2015 canyon 4-Lo manual mode issues

RichG said:

4-Lo when in manual mode to use engine braking downhill off road holds my truck at a nice and slow speed if I don’t touch the gas. however as soon as I just barely touch the gas (and then quickly take foot off) the revs start climbing and the engine braking doesn’t seem to keep the truck descending at a controlled rate. I then have to rely heavily on the brakes.

has anyone else experienced this? Thoughts on what could be happening? It doesn’t seem normal to me.

2015 Canyon CCLB 3.6v6

Thanks!

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impact said:

I know it is a lot to digest but were all these conditions met with your descent?

From the owners manual:

Hill Descent
Control (HDC)

If equipped, HDC can be used when
driving downhill. It sets and
maintains vehicle speed while
descending a very steep incline in a
forward or reverse gear
.
The HDC switch is on the center
stack, below the climate controls.
Press switch to enable or disable HDC.
Vehicle speed must be below
60 km/h (37 mph).

The HDC light displays on the
instrument cluster when enabled.

HDC can maintain vehicle speeds
between 4 and 30 km/h (3 and
19 mph) on an incline greater than
or equal to a 10% grade. A blinking
HDC light indicates that the system
is actively applying the brakes to
maintain vehicle speed.

When HDC is set, that is the initial
set speed. It can be increased or
decreased by applying the
accelerator or brake pedal. Smaller
HDC speed control adjustments are
accomplished using the cruise up or
down buttons. Each tap of the
+RES will increase the set speed by
0.8 km/h (0.5 mph), while each tap
of the SET– will decrease the set
speed by 0.8 km/h (0.5 mph). This
adjusted speed becomes the new
set speed.

HDC will remain enabled between
30 and 60 km/h (19 and 37 mph),
however vehicle speed cannot be
set or maintained in this range.

It will automatically disable if the
vehicle speed is above 80 km/h
(50 mph) or above 60 km/h
(37 mph) for at least 30 seconds.
Switch must be pressed again to
re-enable HDC.

When enabled, if the vehicle is at a
speed above 30 km/h (19 mph) and
less than 60 km/h (37 mph), a DIC
message will display instructing the
driver to reduce speed for HDC
operation.

Cruise control will not function while
HDC is enabled and vehicle speed
is below 40 km/h (25 mph).

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F8LZ71 said:

I assume you have 1st gear selected as the highest gear? If not then in the conditions you describe it will upshift to whatever the highest gear you have selected and you'll lose compression braking.

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RichG said:

The result is the same regardless of gear in manual mode.
For example, if I start off in 1 but decide the crawl is too much of a crawl, I'll upshift to 2. It stays at a crawl, slightly better but maybe still a little slow, so I ever so slightly touch the gas and then it's like something disengages and the revs climb and the vehicle picks up speed.
I have selected (manually) the gear (2 for example) I want but the addition of a quick touch of the brake pedal makes the engine braking fail and the need to apply the brakes.
Surely if I just touched the gas, the revs would go up a bit and the vehicle would speed up a bit for sure, but if I released the gas pedal the vehicle should come back to it's rate of speed with engine braking at that specific grade no?

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RichG said:

Yeah I understand it won’t drop back to 1st gear, but it’s more the fact that the selected gear doesn’t appear to hold a consistent speed once the gas pedal is literally touched once. It’s like it tells the engine/transmission something and then it decides to let the revs climb rather than keep holding the truck at a consistent speed using the engine.
perhaps I have too much hope the for the ability of the engine braking system. For example the other day I was in 4-Lo in 2nd gear going about 8-10km/h, being held at that speed.. but the conditions allowed a faster rate of descent so rather than change gear I thought I would up the speed ever so slightly using the gas as the grade steepened again a little further down the trail so 3rd gear seemed unnessecary. As soon as I dI’d that, the holding ability disappears and the truck starts gaining speed and revs climb to upwards of 4000rpm+ in 2Nd gear in 4-Lo. It’s something to do with the addition of a throttle response, but it doesn’t seem right.

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