I'd rather get a sensor from the junkyard than some off brand one

 

i probably would too, if i have to choose between junkyard and ebay.
i did change my NR2 sensor (trifecta issue) from FCP

 

I've changed too many faulty original equipment sensors on my E46 including cam intake, cam exhaust, oil level etc.
German electronics are bad.

That said, I think if I were in your situation i would have a stealership replace my brake fluid.
You need it done anyway and the process of changing that fluid may resolve your issue.




podman

 

why stealership? can't this be done yourself?

 

Two man or pressure bleeder and one person will solve that.

 

Hah watched that video yest

 

Mine has exactly the same issue, usually on a warm day too, with the pressure difference of about 4-5 Bar Sensor 1 sits at about -0.4 Bar and Sensor 2, which is the one in fault says 4-5 Bar.

I noticed removing the plug from the ABS unit altered the pressure shown so I'm guessing it's a faulty sensor and I have bought one secondhand from eBay for £15, It has been delivered and reads about the same as the other (good) one when in free air but I have't had time to fit it yet. Will let you know when I do.

I did wonder if there was some residual pressure in there though. Mine was flushed about 16 months ago at the MOT test but I don't know if they activated the ABS pump, I'm guessing not. There are no sticking calipers or other braking faults on the car.

 

@cp2708 - wow! Amazing, another 325ver in London with the exact same problem as me. I'll be extremely grateful if you post here how you get on with the sensor change - I just checked it again and it's also sensor 2 for me. I notice it seems to happen when hydraulic temp is 16C or higher. I last had the flush done at an independent - I wonder whether the ABS pump was done or not. If your sensor doesn't do it, I'll take it to BMW Park Lane and let you know how I get on with a flush.

Everyone else - 200+ views and not a single one has dared try a cheap DSC pressure sensor? Come on people, I mean 3x for original is OK, but 10x is just egregious. If i end up changing sensors I'll use the cheapos just so the community learns something - that's gotta be worth the risk.

 

I'm not sure about the temp of the fluid, but historically it has set the alarm when stood in traffic on a very hot day, then goes off when everything else has cooled down. It has done this since I bought the car in Jan 2014, once or twice a year, so it hasn't bothered me too much. It has started to get worse now though triggering twice last month, but was off the last time I drove it.

My mate works in the AA and told me never to buy cheap/reproduction sensors as they're generally no good, so as I've never had an issue with sensor 1 over the 5 years I've owned the car, I thought I'd give a second hand one a try at £15 rather than fork out for a new genuine one.

I'm doing a large PM on the car in within the next few weeks when I go up to Mums so hopefully will get it fitted then and give some feedback.

 

Interesting thanks - it sounds like an absolutely identical picture - I bought the (2004) car in 2016 and have seen this once or twice a year, also exactly on a hot day in traffic. And then it would go off when it cools off. But this year it's started doing it a lot earlier in the year so I think it is getting worse. Given the similarities, there's a good chance it's some age related degradation in the sensor.

 

That's what I'm going for, as I said i'm fairly sure there's nothing wrong with the hydraulics.

 

Just out of interest, what is the build date for yours? Mine is 19/05/04. It is a coincidence that they've both let go in exactly the same way and time frame.

 

RealOEM says Feb 2004 based on the VIN so not too far off yours.

 

Might be different but not sure why you've focused on pressure sensors. Did you clear and read codes when the error displayed again? If not, recommend doing so. Had similar error that only showed after an ~hour drive ***8212; sooner on hot days (i.e. heat related). Over time, the time to error became shorter and error more frequent. Finally cleared all codes and drove with the laptop and BMW Scanner in the car until the error triggered and then read codes. Trapped the key error "control unit internal failure". Replaced ABS module, and all is well. Here's my thread. GL

 

Hi, just an update.

I’ve changed the sensor, attached are a before and after sensor readings on the INPA. It was fairly easy to do, I couldn’t get the bleeding using the pump to work, didn’t try too hard, just got Dad to help me do it the old fashioned way.

Done over 100 miles since and the error hadn’t come back and brakes are good.

