ABS light

[coolngroovy]

This is strange....why does my ABS light come on when i hit 80k's?

When the ignit is turned off, it goes out. After restarting it is still off.....until i hit 80k's.

Any ideas?

[HoldrodeoLT]

you need to get the code it's lodging.. then go from there.. sounds like it could be a speed sensor.
ABS Error Codes

[coolngroovy]

Thanks m8
Will check

[HoldrodeoLT]

No worries, make sure you get back to us with the problem/fix... to help the next person with the same fault. cheers

[coolngroovy]

I was actually going to cheat.
I know a bloke that is a Holden mechanic, i'm going to ask him if he can plug it in to the diagnostic machine.

[HoldrodeoLT]

lol well thats even easier haha..goodluck

[VSPantha]

I've got the exact same problem.... apparently caused by speed sensor frequency error... one of the hubs is throwing junk data ~80kms/hr... I asked a mechanic friend about it and got told it'll be one of the hubs! Which hub??? Your guess is a good as mine! Let me know if u get any further info plz

[hako]

It could be the connectors - the ones at each hub. They can get knocked out of position or corrode if not filly pushed in. Also check the main connector to the ABS unit in the engine compartment which can have corroded terminals if water gets into the connnector.

[Cheap6]

As part of a visual inspection of the sensors also look for damage to (all of) the "teeth" of the rotating part (tone wheel).

The gap between the sensor and the tone wheel is also important but probably covered by checking that the sensor is pushed into the bracket. There are shims used to adjust the air gap though and it should be 0.3-1.3mm.

The sensors are wire coils around a permanent magnet so checking for one of the sensors with an open circuit or different resistance to the others can ID a failed sensor. For VP/VQ and VR they should be 600-1600 Ohms. VS will likely be the same.

The sensors generate an AC voltage so a DMM capable of measuring frequency across the (disconnected) sensor wires with the car moving can also ID a dead sensor (but will probably miss one where only one or two of the voltage cycles are missing occasionally => 'scope for those). Calc. the expected frequency using the number of tone wheel teeth, tyre circumference and the road speed.

[coolngroovy]

I've got the exact same problem.... apparently caused by speed sensor frequency error... one of the hubs is throwing junk data ~80kms/hr... I asked a mechanic friend about it and got told it'll be one of the hubs! Which hub??? Your guess is a good as mine! Let me know if u get any further info plz

Yep.....error code 28.
I'm going to have to contact my little mechanic m8 to sort this.

Thanks for the input guys.

[VS5SPD]

Yep.....error code 28.
I'm going to have to contact my little mechanic m8 to sort this.

Thanks for the input guys.

Hey, Did you find a solution this? I'm having the same problem.

[coolngroovy]

No. It lasted about 4 weeks then went away.
It hasn't come back on in months.

[VSPantha]

Mine comes on religiously at 80k's/hr... I think it's coz I've got 60's on the rear wheels and 50's on the front... at 80k's an hour they must be rolling out of sync and throwing the code 28.
I'm just waiting for the tyres to get to the point where they need replacing (they were brand new when I got the car 7 months ago) and then throwing on some 18's and the VE big brake upgrade

[coolngroovy]

Damn! that's it!
The light never came on until i had a blow out, so i put 2 stock rims on the rear which are a much larger profile. Since then i have had the problem.
I swapped the rims a little while back to same size all round, & haven't had an issue since!

Thanks for the mental prompt vspantha. Problem solved.

[VSPantha]

no worries CnG... I've thought that's been the problem with mine although I haven't tested out my theory yet. I hope getting the same profile tyres on mine will fix it all up too