Can the power steering be switchable on a C6?

[Marc p]

Okay, I'll give you a quick bit of background, driving my C6 to work the other day, I get a tire pressure warning light on, appears to be a slow puncture so thought I'd just top it up after work as it wasn't that low (24psi ish), next thing I know, I get the 'service active handling' warning up, not a problem, had this a year earlier due to a low tire pressure, didn't cause any issues that time so just ignored it.

Then something happened that I wasn't expecting, I came off a roundabout at about 20mph and the car just anchored on a brought the car to complete stop, leading to the car behind being mm's away from smashing into the back of me, I then went to pull off, got to about 15mph and again, brakes lock up, can't accelerate and brings car to a complete halt, I then pulled the car up to the side of the road and the DIC went mental, cant remember how many things it disabled but it spent some time cycling through everything that it had disabled.

So I pull off again and the car appears fine, I'm being cautious but appears the car can accelerate as normal so I decide to drive it to the services to get some air in the tires. It was at this point I noticed that the power steering appeared to have been disabled as well as the steering had become VERY heavy.

We now reach my point, when the power steering wasn't active, the car felt nothing short of incredible!! Not only was the responsiveness seriously heightened, I had so much feeling through the wheel, not a smidge of vagueness, to the point where I got to the petrol station topped it up with air, all errors went away, power steering came back and it just felt.............naff, I always commended the cars handling but now I know how good it can be, it's not quite so great.

So seeing as the car literally disabled power steering itself, surely there must be a way to have it switchable as I wouldn't want to remove it completely as it's a bit too heavy when maneuvering.




TL;DR - Lost PS, loved it, PS came back, want to lose it again without being permanent.

Edited by Marc p on Wednesday 26th September 19:51

[GW65]

That is seriously weird... The C6 has hydraulic power steering, and as far as I know there's no way it can be disabled.

Given all the errors you were getting, my first thought was a dodgy battery...so I wonder if it's a drive-belt issue that affected the alternator and power-steering? I did get some weird noises that went away when I replaced my dying battery, which sounded like drive-belt or pump-related noises....

[300bhp/ton]

I don't know specifics on the C6, but if it's a hydraulic pump and not electrically driven or electric assist, then there is likely no way it can shut itself off.

Are you sure it really wasn't working? Flat tyres could make it feel heavier. And with no PAS I suspect the steering would be hugely heavy at walking speed or stationary.

[Marc p]

GW65 said:

That is seriously weird... The C6 has hydraulic power steering, and as far as I know there's no way it can be disabled.

Given all the errors you were getting, my first thought was a dodgy battery...so I wonder if it's a drive-belt issue that affected the alternator and power-steering? I did get some weird noises that went away when I replaced my dying battery, which sounded like drive-belt or pump-related noises....

Now I am confused :blink: I assumed it must of had electronic assistance. Not likely to have been a belt as all the belts were replaced in May, along with a new battery.

300bhp/ton said:

I don't know specifics on the C6, but if it's a hydraulic pump and not electrically driven or electric assist, then there is likely no way it can shut itself off.

Are you sure it really wasn't working? Flat tyres could make it feel heavier. And with no PAS I suspect the steering would be hugely heavy at walking speed or stationary.

Tire wasn't anywhere near flat, besides, it was a rear one anyway, so nothing to do with that. I don't know if if was completely not working but it was seriously heavy and having driven driven cars with no power steering (albeit lighter), it did feel very much that it wasn't assisting at all. even at 30-40mph the wheel was very heavy on the turn in but incredible in feedback. If you've driven a car with no PAS before you'll know what i mean.



Anyhow, I am now majorly confused as to what happened, looks like I'll be delving into a lengthy google search this evening!

[300bhp/ton]

Might be worth heading over to the LS1Tech or Corvette forum, see if it's happened to anyone else.

[BlackZeD]

The steering is speed sensitive, i. e. gets heavier at speed and lighter round town.
I am assuming there will be a few sensors to run that.
I would check the fliud in the pump first, if its low going round a corner might have affected it somehow.

[Marc p]

BlackZeD said:

The steering is speed sensitive, i. e. gets heavier at speed and lighter round town.
I am assuming there will be a few sensors to run that.
I would check the fliud in the pump first, if its low going round a corner might have affected it somehow.

Did some research last night and you are correct, the steering is electronically assisted through the use of magnets that slowly decrease assistance as you get faster.

When it was disabling all the aids due to the active handling issue, it also disabled the cars VAS (Variable Assisted Steering) and dropped all assistance to the power steering.

Now I just need to find a way to override it to turn it off or decrease it's assistance, looks like I need to get into the ECU and have a play around.

Simplistic diagram of how it works:

[300bhp/ton]

Is there a fuse for it? Either that or see if you can find the wires for it and maybe look at adding a switch in-line to turn it on/off. Not sure if the ECU would have a hissy fit though.

[BlackZeD]

Looking at that if the variable speed signal was made to stay as if you were running at a high speed, voltage input from a seperate potentiometer it would keep the assistance low.
That might have parameters that could be changed in the ECU as well, possibly in a table.