Datatek
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A completely duff sensor would show now signal, it is possible to get a weak signal, but it sounds like your sensors are OK
P38A ABS Fault and Traction failure from ignition II
- Thread starter MikeFl4
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Both videos look the same to me?
Are you getting a voltage readout?
Edit: found the other video, looks ok
Are you getting a voltage readout?
Edit: found the other video, looks ok
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Have you been able to clear the fault codes on the abs/wabco ecu? Everything might actually be fine
Typical, yes, sorry it appears to have the same - here is the other vid
https://m.youtube.com/shorts/Gm4sCVw7hWU
https://m.youtube.com/shorts/Gm4sCVw7hWU
I can clear the codes but that one fault comes back instantly “ecu/reference ground fault” one - since the system self checks every startup - it displays the errors straight away
Lol, this is the one time where it’s unfortunate that the seem ok as I really don’t know what to chase after next. I’ve confirmed the ground points for the abs ecu are going to ground (and are relatively strong). Basics like battery, alternator are all good… connectors are bypassed and soldered. All relevant grounds all checked, cleaned and tightened.
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Other than the single connector that the abs sensor plugs into, there is no other connector in the loom between the ECU and the respective sensor.
I had a sensor that appeared to give valid readouts but was still duff
I had a sensor that appeared to give valid readouts but was still duff
Ok, good to know that there probably isn’t any other connectors that could be causing a problem. I guess the next course of action is to properly check all the sensors resistance and go from there.
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I had a similar problem (Permanent ABS & TC lights) and the Error message was something like "One sensor shorted to another" and it came back immediately after clearing it.
OSF sensor was indicated.
When I checked mine the good ones were all around 1.2kOhms resistance and they were supplied with 5.3V at the sockets they plugged into. The bad one (OSF) was Open Circuit and its connector also had 5.3v supply.
I replaced the OSF one that was showing open-circuit and checked the "stationary" voltages shown by Nanocom.
3 were all identical at 2.3v but the "new" Chinesium one was 2.1v. The ECU was happy however and no faults since.
I hope you find your problem.
OSF sensor was indicated.
When I checked mine the good ones were all around 1.2kOhms resistance and they were supplied with 5.3V at the sockets they plugged into. The bad one (OSF) was Open Circuit and its connector also had 5.3v supply.
I replaced the OSF one that was showing open-circuit and checked the "stationary" voltages shown by Nanocom.
3 were all identical at 2.3v but the "new" Chinesium one was 2.1v. The ECU was happy however and no faults since.
I hope you find your problem.
I had a similar problem (Permanent ABS & TC lights) and the Error message was something like "One sensor shorted to another" and it came back immediately after clearing it.
OSF sensor was indicated.
When I checked mine the good ones were all around 1.2kOhms resistance and they were supplied with 5.3V at the sockets they plugged into. The bad one (OSF) was Open Circuit and its connector also had 5.3v supply.
I replaced the OSF one that was showing open-circuit and checked the "stationary" voltages shown by Nanocom.
3 were all identical at 2.3v but the "new" Chinesium one was 2.1v. The ECU was happy however and no faults since.
I hope you find your problem.
Thank you very much for your input,
Just to ask, the error lights and messages came up straight away when you turned on the ignition? I have never even gotten mine to work properly once since I bought it, so no such thing as an intermittent fault here.
Originally when I bought the car I had the "short to another sensor" code for the FR (OSF). I replaced this with the "allmakes" brand front sensor that you can buy on island4x4 for like £20 and it seems to be fine now (all the same voltages and speed readings in diagnostics) . Once I measure all the sensors manually ill know for certain if there is any sensor related issue!
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Hi there,
When it was putting the ABS & TC lights on it happened more or less as soon as the initial self-test period was over and before starting up. BEEP!!
It definitely did not need a new ECU, none of my wiring needed changing and it was the OSF sensor. Replaced it and all faults disappeared.
This has happened twice now, both times after hitting big, frame-jarring potholes. Seems to be a recurring issue but only on the OSF sensor and it has been fixed (twice) by replacement of that sensor.
