Whoa! WTF? Safety Hazard on Cascadia Cruise Control

[PapaDough]

Cascadia smart wheel pod:

Is it possible the O/P bumped the cruise switch by accident? The "set" button is exactly opposite the "engine brake" button.

Ergonomically very uncomfortable to hold, gives hand strain and the buttons are easy to hit accidentally and within a few weeks they fade to black and you have no idea what button is for what without hitting them at random to see what happens.

This thing with all controls on the steering wheel, radio tuner, phone, sat radio, fan control et cetera is exasperating and very annoying.

 

[PapaDough]

On the recent, 2016 and 2017, Cascadias with the automatic transmission, the jake is on the shifter, which is like a turn signal post but on the right side (where the johnson bar used to be on some trucks). The post has 4 positions, all the way up the jakes are off, all the way down is full jakes......

..... If you then move the jake control back to the off position, the cruise will come back at the preset speed, unless you touched the brake pedal at some time to effectively cancel the cruise.

Yes. That is what I drove the other day.

All the trucks I've driven, the cruise never re-engages if you activate the jake brake. The jake on the Cascadia merely suspends the cruise until the jake is turned off, at which time the truck starts to accelerate back to set speed. This should NOT be.

 

[ironpony]

Yes. That is what I drove the other day.

All the trucks I've driven, the cruise never re-engages if you activate the jake brake. The jake on the Cascadia merely suspends the cruise until the jake is turned off, at which time the truck starts to accelerate back to set speed. This should NOT be.

It gives you an option in how to use the jake brake. If it gives you heart burn, just turn the cruise control off, otherwise, I find the way its set up to be just fine.

 

[Tazz]

On the recent, 2016 and 2017, Cascadias with the automatic transmission, the jake is on the shifter, which is like a turn signal post but on the right side (where the johnson bar used to be on some trucks). The post has 4 positions, all the way up the jakes are off, all the way down is full jakes. On the very end of the post is a push button that you use to switch from auto to manual (a paddle type shifter, the post also moves towards you to upshift and away from you to downshift). Just to the inside of that is a 3 position twist knob that is either forward, reverse, and neutral in the middle. Whenever the cruise is on and engaged, the jake brake is on a setting that will only slow the truck if you go a certain amount over your set speed. If you move the jake control to any of the 3 on positions, the cruise goes to standby, you can use the foot throttle to speed up if you need to. If you then move the jake control back to the off position, the cruise will come back at the preset speed, unless you touched the brake pedal at some time to effectively cancel the cruise.

I'll have to try that. I have always turned off the cc or hit the brakes when I decide to slow down.

 

[PapaDough]

I'll have to try that. I have always turned off the cc or hit the brakes when I decide to slow down.

Generally on a sparsely travelled highway at night, I use the jake brake to slow the truck, take my exit, and then hit the brakes coming up to the stop light. Saves a bit of wear and tear on the brake pads and exercises the engine retarder at the same time.

 

[Fredl]

But now you know it
Think its on all Mercedes i know.

Hello Mr. Giroux (Media Relations, Daimler Trucks North America)

I have recently driven the new Cascadia here in Canada and I am compelled to write you regarding my experience. Overall, it is a comfortable, well-made truck but there is a dire safety hazard that needs immediate attention.

When the cruise control is engaged and the engine brake is activated, the truck slows down very well, but surprisingly, the cruise control does not disengage automatically when the engine brake is shut off. Alarmingly this happened on an off ramp from highway speed to a local road intersection. After the engine brake decelerated the tractor-trailer from 60 mph to 40 mph, I was dumbfounded to discover the truck accelerating back up the exit ramp, with the engine brake shut off. I had to immediately hit the service brake hard, stomping it to make the vehicle halt at the stop light. All ended well but I was still trying to figure out what had just happened.

Of all the trucks I have driven to date, and I have been driving for more than 13 years, this is the first time I have come across a cruise control that does not automatically and permanently deactivate when the engine brake is engaged. In my experience to date, including Freightliner Trucks, the cruise control must be manually re-engaged after the engine brake has been activated.

If this is a software glitch, or otherwise not the proper behaviour expected with this Cascadia and this is definitely a malfunction then you may want to contact me for further information on the truck and its location where it is in service. I believe this is a serious issue that merits further discussion. If I am incorrectly handling the electronic settings on this truck, please advise. I would be happy to upgrade my education.

Please share this email with those who can provide constructive feedback. I look forward to your reply.

Thank you.

Sincerely,

PapaDough

 

[Fredl]

Cascadia smart wheel pod:

Is it possible the O/P bumped the cruise switch by accident? The "set" button is exactly opposite the "engine brake" button.

Steering Wheels Big Rig Chrome Shop - Semi Truck Chrome Shop, Truck Lighting and Chrome Accessories

 

[Tazz]

Generally on a sparsely travelled highway at night, I use the jake brake to slow the truck, take my exit, and then hit the brakes coming up to the stop light. Saves a bit of wear and tear on the brake pads and exercises the engine retarder at the same time.

To each their own. Brakes are made to wear in my opinion. Although newer brakes seem very durable. Last Freightliner I ran to 500k only used two sets of front disc pads, and one set of drums on the drives.

