ABS Code 16 Electrical Noise/Intermittent Interruption

Max · Post by **Max** » Wed Sep 13, 2017 8:14 pm

Hi Guys,

I am getting the above code on my Type S, it came up when i performed the ATTS oil inspection procedure, so with the front wheels off and the car on stands i run the car at 31mph for 1 minute and the code appears. But it also came on and off during a normal drive...

Trouble shooting I've been through:

- Tested sensor resistance which is within spec
- Tested all other sensors resistance and found all to give a very similar reading ~1390 ohms
- Tested sensor resistance at the ABS ECU plug all good
- Checked the pulsar ring which is clean and not loose
- Checked the sensor didn't have any debris on it
- Checked the sensor is close enough to the pulsar ring
- Sanded the sensor mounting surface on the hub down a bit to bring it closer to the ring
- Checked there isn't a short between the + terminal of the sensor and all other sensor + terminals at the ecu plug
- Swapped the sensor for another known good working one (bought a used one off ebay) but after running the ATTS oil inspection procedure again the same code appears

Aside from getting my hands on another Active ABS ECU I'm at a loss, is there any other way i can pinpoint the problem?

Other options I've thought about are somehow measuring the signal output but I'm not sure that will get me anywhere.

Any other ideas?

Cheers
Max

Scott560 · Post by **Scott560** » Wed Sep 13, 2017 8:58 pm

sounds like you have tested quite a lot. Without knowing exactly what that code means - id start to think problems inside the ECU or possibly a crack in the reluctor ring.

The only way to 'view' the output of the sensor is via an oscilloscope but even then that doesnt necessarily corroborate the ECUs view of matter.

Im guessing the ABS and ATTS are inherrently linked together somehow , which may complicate matters compared to a normal just ABS on its own setup? Generally ABS ECUs are fairly reliable from my experience, the only failures being sensors going kaput, rings cracking or the abs motor failing.

Have you tried unseating the ABS ECU connector a few times?

Post by **RattyMcClelland** » Wed Sep 13, 2017 10:01 pm

You haven't mentioned the most basic this first.
Reset the abs with the code connector connected and pressing the brake pedal etc etc
If any wheels is in the air whilst another is spinning atts and and throw a code.

Reset ab.s. And if it returns take out the sensor and clean or replace.

Usually solves it.

Max · Post by **Max** » Thu Sep 14, 2017 1:23 pm

Scott560 wrote:sounds like you have tested quite a lot. Without knowing exactly what that code means - id start to think problems inside the ECU or possibly a crack in the reluctor ring.

The only way to 'view' the output of the sensor is via an oscilloscope but even then that doesnt necessarily corroborate the ECUs view of matter.

Im guessing the ABS and ATTS are inherrently linked together somehow , which may complicate matters compared to a normal just ABS on its own setup? Generally ABS ECUs are fairly reliable from my experience, the only failures being sensors going kaput, rings cracking or the abs motor failing.

Have you tried unseating the ABS ECU connector a few times?

Well in simple terms I think the ABS ECU is saying it can see a signal but its not what its expecting.

Regards viewing the signal yes that's exactly what I was thinking it not necessarily going to tell me which end is at fault.

I'll double check the pulsar ring and yes ive unseated the connector several times to double check the readings on a multimeter

Max · Post by **Max** » Thu Sep 14, 2017 1:30 pm

RattyMcClelland wrote:You haven't mentioned the most basic this first.
Reset the abs with the code connector connected and pressing the brake pedal etc etc
If any wheels is in the air whilst another is spinning atts and and throw a code.

Reset ab.s. And if it returns take out the sensor and clean or replace.

Usually solves it.

Sorry yes fairly key piece of info, I have reset the code a few times before re-running the oil inspection test to see if it would reappear.

So are you saying its possible its throwing a code just due to the nature of the test? The first time this happened I have the whole car up on stands, the last time i ran the test i had just the front wheels off the ground. So in both cases the rear wheels were not moving, is it possible its throwing a code just because of that? I would have thought the manual including the ATTS info guide would make some mention of this.

Post by **RattyMcClelland** » Thu Sep 14, 2017 1:40 pm

Wait hold the phone.

So you're not physically driving the car? Just stationary with wheels in the air.

If so.

Ignore all codes. Reset and go for a drive and see if they return.

Put the car on a dyno...atts a throws a wobbly.
Put the car on an mot brake test..atts throws a wobbly.
Different size tyres front to back...atts throws a wobbly.

Very sensitive system, like dale Winton and beef.

Max · Post by **Max** » Thu Sep 14, 2017 1:56 pm

No I'm doing everything as per the manual cos im a weirdo like that, if the manual said stand on one leg id do it lol

Hmm maybe this is just wild goose chase then, its just odd that it keeps throwing the same code for the same sensor every time, that's what makes think there is something behind it.

Ok well maybe ill just clear the code again and see if it returns from normal driving...

Post by **RattyMcClelland** » Thu Sep 14, 2017 3:21 pm

Max wrote:No I'm doing everything as per the manual cos im a weirdo like that, if the manual said stand on one leg id do it lol

Hmm maybe this is just wild goose chase then, its just odd that it keeps throwing the same code for the same sensor every time, that's what makes think there is something behind it.

Ok well maybe ill just clear the code again and see if it returns from normal driving...

Thats the ticket. I had 5 ABS codes on mine.. Wiped it and then took for a drive now i only have one code which is the yaw sensor i removed after i deleted ATTS. Turns out active abs needs the yaw sensor.

Max · Post by **Max** » Wed Sep 20, 2017 8:43 pm

Well i don't want to jinx it but it seems like this really was a non issue and just the ABS freaking out over only the front wheels moving, still doesn't make sense why it picked on that sensor, you would expect it to have flagged both rear sensors...

Anyway after resetting the code and driving to PAW the code didn't come back, Rich did various unrelated bits and bobs for me and also ran an ATTS function test, everything checked out, drove it back from PAW and still no code