Brakes: 850: Should my car have ABS?

[JohnM 855 T5R]

Hi again,

From what you describe, it seems as if the ABS isn't working. Below are all the fault codes that can be generated and from the diagnostic test document I have, it appears that all of them should (in theory!) cause the ABS light to stay illuminated. You'll see that these cover just about any eventuality. Thus I am a bit stumped. Can you read the ABS codes?
1-1-1 No Faults Detected
1-2-1 Left Front Wheel Sensor, Circuit Fault At Speeds Less Than 25 MPH
1-2-2 Right Front Wheel Sensor, Circuit Fault At Speeds Less Than 25 MPH
1-2-3 Left Rear Wheel Sensor, Circuit Fault At Speeds Less Than 25 MPH
1-2-4 Right Rear Wheel Sensor, Circuit Fault At Speeds Less Than 25 MPH
1-4-1 Faulty Pedal Sensor, Short To Ground Or Voltage
1-4-2 Faulty Brake Light Switch, Open Or Short Circuit
1-4-3 Control Module Fault
1-4-4 Brake Discs Overheated
2-1-1 Left Front Wheel Sensor, Signal Absent When Moving Off
2-1-2 Right Front Wheel Sensor, Signal Absent When Moving Off
2-1-3 Left Rear Wheel Sensor, Signal Absent When Moving Off
2-1-4 Right Rear Wheel Sensor, Signal Absent When Moving Off
2-2-1 Left Front Wheel Sensor, Signal Absent In ABS Function
2-2-2 Right Front Wheel Sensor, Signal Absent In ABS Function
2-2-3 Left Rear Wheel Sensor, Signal Absent In ABS Function
2-2-4 Right Rear Wheel Sensor, Signal Absent In ABS Function
3-1-1 Left Front Wheel Sensor, Open Or Short Circuit
3-1-2 Right Front Wheel Sensor, Open Or Short Circuit
3-1-3 Left Rear Wheel Sensor, Open Or Short Circuit
3-1-4 Right Rear Wheel Sensor, Open Or Short Circuit
3-2-1 Left Front Wheel Sensor, Intermittent Disturbance At Speeds Greater Than 25 MPH
3-2-2 Right Front Wheel Sensor, Intermittent Disturbance At Speeds Greater Than 25 MPH
3-2-3 Left Rear Wheel Sensor, Intermittent Disturbance At Speeds Greater Than 25 MPH
3-2-4 Right Rear Wheel Sensor, Intermittent Disturbance At Speeds Greater Than 25 MPH
4-1-1 Left Front Wheel Inlet Valve, Open Or Short Circuit
4-1-2 Left Front Wheel Return Valve, Open Or Short Circuit
4-1-3 Right Front Wheel Inlet Valve, Open Or Short Circuit
4-1-4 Right Front Wheel Return Valve, Open Or Short Circuit
4-2-1 Rear Wheel Circuit Inlet Valve, Open Or Short Circuit
4-2-2 Rear Wheel Circuit Return Valve, Open Or Short Circuit
4-2-3 TRACS Valve, Open Or Short Circuit
4-2-4 TRACS Pressure Switch, Faulty Or Short Circuit
4-4-1 Control Module Fault
4-4-2 Pump Pressure Too Low
4-4-3 Pump Motor, Electrical Or Mechanical Fault
4-4-4 No Supply To Hydraulic Unit Valves

Originally Posted by ITSv40

Why not find a stretch of quiet, straight flat road and do an emergency brake test. It should be fairly obvious if the ABS is working or not and kinder on your sphincter.

That's good advice.
Regards
John

[RaelG]

I may well try and find a quiet stretch of road one time, and like you say give it a couple of safe tests.

Unfortunately for some reason I cannot pull any codes from my car. I built a little code reader and it doesn't read the codes. I also can't kill the "i need a service light". I suspect, from the tiny amount of research I did, that the ECU has stopped accepting signals. No idea why!

Will report back once I've done some testing, but welcome any more checks I can do in the meantime.

[PNuT]

I had abs issues once, someone had changed the abs pump & mixed the lines up so when it wanted to stop the fronts locking up it released pressure from the rear.... & vice versa....

Wasn't much fun to be honest!

[Bob Meadows]

If the car is anything like a '97 V70 then the service light needs a dedicated tool or Volvo FCR (forum member done mine - think its called FCR?)

I also tried a couple of code readers without success:~
It may just be the above and not the ECU that are generally reliable.
Bob.

[RaelG]

The brakes in general feel perfectly normal, in fact they feel very good perhaps due to them being some sort of upgrade from standard.

It’s apparently a random year (or maybe one of two) where it has an OBD2 port but it isn’t OBD2 compliant so it won’t work with traditional readers. At least that’s my understanding. So my local garage couldn’t read faults or clear the service light with any of their tools and my home made jobbie won’t read them either. It’s stumped me so I just have to ignore the service light now which is tedious but hardly the end of the world.

[4x4]

The service light needs reset every 12 months (unless the settings have been changed from factory settings)

Once reset the light does a 'system check' when the ignition is turned on then extinguishes immediately once the engine starts.

When the 12 month service period expires the light stays on for a couple of minutes before extinguishing and this happens every time the engine is started

Plenty posts on the forum of owners removing the bulb...

You need a special tool to reset the service light. I have one for sale if you're interested

[RaelG]

Yeah so mine is doing the "stay on a couple of minutes" thing. Like I said it isn't the end of the world, just one of those slightly irritating things. Like 1 fly while you're trying to drink a beer...slightly irritating, but nothing compared to a bunch of wasps...I think you get the idea.

As for the special tool...given my lack of success in reading codes either with a code reader or a home made one, I wouldn't bet on the success of anything else so I shall politely pass on that.

[Luxobarge]

Originally Posted by RaelG

As for the special tool...given my lack of success in reading codes either with a code reader or a home made one, I wouldn't bet on the success of anything else so I shall politely pass on that.

Hi Rael - I have the draper service light reset tool, it works on my V70, I don't know for sure whether it will work on yours but you're welcome to pop round and have a try one day if you like - you know where I am! Much better to reset it than take the bulb out IMHO.... Cheers!

[RaelG]

Originally Posted by Luxobarge

Hi Rael - I have the draper service light reset tool, it works on my V70, I don't know for sure whether it will work on yours but you're welcome to pop round and have a try one day if you like - you know where I am! Much better to reset it than take the bulb out IMHO.... Cheers!

Very kind offer sir, I may well take you up on that and pop over. I won't take the bulb out, so will either live with it or find a solution. I shall be in touch

[Clan]

Originally Posted by ITSv40

Why not find a stretch of quiet, straight flat road and do an emergency brake test. It should be fairly obvious if the ABS is working or not and kinder on your sphincter.

on a wet day preferably