Sent from my iPhone using E46Fanatics mobile app

 

Thanks for that and great to hear you've got it fixed. I got the cheapest sensors I could from eBay - £21.50 delivered for a pair and will attempt to get them fitted, probably by a garage. And then I'll report. Out of interest, how did you manage to change them? Did you remove the fluid reservoir? I've tried getting my hands in there and I can't for the life of me imagine changing them both without fluid going everywhere, and even then I'm not sure I'd be able to reach them. so I'm more inclined to leave with a garage.

 

No worries. I got my sensor from Quarry motors in Sheffield, it was £14.50. I tried it in free air to make sure there were no error codes before fitting it.

I syphoned out as much fluid as possible, then opened a couple of bleed nipples to let gravity do the next bit. I removed the brake pipe above the sensor using an 11mm spanner at both ends then it was easy to get a 27mm open ended spanner on the sensor. I did spill some fluid but had put some rags underneath. It was just a case of bleeding them then. Which I did by the press/release method. I’ve since driven 180 miles back to London, no issues.

Sent from my iPhone using E46Fanatics mobile app

 

Well, similar to cp2708 I changed my sensors and 300 miles of warm summer driving (which previously would almost certainly have triggered the DSC light on) later on there's no DSC error. So it appears highly likely that the OEM stock pressure sensors have a gentle failure mode where they begin to give intermittent out of whack pressure readings as they age which appears more frequently in warm weather.

I also replaced the sensors with the absolute cheapest ones I could find on eBay at less than 1/8th the cost of the OEM sensors (I paid sub $20 each). I'll post if I get any issues with them, but so far it seems to be working. Feel free to post here if you want to know how I'm getting on by the time you read this.

 

I replaced my sensors with cheap sensors off amazon. https://www.amazon.com/gp/product/B07JHDWHP4 They fixed my DSC. I haven't done much driving with them yet though. I bled my brakes with a pressure bleeder and ISTA to bleed the pump. According to the service manual, our cars can not be properly bled without software.

 

I replaced my sensors with cheap sensors off amazon. Amazon.com: New Pressure Sensor - Fits 325Ci BMW E46 E60 E61 E64 Z4 34521164458 (2001-2006) Anti-lock Brake: Automotive They fixed my DSC. I haven't done much driving with them yet though. I bled my brakes with a pressure bleeder and ISTA to bleed the pump. According to the service manual, our cars can not be properly bled without software.

Well, similar to cp2708 I changed my sensors and 300 miles of warm summer driving (which previously would almost certainly have triggered the DSC light on) later on there's no DSC error. So it appears highly likely that the OEM stock pressure sensors have a gentle failure mode where they begin to give intermittent out of whack pressure readings as they age which appears more frequently in warm weather.

I also replaced the sensors with the absolute cheapest ones I could find on eBay at less than 1/8th the cost of the OEM sensors (I paid sub $20 each). I'll post if I get any issues with them, but so far it seems to be working. Feel free to post here if you want to know how I'm getting on by the time you read this.

How have the cheap China sensors been so far? I'm planning to get a pair as well. The originals are 18x the price in my country.

 

Mine has been problem free since May. Not actually driven it that far since though.


Sent from my iPhone using E46Fanatics

 

18 months so far and absolutely no problems whatsoever with the cheap DSC sensors.....

 

320Ci from 2004 here. I had a faulty sensor 1 so I've changed both of them as I purchased the cheap ones from ebay. After 600km no problem at all. There is a way to know if one sensor is faulty (at least the sensor 1 I had) which is by driving with the cruise control on , before it was faulty I could disable it just by slightly touching the brake pedal. After I got the error I had to press the brake pedal a little bit further to disable the cruise control . Now everything is working fine.

 

There is a way to know if one sensor is faulty

Best way to determine a faulty sensor is looking at its live data and fault codes using INPA.

 

Did not work for me, just two cheap ones flush’s and bleed the brake fours days later same back. Check inpa no movement.
Order two OEM ones since 2020 no issue.
I have three OEM lift brand new PM if you want them I give you a fair price

 

I was ready to buy brand new OEM ones but decided to try the cheap ones from China and so far after almost 2 years and 20000km of spirited driving, no issues at all.