ESC problem with new brakes and tyres
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Author:  eldavo [ Sun Sep 15, 2019 3:58 pm ]
Post subject:  ESC problem with new brakes and tyres

Hi there, Im hoping someone may be able to help me out.
I have a 2014 dmax 4wd, I have just fitted new front brake discs, pads and wheel bearings, ( all non genuine parts used)I also fitted new rims and brand new tyres at the same time, 265/75/16 (previous 245/70/16). On test drive after fitment as soon as I started driving the ESC light comes on and tries to brake for me and reduces my throttle to idle only. I cant even get up my driveway. If I turn both ESC and TCS the car drives fine but with them on I cant drive above idle or the ESC activates. Any ideas on what the hell Ive done? Ive pulled the wheels off and checked the brakes etc but all seems ok. Its got me stumped.

Author:  mydmax [ Sun Sep 15, 2019 5:25 pm ]
Post subject:  Re: ESC problem with new brakes and tyres

To do that work you have to have had the ABS sensors either unbolted from the steering supports or when you worked on it you have stretched the wiring to oblivion and now one or more aren't communicating with the ECU anymore. Best to unplug the connectors and check the continuity of each front ECU sensor with a multimeter reading OHMS. Also check if they were unbolted that each side is properly seated and running close to the sensor rings.
Also if discs were off, perhaps the sensor rings are not on the inside of the new discs OR if fitted, they have a different slot count to the originals.

IF you replaced the wheel bearings you may have dislodged the sensor rings or bent it somewhere. If so it will not register on the ABS sensors as it's surface slots will be too far away in some patches and not be able to create sufficient magnetic alteration in the sensor. Therefore the ECU will detect an anomaly and refuse to recognise normal operation.

Author:  eldavo [ Sun Sep 15, 2019 7:23 pm ]
Post subject:  Re: ESC problem with new brakes and tyres

Thanks my dmax for your reply. I didnt need to touch or go near the abs sensors as the hubs and rotors were removed and the stub assembly that houses the sensors stayed in place. I had to remove the sensor rings but were pressed back into place on the original bearing hubs. There are no codes showing either, I too thought the abs sensor or ring but thought I would at least get a fault code.
I disconnected the battery for a while and now it lets me drive it but the ESC light stays on. It comes on about 15 seconds after starting the car, even when still in Park with hand brake on sitting still. I think I might have to strip it and have a look.

Author:  mydmax [ Sun Sep 15, 2019 8:31 pm ]
Post subject:  Re: ESC problem with new brakes and tyres

If the battery has been disconnected, then the ABS light will illuminate for a while until the system detects normality. May take a few km's of driving to do that. Seeing you had the slot rings off, are they just clearing the sensors, ie, close enough and are they fitted squarely? If the slots vary away from the sensor, it will know it is there and reading what it is fed and the sensor isn't at fault, but the pulse count per rev will not be correct, ie some missing. That is a possibility. If any grease is present and the rings are holding any metallic dust or crap, it can also alter the count.
Even if one or two bars of the slots is depressed a bit the count will be wrong and not match other wheel rates. That is what the system does after battery disconnect, checks for normal. If there is a constant variation it won't decide to work and constantly indicate.
Is it possible one ring is fitted back to front and the plane of the ring looks ok but is not close?

Author:  eldavo [ Wed Sep 18, 2019 7:26 am ]
Post subject:  Re: ESC problem with new brakes and tyres

Hi mydmax, you wouldnt happen to have a workshop manual or photo showing the front rotors with the abs rings attached. Theres a good chance Ive refitted them both inside out. Its the first car Ive worked on thats got the ring on the hubs, Ive normally only seen them on the outer cv joint. I obviously didnt take enough notice. The way I fitted them looked like the right way and they pressed on nicely. The abs light is now on so Im thinking I may have definitely messed up the rings.

Author:  mydmax [ Wed Sep 18, 2019 8:30 am ]
Post subject:  Re: ESC problem with new brakes and tyres

I will try and find a picture/schematic of the front hub. it will be an earlier version though if I find something. The ABS sensor length from it's bolt flange can be measure so you know it's length, therefore the slotted ring has to be running close to it. If you remove one or both of your front sensors and know that sensor length, at the same time you can measure the depth to the slot ring. I presume it runs with no more than 1mm clearance so magnetic flux detection can happen.
If you measure to the ring and find it is quite a bit more OR uneven each side, give a little tolerance there, that may reveal which side is not quite right or both sides needing attention.
Cheers, Hope you sort it soon.

Author:  mydmax [ Wed Sep 18, 2019 9:38 am ]
Post subject:  Re: ESC problem with new brakes and tyres

I can't get a view small enough to load onto the site, but the slotted ring is annular as you know and the hollow side, ie, edges of the ring face should be fitted with those edges toward the hub flange and the slightly rounded corners of the ring to the sensor side. Therefore, smooth side to face the sensors. It will make a difference of at least 4mm closeness if fitted the other way around.
If you check the gap as mentioned previously by depth probing the sensor hole, it should be able to be determined if the rings are correct or not.

Author:  mydmax [ Wed Sep 18, 2019 3:01 pm ]
Post subject:  Re: ESC problem with new brakes and tyres

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