ABS+ASC module, fault lights and hot wheel...?

[n_mistry]

I’ve been getting intermittent ABS, traction control and parking brake lights come on. When they come on, I turn the car off and start up again and lights disappear, until some random time.

I have noticed that at times there is an odd smell from the front off side wheel after faster driving so I started to think that maybe I’ve got a sticky caliper?

I cleared all error codes (only bought the car last month so wanted to start from a clear log to avoid any confusion from old uncleared codes) and went for some spirited driving last weekend. I got that smell from the same wheel and it was pretty warm around it.

Did some googling and I’ve read that the ABS+ASC module is a common fault and other results point to cleaning/replacing the ABS sensor.

Is it possible that a faulty module or sensor can lead to the overheating and whatever rubbing during rotation to give off the smell from the wheel?

The car is a 2001 Z3 3.0 roadster.

 

[mwpe]

I think the first thing to do is to fix the suspect sticking caliper. take it off and excercise the piston by pushing it in and out a few times, that often cures it. You could use a syringe and squirt a bit of brake fluid behind the seal. The overheating could be upsetting the sensor.

 

[t-tony]

Also check the air gap of the ABS sensor too. I more likely that overheating (mechanical problem) is causing the other (electrical problem). Please keep us posted.

Tony.

 

[Stevo7682]

I would plug your diag tool back in as well if the light has come on since you cleared the codes then the fault will be logged.
See if it's the same wheel as the burning smell that'll help work out if 2 problem are linked or you have 2 separate issues.
Stephen.

 

[n_mistry]

A small update - ABS sensor replaced for same wheel as wheel that was heating up. Going to collect car tomorrow. They said they inspected the caliper and there isn't any drastic seizure but that doesn't explain why it was heating up + the smell. Therefore, I think my best options are to (a) have a look myself and (b) come up to a zedshed and have a look + chat, see what others think?

I'm still convinced the calipers pot/piston need cleaning so I think my next little job will be to change pads, discs and clean the calipers out when it's all apart, as well as a brake fluid change for completeness!

 

[Stevo7682]

Zeds are really prone to seized pistons on calipers .
Might be relatively ok when cold then jamming up when hot and metals expanded.
Stephen.

 

[t-tony]

What Steve said. If they’re not road testing long enough they’ll never replicate the problem. You need callipers or a refurb kits (new piston and seals) also I would definitely do both at the same time.

Tony.

 

[n_mistry]

Yep thanks guys, I did a bit of google and found inspiration from an old post on the forum: https://zroadster.org/threads/sticking-caliper-add-it-to-the-list-sigh.10368/

Went on ECP and reserved a refurbished caliper for £81, I anticipate my one is still good enough for them to take in return so I can try and recover some money!

I'm a researcher in engineering at the uni of southampton and know the technicians quite well so will ask if I can use the formula student garage to switch the calipers, to avoid paying more money to a garage for labour. Just bought a new house and we're planning a wedding so I need to try and save as much money wherever possible!

Will look to replace pads and discs + brake fluid change next month

 

[Stevo7682]

Ecp will take your old unit back for surcharge as long as it does not have casing damage .
Even if totally seized that's fine as long as in one piece.

 

[n_mistry]

Forgot to update/conclude - front driver's side calliper changed, no more excessive heat. Took it to work with me and jacked it up outside the formula student garage and a bunch of automotive engineers were leaving their class. Got plenty of looks and "oh cool a Z3!" - I felt very proud

Seems like that smell from the rusty calliper seizing masked smells from elsewhere because now that no longer smells, I can smell a bit of the same from the passenger's side hahahahah just my luck! It's not terrible so I'll wait until June and change it at the same time as MOT and do discs, pads and new brake oil at the same time.

4 months of owning this guy and I have no regrets and I'm loving the drive, very happy bunny Reminds me of my E46 330Ci, but more fun!

 

[t-tony]

That's the problem with these older cars, that everything is getting to the end of it's working life at the same time. Next thing will likely be the rear callipers, unless they died first.

Tony.