HELP..ABS dash light problem

Started by ausx19V6, July 27, 2010, 01:14:20 AM

Previous topic - Next topic

ausx19V6

Hi guys. Maybe this problem has been discussed here before. I have a 1989 164 12v. The Abs warning light has been on (permanantly) as is the pad wear indicator light. I have been to several mechanics and supposed Alfa experts and they do not have the diagnostic equipment to scan this year model (its too old so they say) I live in Newcastle NSW. The Alfa dealership went bust here a few years ago, and the nearest is in Sydney.
The car has been unregistered for a few years and the abs light is the only thing stopping it from getting a blue slip passed.
I am no mechanic but I would like to check a few basic things myself.
Can anyone tell me the location of the ABS fuse?
I have looked at the main fuse box but everything is in Italian, so without the help of a service manual (in english) its all foreign to me.
Thanks in advance for any help that can be offered.

Typhoon90

#1
I know very little about your car, but you will need a workshop manual, or at least the ABS system diagnostics section.
I went through this with my 1990 Volvo wagon, when I bought it, the ABS warning light had been removed from the dash, only found out about it when the rear locked up one day....
But I digress. On some vehicles around this age, the ABS system is linked into the self diagnostics system of the vehicle, meaning you can pull codes out of the system. You will need the manual for this.
On other cars, it's much harder. On my Volvo, I had to run through a long battery of tests, starting with measuring resistances and voltages at the ABS computer main harness connection, through to bridging certain wires to ground or +12v, to activate certain parts of the system. In the end it turned out to be a bad relay on the ABS pump.
The big bonus with ABS systems is that they are a very specialised system, so only one or two companies manufacture the systems and car manufacturers buy the system they want and have it calibrated to a particular model line, which means once you know a particular system you know most cars of that era. It also means parts are usually cheap to source too, if you buy from less "prestige" parts houses.
The really good news is that ABS systems are built to a standard, not  a price, so USUALLY, the very large, expensive stuff like the actual ABS computer and pump don't fail. Most of the time it's a sensor or a voltage /ground problem.
So, get the manual and see how you go. No offence to anyone, but when I was trying to diagnose the issue on the Volvo, all I got was the old internet folklore " oh, it's the xyz, they always fail". And of course, it never was the xyz and when you read the workshop manual, xyz is never the primary cause in the first place!
What I found interesting is that about 85% of the potential problems listed in the Volvo ABS system are ground/power issues.
Just found this, it may help:
http://www.alfabb.com/bb/forums/164-168-1991-1995/160782-1995-164ls-ecm-abs-srs-diagnostic-connectors.html
Regards, Andrew.

VeeSix

One of the wheel sensors has probably just gone bad or there is a fault with the ABS unit, both can be replaced relativly easily, when any part of the ABS system goes bad the system just goes back to regular brakes so the vehicle will brake just as good just without ABS assistance, a ABS light on the dash will not stop a blue slip, and even if it did you can remove the bulb in five minutes and no-one would know, i too am in Newcastle and am constantly stripping 164s so if you need any parts just send me a e-mail, i have 95% of 164 parts constantly in stock.
Thankyou VeeSix.
1985 Alfa Romeo GTV6 V6 2.5 12V 
1986 Alfa Romeo 90 V6 2.5 12V
1990 Alfa Romeo 75 V6 3.0 12V Potenziata
1990 Alfa Romeo 164 V6 3.0 12V Zender
1991 Alfa Romeo 164 V6 3.0 12V QV
1992 Alfa Romeo 164 V6 3.0 12V QV

ausx19V6

thanks for your input with this problem. yes, they did knock it back for a blue slip because the light must illuminate and then go off. I pulled the globe and went back, but the guy told me that was not acceptable. if it has Abs it must function. The car is now at Newcastle motor repairs at merewether and the latest is a faulty ABS ECU. I have told them that I do not want to spend a fortune, I just want the light to go on, and then go out after start up. I suggested putting a timer in the circuit to fool the blue slip guy. Waiting to hear back.
Cheers.
Veesix, can you give me your email or maybe a phone number so I can get some parts if I need them?

Colin Byrne

Careful with this stuff guys, the ABS hydraulic unit doesn't just function during en emergency stop, most of the time the unit is also responsible for controlling the brake pressure to the rear axle during a threshold stop.
If it is not functioning correctly this brake biasing function may not be provided and result in rear wheel lock up during a stop, when the rear wheels lock they can no longer provide lateral grip and this will destabilise the vehicle, possible causing it to spin etc.
I worked as an ABS calibration engineer for a few years (I now calibrate stability control) and I would recommend ensuring the system is functioning as intended
72' 105 2000 GTV Red (tarmac rally/race car)
74' 105 2000 GTV Blue (road car)
68' 105 1600 Giulia Super White (Not sure yet)
01' Nissan Pathfinder (Tow car/Alfa support vehicle)

ausx19V6

thanks for that. I am currently trying to chase down a secondhand ABS ECU. From enquiries I have made they want more for that part than what I paid for the car.
Hopefully David Tracey will see this and call me (chris 0458154149) I think he may have one.

Typhoon90

#6
Diagnose the system, throwing parts at it is wasting money. You should make the effort to obtain the diagnostic material to do so, it will save you a fortune.
An ABS light will most definitely cause a fail on any legitimate blue (or pink) slip inspection.....

Regards, Andrew.

ausx19V6

it is currently being diagnosed by a qualified auto elect. the problem being that there are no current diagnostic equipment that will connect to this vehicle due to its age. They have manually tracked the fault to what they say is the source...the ABS ECU, so I have to take there word that replacing it will solve the problem.

Typhoon90

I can all but guarantee you don't need diagnostic equipment to pull codes out of a vehicle of this age. Most all of them carry on board diagnostics. Even an auto electrician is just guessing if they aren't running the diagnostics tests.

Regards, Andrew.

stustustu123

Have you spent much time cleaning up the connections to the ABS unit in the engine bay?  I believe there is a large multi-pin connector on top that often (due to age of plastics / rubber seals) isn't completely impenetrable by moisture/dust etc.  I remember reading reports on the old Alfa 164 digest (http://www.digest.net/alfa/FAQ/164/) from people in countries where the roads used to get salted during winter that issues would arise here due to water ingress causing corrosion of the connector terminals.

I guess I'd start by cleaning any and every ABS related connector I could find with some electrical contact cleaner.
2007 159 SW 2.4 JTDM
1993 164 Super
Past:
1994 164 Super (Blue)
1992 164Q (Black)
1989 164 (White)
1988 75 3.0 V6
1983 Sud Ti