Citing ABS and Tracking lights are ON. Stop-Start stopped working.

[ncsknc]

We hit a few pot holes in the last couple of drives. 🥴

 

 

VCDS reading as below. 

• C101C 14 [137] - Open or Short to Ground

Address 03: ABS Brakes (J104)       Labels: 1S0-614-517.clb
   Part No SW: 1S0 614 517 E    HW: 1S0 614 517 E
   Component: EBC 460 ESP   H08 0012  
   Serial number: A00771D
   Coding: 31BF24718BB002F98CFA24F9D1A94090590100
   Shop #: WSC 05072 004 1048576
   ASAM Dataset: EV_Brake1ESPMP1TRWVW120 016035
   ROD: EV_Brake1ESPMP1TRWVW120.rod
   VCID: 3169A0C36029531B74-8064
1 Fault Found:
0003 - Rear Left Wheel Speed Sensor 
          C101C 14 [137] - Open or Short to Ground
          MIL ON - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 1
                    Fault Frequency: 1
                    Reset counter: 171
                    Mileage: 111348 km
                    Date: 2024.01.30
                    Time: 20:10:04
                    DTC: 00 00 03

 

 

Please tell me this is an inexpensive fix! 

I tried looking at my rear wheel, doesn't seem like a puncture. Not sure what open/Short to Ground means. Would it mean the connector to the sensor might have come undone? 

 

I am not able to reach with my hands into the back of the wheel. Looks like the only solution is to remove the wheel which I have never done. there is a screw jack in the back and tools. Worth removing the wheel myself?

Any suggestions please?

 

Is there anyone in London that can help out? I am near Wandsworth. Thanks.  

[ncsknc]

IMG_0158.HEIC IMG_0161.HEIC IMG_0166.HEIC

[ncsknc]

Would appreciate some help please

[Warrior193]

Hello, it's likely that the ABS sensor or the connecting lead has been damaged, the wheel will need to be removed to check it. 

[freemansteve]

Any garage can fix this in under an hour, assuming the sensor needs changing (£25?). Could the connector as said.

[ncsknc]

Great. Thank you both. I was trying to be brave and studying how to remove the wheel myself. Looks like when we are putting it back on, I need correct torque to be set. I can't just stand on the level to tighten it. Lol. 

Taking to a garage in thr weekend. 

[Warrior193]

What you need is a long 'breaker bar' with correct size socket for loosening tight wheel bolts - which may have been previously tightened way too much by gorilla with a hammer-gun. 

Ideally, the bolts require to be refitted at correct torque, but this can be reasonably estimated with a little experience.

It's good practice to have a 'feel' for the correct wheel bolt torque - it's a real pain to find that you can't replace a flat at the roadside because some gorilla tyre fitter has wound the hammer-gun to max!  

[ncsknc]

Sorry. We have been moving houses (way too many clothes and boxes! And the cat ran away on first day giving us a nightmare and came back at  midnight!)

and this has been moved to lower priority. 
 

Thought this warning light will go away on its own after few drives (like last time) but didn’t. 
 

I have to attempt at least once before going to a mechanic and say please remove my wheel so I can slightly press on the speed sensor. (Perhaps I have to replace just one in that wheel)

I think I was quoted £90 on https://www.fixter.co.uk for replacement of the sensor in 1 wheel. Don’t know how legitimate they are. 

[ncsknc]

Just loosened all the nuts and I have angered the sky man. Raining here. This is going to a long day 

[Warrior193]

1 hour ago, ncsknc said:

Sorry. We have been moving houses (way too many clothes and boxes! And the cat ran away on first day giving us a nightmare and came back at  midnight!)

and this has been moved to lower priority. 
 

Thought this warning light will go away on its own after few drives (like last time) but didn’t. 
 

I have to attempt at least once before going to a mechanic and say please remove my wheel so I can slightly press on the speed sensor. (Perhaps I have to replace just one in that wheel)

I think I was quoted £90 on https://www.fixter.co.uk for replacement of the sensor in 1 wheel. Don’t know how legitimate they are. 

Glad that puss got back home safely. 

Edited 18 February by Warrior193
typo

[ncsknc]

41 minutes ago, Warrior193 said:

Glad that puss got back home safely. 

Ah thanks! He is ground for few months now. Until he gets used to the house and feel safe. 


I was able to remove the wheel, remove the clip on the cable, clear the female part of the cable from the computer, remove the nut for the sensor, take out the sensor and clean it. 

Gives me the exact same error! 

 

0003 - Rear Left Wheel Speed Sensor 
          C101C 14 [137] - Open or Short to Ground
          MIL ON - Confirmed - Tested Since Memory Clear

the contacts are clean already. No obvious signs of rotor hitting the sensor plastic, I guess that eliminates the rotor damaged for now. 

 

• Not quite sure what Open or short to Ground means. A break in the cable? 
• May I ask if you know where the cable from the wheel ends, would there be a contact issue on the other end to the vehicle computer?

• I could try buying a new sensor (hope they have a return policy! ).
• Trying to find a cheap multimeter to test if the cable to the wheel has voltage. 
• Wait, Rear left wheel is passenger side or driver side. I checked just the passenger side rear wheel 

 

Edited 18 February by ncsknc

[Paws4Thot]

48 minutes ago, ncsknc said:

Ah thanks! He is ground for few months now. Until he gets used to the house and feel safe.

Easy answer - butter his paws to stop him running away, as per Thelwell's Magnificat!  

[freemansteve]

1 hour ago, ncsknc said:

Not quite sure what Open or short to Ground means. A break in the cable? 

• May I ask if you know where the cable from the wheel ends, would there be a contact issue on the other end to the vehicle computer?

