ABS control-lamp is on and breaks lock at hard pedal.

 

What?

Year/Make/Model?

 

You going to have to give a little more info, year, model I am assuming that the problem is the brakes are not pulsating when ABS is supposed to kick in. The light indicates a fault in the ABS system. This could be a wheel sensor, ABS module. Depending on year you can use the self-dianostic system on your car can tell you all kinds of good info. But we don't know what year you have.

 

What he said.

 

Thanks jbuck.
1992, 850 GLT.
This is exactly what happens. I've checked faut codes and found it to be:
312, 313, 314, 323, 324, 211. As it happens they all relate to faulty sensors.

 

Try cleaning the sensors with brake cleaner first. They get really dirty and cleaning sometimes will work.

 

How long has it been on? Is it a condition you bought it with? It might be a good idea to get the light reset and see what comes back.

2nd Jbuck.
Wouldn't hurt to clean the sensors and the ring on the CV joint of foreign material and blow them dry in case that's the cause of the faults.

 

1. Kiss4aFrog, it started for some months ago now, but did not influence break function until now. How do I reset the light?
2. I got the same tips from my friend (thank You kindly Jbuck). He said it would not hurt to replace BreakLight/ABS-switch behind break-pedal (@$32), what do You think? Anyway, I start with cleaning sensors.....

 

You may have a diagnostic panel under the hood located next to the washer fluid fill tube.

How did you read the codes??

Here are instructions on how it works. Should be able to reset.


http://www.matthewsvolvosite.com/how...-obd-unit.html

 

The switch behind the pedal is just a brake light switch.

 

Is it an 850 series? Are you sure it's a 1992

The brake light switch is simply a spring loaded on off switch with only two contacts. You have a hot wire coming in that will be hot all the time no matter what the key position and the other lead off the switch should be dead when the pedal is in the up position and should turn "on" when the pedal is depressed. There should be a little bit of play where the switch doesn't come on immediately.

It's easy enough to test with a voltmeter or 12 volt test light. That and if your brake lights come on, it's good

BUT on my 95 850 that isn't what sends a signal to the cruise control. I don't have info on an earlier model year but on my brake pedal there should also be a vacuum valve that would look similar to the brake light switch. That is the control for turning the system off when you step on the pedal and would need to be checked to see if that's what is keeping your system from engaging.

Below is the electric stop light switch

 

I used swedish site for my model 850 '92:
file:///C:/Documents%20and%20Settings/Marian%20Blacharski/Skrivbord/Felkoder%20till%20850%20%E2%80%A2%20Sveriges%20Vol voforum.htm
Inserted test-wire into A3, turned ignition on and read codes after pressing test-button.
I am not ready with cleaning sensors, I hope tomorrow will be the time for it.
Thank You all for help.