ASR light

[SL500_WPB]

Interesting, haven't heard of that one before but makes sense.

 

[French02chris]

Interesting, haven't heard of that one before but makes sense.

if the line is leaking , it can't hold pressure....if it can't hold pressure, it can't charge the ASR pump...so my ASR light would come on

 

[gerryvz]

I drove my E500 on Sunday after (and I am ashamed to admit this) not driving it since I think October or November 2022. Of course, the ASR light went on after the ASR pump cycled itself for the two or three minute period (I could hear/feel it humming while it was cycling).

I have not yet replaced the brake fluid (it has been some years since I last changed it) and I believe that old brake fluid is clogging the pre-charge pump.

In any case, when this happens, I am often able to clear the issue (the stuck pre-charge pump) by flooring the accelerator during the first couple of minutes while the ASR pump is cycling, before shuts off and activates the ASR light in the cluster.

By doing this, ASR is activated (the triangle in the center of the speedo lights up) and this forces fluid to circulate through the system and into the pre-charge pump and ASR pump. And then (particularly the next time you start the car, resetting the full cycle) it acts normally.

It's a Band-Aid fix for the problem, until a) new fresh clean fluid is replaced in the system, which should help "unstick" the ASR pump and allow a proper charging cycle; and/or b) the pre-charge pump is removed and cleaned (which is a difficult job due to its location under the master cylinder and booster area).

So, I'm going to change fluid and see if that solves the problem of properly lubricating the system. If not, then I will have to remove and rebuild the pre-charge pump. I have the parts and new tubing for it in hand.

To reiterate, if you have this issue, and want to try to resolve it, try forcing the ASR system to activate BEFORE the ASR pump stops cycling and lights up the ASR lamp. But only floor it with a warmed-up car.

 

[SL500_WPB]

I drove my E500 on Sunday after (and I am ashamed to admit this) not driving it since I think October or November 2022. Of course, the ASR light went on after the ASR pump cycled itself for the two or three minute period (I could hear/feel it humming while it was cycling).

I have not yet replaced the brake fluid (it has been some years since I last changed it) and I believe that old brake fluid is clogging the pre-charge pump.

In any case, when this happens, I am often able to clear the issue (the stuck pre-charge pump) by flooring the accelerator during the first couple of minutes while the ASR pump is cycling, before shuts off and activates the ASR light in the cluster.

By doing this, ASR is activated (the triangle in the center of the speedo lights up) and this forces fluid to circulate through the system and into the pre-charge pump and ASR pump. And then (particularly the next time you start the car, resetting the full cycle) it acts normally.

Its a Band-Aid fix for the problem, until a) new fresh clean fluid is replaced in the system, which should help unstick the ASR pump and allow a proper charging cycle; and/or b) the pre-charge pump is removed and cleaned (which is a difficult job due to its location under the master cylinder and booster area).

So, Im going to change fluid and see if that solves the problem of properly lubricating the system. If not, then I will have to remove and rebuild the pre-charge pump. I have the parts and new tubing for it in hand.

To reiterate, if you have this issue, and want to try to resolve it, try forcing the ASR system to activate BEFORE the ASR pump stops cycling and lights up the ASR lamp. But only floor it with a warmed-up car.

Funnily enough, the last time I drove my SL500 was probably around the same time. It developed a surging/rough idle after engine warm-up and i've been too busy to look into it. Ordered up some new rotors, caps, and insulator shields which should be here later in the week and solve that issue ().

Looking forward to trying out this band-aid afterwards.