• I could try buying a new sensor (hope they have a return policy! ).
• Trying to find a cheap multimeter to test if the cable to the wheel has voltage. 
• Wait, Rear left wheel is passenger side or driver side. I checked just the passenger side rear wheel 

 

 

 

Open means either one or more conductors has gone open circuit, i.e. is no longer connected to the ABS controller, maybe cut.
Short to Ground means a wire that should have a signal is connecting to the chassis, or some to metal, possibly trapped or stripped insulation.

If you buy a sensor and try it, you won't be able to return it.

No point in a multimeter unless you know where the wires start and terminate for checking continuity. You may be able to check if the sensor internally shorted or open circuit.

"Left rear" is on the left from the point of view of your left when sitting in the car.

Chances are it's a faulty sensor. Buy one from an internet shop.

[ncsknc]

10 minutes ago, freemansteve said:

 

 

Open means either one or more conductors has gone open circuit, i.e. is no longer connected to the ABS controller, maybe cut.
Short to Ground means a wire that should have a signal is connecting to the chassis, or some to metal, possibly trapped or stripped insulation.

If you buy a sensor and try it, you won't be able to return it.

No point in a multimeter unless you know where the wires start and terminate for checking continuity. You may be able to check if the sensor internally shorted or open circuit.

"Left rear" is on the left from the point of view of your left when sitting in the car.

Chances are it's a faulty sensor. Buy one from an internet shop.

okay thanks.  Ordering one now. 

[ncsknc]

Digging a bit deeper, I was able to see real time log on the measuring tool.

 

Rear left stays zero. 😔

 

I am hoping the failed component is just the sensor. Ordered one and waiting for the delivery. 

It is a bit strange, sensor is the non moving component with just a magneto resistor, and how it fails. The only explanation I have is moisture corrosion but I don't see any obvious signs of corrosion getting inside the contacts. 

[freemansteve]

The (rotating) reluctor ring might be a problem, but I bet it's the sensor.

[ncsknc]

Thanks. Still waiting on the order! Can't wait and hope the weather improves so I can get this done when it delivers. It's wet all around and missus will not be please if the car is out of commission for too long. 

Found another thread that talks about battery being an issue. Doubt it in my case, it's a new start/stop battery replaced in 2022. Having said that, would constant start stop some how burns through the sensor resistor? I am presuming it's the resistor type sensor or a small copper coil that get's magnetised with DC current from battery. 

All in all, this is a fascinating and simple tech.
 

* ABS sensor

* Reluctor ring

* Battery. 

 

[freemansteve]

I've heard that a battery affects ABS sensors. A duff battery can play havoc with electronics, but your issue seems to be a specific, consistent and isolated fault.

Although some ABS sensors are "coil on magnet" types, like a guitar pickup, I think most modern ones use Hall sensors, and these are usually just an IC (no coils).

[HeavyMetalRich]

The sensors can be susceptible to damage from hard jolts of the kind you get by running through a pothole. If you're really unlucky, the reluctor ring could have de-magnetised too. But I think replacing the sensor will solve your problem.

[freemansteve]

It's pretty hard to see how "jolts" and potholes would damage an ABS sensor directly....
 

The most likely problem is that the ABS sensor on these cars is they use a chip-based Hall sensor that has failed,  possibly by water ingress. Or the reluctor ring is clogged with road gunge that reduces the signal level.

 

The reluctor ring on these cars is toothed ("castellated" if you prefer), and not magnetic. There is a magnetic element in the sensor that creates a signal whose amplitude varies according to the metal mass passing under it - analogous to an electric guitar string and a guitar pickup (n.b. the moving string is not magnetized, it just alters the field in the pickup).

Edited 26 February by freemansteve

[ncsknc]

Hi

 

i have replaced the sensor the problem with same error is still there. Sadly. 
 

I have measured the voltage on incoming cable in the problem rear left wheel, it says just under 2V. Should this be a 2V? 
 

I am removing the other rear wheel now to check how much it says there. 
 

is there a fuse per wheel for ABS sensors? Could that be an issue?

[ncsknc]

I am so sad right now. I think the locknut has stripped trying to remove the right rear. All 4 bolts were too tight. 
I am pretty sure it said just under 2V ingnition on, on the problem rear left wheel . 

 

 

[freemansteve]

What state is the reluctor ring in?

Voltages won't tell you much.

There are no locknuts for the wheels, only bolts (4).

Edited 28 February by freemansteve

[ncsknc]

Probably too simply of a question, is there a guide or a video or a brief description of how to check the reluctor ring? What it should look like, comparing a healthy and broken one? 

 

I meant locking wheel nut sorry. I am unable to remove the right rear. can try rear left. 

 

Found a video where the cable is damaged. Not sure if that is something that has happened to me. Falla Sensor ABS/ VW UP / Skoda Citigo / Seat Mii ABS Wheel Sensor / Code C101B14 (youtube.com)

[freemansteve]

yes cable damage is a possibility - if the sensor is (as I think) chip-based, it's hard to say if 2V is meaningful; the cable to the ABS unit is at least not open-circuit...

I think the reluctor ring can get clogged or corrode, but you'll have to be up for disassembly of the rear hub and drum brake. If you cannot remove the RHS rear wheel, I suspect you may not have the tools to do a hub disassembly, but any decent independent garage will be able to.

I assume you have you disconnected and reconnected the battery for a reset, and driven the car 1/2 mile, in case the new sensor needs to be recognized by the system - I don't know whether you have to reset error codes, but probably, so check this first with a garage.

For tech help, the Up Owners Club has far more members and quite a few genuine tech people on it..... The Up is the same car as a Citigo.