Is there any fault rentention memory that shows the same fault for a potential symtom despite many restarts/driving?

I'm particularly interested in the ABS.

After a relay replace, fluid flush and front brake pad replacement the light was still on.

Disconnect the batt and no light on reconnect/car start and brake pedal 'feels' more solid.

 

Malcolm,

Faults on diagnostically enabled systems are stored in the individual modules. I know the LH and (latest) alarm system store fault memory items - I would not be surprised that the ABS does too - but I don't know for sure. I'm sure John Speake knows the answer to this though...

However on an '88 you do not have the latest of the ABS systems (the one that combined ABS & PSD) - this later system was diagnostically enabled but the <'89 version was not.

Alan

 

Malcolm, I hate to be the bearer of bad news but...it's terminal. Please accept my deepest sympathies.

The best thing is to move forward. Just so happens I'm in the market for a companion for my "88. I'll do you a favour...

Seriously, I have no specific answer for you but will ask; have you checked or replace your grounds?

 

Thanks Alan.

I neglected to mention that while doing the front brake pad R&R I also removed the rotors and cleaned the sensors which were encrusted with filings.

Given that the ABS warning light is now off and the pedal does feel firmer I'll assume that cleaning the sensors, replacing the relay and the batt disconnect has the system working.

I'll give it a good try tomorrow or I'll be smoking those front PS2's ........again.

 

Funny guy Mike..............you got a great car there despite the issue.

If you need any assistance let me know..............there's a few of us around in the area.

 

Malcolm - stand as hard as you can on the brakes..continuously - preferrably somewhere loose (gravel/wet etc) see how the pedal feels and the car responds...

ABS alone should not have changed how the brakes feel - untill it goes active it has no effect on braking (so it was probably the new pads etc). Even when operating ABS modulates the brakes to less pressure in momentary bursts... that's what you are feeling for - pulsing when active...

Alan

 

Thanks Malcolm...much appreciated! I picked up the 28K replacement engine yesterday. To my relief and surprise I would guess it probably has 28K on it. Looks good enough to plop in the old beast...but of course I'm not that smart

Sorry, not meaning to hijack...back to the top>

 

Hello Malcom,
Alan is correct that the early ABS does not support diagnostics, only the later PSD/ABS ECU.

I seem to remember there was some obscure test set that could be used for some kind diagnosis for th early systems, it may be described in the W/S manuals.

 

The most common problem is a wheel speed (hub) sensor faulty. Doisconnect them all near the hub, use a multimeter to check if any then show a short to chassis. If so, this will indicate that the sensor has been crushed by corrosion in the hub, and needs replacement.

You can also use your multimeter on a.c. volts to do a rough test of each output voltage by spinning wheel and checking if the 4 output voltages are similar from each wheel's sensor.

 

Thanks John............its interseting that disconnecting the batt. did reset the warning light though.
If it returns (hope not) I'll run through the tests you mention.

Alan.........I agree the ABS should not affect the hydraulic side of the brakes; the new pads are ceramic. I'll try the gravel test.........the driveway is 1/2km long.

 

Back to the drawing board. Light came back on this aft after 50kms of driving.

The ABS is definately not working as Alans test confirmed lockup. The wheels are more off than on these days.