You can swap the front sensors over to see if the fault moves with the sensor itself (they are exactly the same). Good hunting!
Hi guys,
Just a quick update for you guys, readings for the abs sensors below ( they all seem fine? )
I don't think I need to explain the picture, its pretty self explanatory I hope - I had the multi meter on the "2K" setting for the ohms readings.
One thing to note, there was a bit of corrosion on the RR sensor - it was giving me an unstable reading on the voltage to begin with. A bit of cleaning and this then all read fine.
FR is the one I replaced on the car (cable was cut in half when I got it) - it all reads fine on diagnostics
Turned the key to ignition II - both Abs Fault and Traction failure up straight away... (you know, after like 2-3 seconds once it completes the self check)
Scanned for codes, cleared all the "short to another sensor" codes (since id only just had the sensors disconnected for testing) and, my favorite code came back right away (it basically never clears) "ECU ground or Reference ground fault" - No other faults present
Don't really know what to chase after next, since all the sensors give an accurate speed reading I don't think its gonna be necessary to remove or tap them in etc
I think I'm just going to have to trust the scanner and delve deep into the grounds/wiring/connectors (ones that I haven't already done - lol not many at this stage)
The last issue I had that was scanner related (check engine light) came up as the needle lift sensor no.4 injector - and the scanner was dead on, replaced that and no CEL since.
Just a quick update for you guys, readings for the abs sensors below ( they all seem fine? )
I don't think I need to explain the picture, its pretty self explanatory I hope - I had the multi meter on the "2K" setting for the ohms readings.
One thing to note, there was a bit of corrosion on the RR sensor - it was giving me an unstable reading on the voltage to begin with. A bit of cleaning and this then all read fine.
FR is the one I replaced on the car (cable was cut in half when I got it) - it all reads fine on diagnostics
Turned the key to ignition II - both Abs Fault and Traction failure up straight away... (you know, after like 2-3 seconds once it completes the self check)
Scanned for codes, cleared all the "short to another sensor" codes (since id only just had the sensors disconnected for testing) and, my favorite code came back right away (it basically never clears) "ECU ground or Reference ground fault" - No other faults present
Don't really know what to chase after next, since all the sensors give an accurate speed reading I don't think its gonna be necessary to remove or tap them in etc
I think I'm just going to have to trust the scanner and delve deep into the grounds/wiring/connectors (ones that I haven't already done - lol not many at this stage)
The last issue I had that was scanner related (check engine light) came up as the needle lift sensor no.4 injector - and the scanner was dead on, replaced that and no CEL since.
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We have had broken teeth on the reluctor ring before.
Would this cause the issue to appear even when the vehicle is stationary with the engine off?
Lol, the odds are that even if I find the electrical issue I could then end up finding several different mechanical faults!
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- Buckinghamshire, UK. ('95 DT)
Don't know if the fault self-clears or not to be honest. I have the 2W TC and so far it has always behaved.
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Have you tried supplying a separate earth to the ecu?
I actually have this written down to try since yesterday, after I made the post I looked at the electrical diagrams for all abs related grounds. All the grounds I had found were ones I’d already super cleaned and tightened.
I have measured from the potitive on the battery to the grounds on the abs ecu - and got a perfect result - solid connection with pretty much no resistance.
I’ll run a dedicated cable to the battery negative today and see what I get.
tomcat59alan
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Datatek
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That is not going to affect things with the car stationary
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Do you have a Nanocom?
When I fixed mine (4-Wheel ABS Wabco-D) the failed sensor was showing a 0v reading on the ECU although it had 5.3v at its supply plug.
When I changed it for a new one it showed a similar Nanocom reading (2.1v Vs 2.3v) to all the others and the fault was fixed.
When you say you have 4.8v in your post above, where was that reading measured/taken from?
When I fixed mine (4-Wheel ABS Wabco-D) the failed sensor was showing a 0v reading on the ECU although it had 5.3v at its supply plug.
When I changed it for a new one it showed a similar Nanocom reading (2.1v Vs 2.3v) to all the others and the fault was fixed.
When you say you have 4.8v in your post above, where was that reading measured/taken from?