By using the engine brake that wear is transferring to one set or maybe two sets of drive tires depending on truck specs. As well as pressure on the driveline in general. That energy is being dissipated somewhere.

I generally only use an engine brake in maintaining speed on downgrades where heat build up is a concern.

RIght now we only get 10 speeds unless a 3MM spec truck. So I know ours will not engage with cruise engaged. If I see an auto around I try it out.

 

[ironpony]

Leaving the cruise engaged on a less steep downgrade, and engaging the jake will result in a little less jake effectiveness. Turning off the cruise control will bring the jake up to full effectiveness. I've never seen a prohibition against using it in this manner. That's on a 2009 with a 10-speed manual. I'm not sure if it works the same way with the new DT12 drivetrain.

 

[Tazz]

Leaving the cruise engaged on a less steep downgrade, and engaging the jake will result in a little less jake effectiveness. Turning off the cruise control will bring the jake up to full effectiveness. I've never seen a prohibition against using it in this manner. That's on a 2009 with a 10-speed manual. I'm not sure if it works the same way with the new DT12 drivetrain.

Only when you get above set speed right? And then the engine brake phases in?

 

[ironpony]

Only when you get above set speed right? And then the engine brake phases in?

Yep. I don't run around with the jake armed like that normally. It will retard the engine RPMs while upshifting enough that it causes the gears to grind.

I can't recall why I'd know that.

 

[Injun]

My jake is usually in standby mode while I'm using cruise control. It's "armed" for when I need to slow down.

I did not understand the problem @PapaDough described because I didn't know he was talking about an automatic transmission.

Thank you, @Inkeper for clarifying that.

 

[Duck]

The automatics I've driven have their jakes set up stupidly.

You can either have the cruise on or the jake.

Put the jake on "auto" and it does nothing until you step on the brake pedal. Even if the cruise is set at 65 and you're doing 80 mph.

Put it on 1, 2 or 3 & the same thing happens except it will also activate as soon as you disable the cruise.

Basically if the cruise is on & set, the jake won't do anything regardless of how much you drift above the setpoint unless you intervene.

It completely defeats the purpose of having an automatic in hilly terrain. On mild hills like I-80 across Iowa on which you rarely need friction brakes if your jake is working properly, it's actually more work keeping your speed under control than simply having a manual trans.

Some companies spec their trucks that way on purpose. No jake at all if the cruise is set.

 

[Uncle Birchy]

The automatics I've driven have their jakes set up stupidly.

You can either have the cruise on or the jake.

Put the jake on "auto" and it does nothing until you step on the brake pedal. Even if the cruise is set at 65 and you're doing 80 mph.

Put it on 1, 2 or 3 & the same thing happens except it will also activate as soon as you disable the cruise.

Basically if the cruise is on & set, the jake won't do anything regardless of how much you drift above the setpoint unless you intervene.

It completely defeats the purpose of having an automatic in hilly terrain. On mild hills like I-80 across Iowa on which you rarely need friction brakes if your jake is working properly, it's actually more work keeping your speed under control than simply having a manual trans.

Some companies spec their trucks that way on purpose. No jake at all if the cruise is set.

Mine starts slowing down if it's over the governor.....

I shut the cruise off when I'm riding the hills

 

[Electric Chicken]

Mine starts slowing down if it's over the governor.....

I shut the cruise off when I'm riding the hills

Mine keeps rolling. And ever since I got it back from the dealer, it hasn't been telling the DriverTech (our version of Qualcomm) how fast I'm going. So it can't hollar at me for being over 75.

You can defeat speed governors by unplugging the speed sensor from the drive line, by the way. It can't slow itself down if it doesn't know how fast it's going. But you won't have a working speedometer, odometer, or cruise control.

Not that I've done this. I'm just saying. [emoji23]

 

[Tazz]

Mine keeps rolling. And ever since I got it back from the dealer, it hasn't been telling the DriverTech (our version of Qualcomm) how fast I'm going. So it can't hollar at me for being over 75.

You can defeat speed governors by unplugging the speed sensor from the drive line, by the way. It can't slow itself down if it doesn't know how fast it's going. But you won't have a working speedometer, odometer, or cruise control.

Not that I've done this. I'm just saying. [emoji23]

On older trucks you could, but newer ones know how fast they are going just by the gear and tach. And I would add any mods like that will be recorded by the trucks computer, seen by maintenance during PM's and most likely lead to a drivers dismissal.

 

[Electric Chicken]

On older trucks you could, but newer ones know how fast they are going just by the gear and tach. And I would add any mods like that will be recorded by the trucks computer, seen by maintenance during PM's and most likely lead to a drivers dismissal.

2013 isn't that old. But I agree on the rest. That's why I haven't done it. I like working. Lol.

 

[Electric Chicken]

BTW I should probably make it clear that I did unplug the speed sensor but I didn't drive the truck. I was actually more curious whether that even was the speed sensor as I suspected. It killed off the odometer and the speedo needle went straight down. So then I plugged it back in before I took off.

Just experimenting a little really.

 

[Electric Chicken]

Now that I think about it, these company trucks are usually rev limited anyway so that would probably still keep you from speeding a whole lot.

 

[Hammer166]

I think the newer trucks can also be programmed to derate if the speed sensor is non-functional.