10PSI.

Low 1-2 was used for the descent in an effort to keep the tires rolling. More throttle was used than braking.

DA was used for 50 feet through the odd corner triggering the malfunction. The thought process was that it MIGHT do a better job at keeping the tires rolling than I where brake application was needed. The corner was relatively low-stakes and an interesting experiment for the system.

John at Red Nolan had not heard of this issue before. He called his engineer who had not heard of this happening either and was unable to explain. They are researching the technicalities of the system today and said they will reach back out to me. John said it sounded to him like a software malfunction considering the unique situation (steep pitch & roll, low traction environment, low range locked, off road mode, and the engagement of DA).

I parked up on that ridge once off the shelf road, probably at 10° pitch 20° roll, or greater. When I started the Gren, I had all types of errors for 15 min, until I could get to a flat spot and restart. It didn't do well. But the brakes were fine. I guess the software engineers IG used just aren't the best.

 

[303ChickenMan]

I parked up on that ridge once off the shelf road, probably at 10° pitch 20° roll, or greater. When I started the Gren, I had all types of errors for 15 min, until I could get to a flat spot and restart. It didn't do well. But the brakes were fine. I guess the software engineers IG used just aren't the best.
View attachment 7912633

Software is the necessary evil in these things. Frustrating.

Awesome pic!

 

[Krabby]

255/85r17 MT Baja Boss AT2 @ 10PSI.

Low 1-2 was used for the descent in an effort to keep the tires rolling. More throttle was used than braking.

DA was used for 50 feet through the odd corner triggering the malfunction. The thought process was that it MIGHT do a better job at keeping the tires rolling than I where brake application was needed. The corner was relatively low-stakes and an interesting experiment for the system.

John at Red Nolan had not heard of this issue before. He called his engineer who had not heard of this happening either and was unable to explain. They are researching the technicalities of the system today and said they will reach back out to me. John said it sounded to him like a software malfunction considering the unique situation (steep pitch & roll, low traction environment, low range locked, off road mode, and the engagement of DA).

Locked? The center diff or rear (and front)?

 

[303ChickenMan]

Locked? The center diff or rear (and front)?

Center only