Red AYC + flashing/flickering green bars!

[mattd]

Hi guys,

Got a problem with a 1996 VR4, the red AYC light is constantly on (new switch thinks I) but also the green bars randomly and rapidly flicker/flash/blink on off whilst driving normally (e.g. in a straight line)

The TCL OFF is also on, as is the engine check light - But I suspect this is the old vacuum pipes problem.

Anyone able to shed any light on this? I'd like to try a new switch, but was suggested to ask here first!

Thanks!

[bradc]

Most likely the tyres are different types, or they've worn unevenly, or have different pressures.

[Nick Mann]

It's a wierd one.

Off the top of my head:
The red AYC light normally stops the AYC working, so no green bars.
Flickering green bars in a straight line means the AYC ECU thinks one wheel is not moving the way it should. This is either a wheel/tyre problem, as Brad says, or a speed sensor problem, or an ECU problem.

First and easiest thing to do is follow Brads advice. Check your tyre condition, size and pressure. Make sure they are all good!
If the red AYC light is lit at the same time as the green bars are flickering, I would suggest trying a different AYC ECU. Do you live near anyone who would be willing to swap for a couple of days?
If the flickering green causes the red AYC light to come on and then the flickering bars cease, I would start with the speed sensors and abs rings.

The Switch problem (dodgy switch/low pressure from a worn pump) tends to give a red AYC light, then no green bars at all. It does not cause flickering bars whilst driving in a straight line. I would put that at the back of the list for now.

Let us know how far you get!

[Davezj]

lots of good advice.

[mattd]

Indeed, thanks chaps, I will look into it and get back to you.

It's not my car though, it's a bit of a long story but we'll try and get it sorted!