Josiky Posted August 10, 2021 Report Share Posted August 10, 2021 Hello, I need to take ABS Signal from a diff ABS Sensor in a 200sx s13. Is it possible to get the rear differential abs signal to a Digital input and get speed? Then use an aux out to drive the cluster? I'm using a g4x xtreme wirein. I have seen in some topics i can get the diff ring out and trim 1 every 10 tooth, but in that case I'd prefer to buy a dakota sgi which can convert the signal. I believe 200sx s13 abs sensor is magnetic (2 wire) and the ring has 50 tooth. Im using 634mm diameter wheels. In the case getting the abs signal to speed is not possible with link and I buy the dakota, should i wire the abs sensor to the dakota, dakota out to the cluster, then to Digital Input to ecu? or abs sensor to dakota, dakota out to link, aux out to cluster? Thank you so much for your time and attention. Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 10, 2021 Report Share Posted August 10, 2021 Yes connect the ABS sensor direct to a DI. G4X can handle the high frequency no worries. Driving the speedo from the ecu will need a little extra circuit to make it work as the ECU aux output will output a 12V DC square wave, whereas the speedo was designed to be driven from an AC sin wave. I have used the circuit below sucessfully with a skyline speedo before, no guarantees it will work but likely will. Quote Link to comment Share on other sites More sharing options...
Josiky Posted August 10, 2021 Author Report Share Posted August 10, 2021 Thank you. I will try this in the following days. Quote Link to comment Share on other sites More sharing options...
Josiky Posted August 11, 2021 Author Report Share Posted August 11, 2021 Thank you. I will try this in the following days. Edit. I got the abs signal working inside ecu connected to a di. I'm trying the speedo out aux function and won't work. I used the diagram you sent. Picture attached. Tried both cables and nothing. (these are the wires that went to the oem sensor in ca18det gearbox). Tried to use key on sweep but nothing happens. Also tried to drive the car on Jacks till I got speed reading in link. Thank you. Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 11, 2021 Report Share Posted August 11, 2021 You will really need an oscilloscope to diagnose any further. The waveform that is generated by this circuit will be highly influenced by the impedance of the speedo input in the car. As I mentioned I had it working on a Skyline and some other forum users have successfully used it on other nissans but they may not all be the same. Quote Link to comment Share on other sites More sharing options...
Josiky Posted August 11, 2021 Author Report Share Posted August 11, 2021 Hello Adam, thank you so much for your time. What do I need to do with the oscilloscope? I'm really interested into this, so I'm willing to try. I know some people with s13 and s14 has done this with the dakota, using hi-lo signal. Abs input on sensor it and then out 3 to dash. Maybe with that info we could get something closer? Thank you again Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 12, 2021 Report Share Posted August 12, 2021 The speedo will be expecting a "sin wave" type signal that goes above a specific voltage, then falls through zero down to a specific negative voltage. The circuit I provided will generate a crude representation of this, but the voltage it produces and whether it crosses zero etc can be influenced by the characteristics of the speedo it is connected to. So you need a scope to see what the problem is. Yes you could use a commercial device such as the SGI to do it instead of my circuit, it will likely be more widely tested and robust. Just to confirm speedo is working and the wires are connected at the other end, does it show a speed if you connect it directly to the ABS sensor? essb00 1 Quote Link to comment Share on other sites More sharing options...
Josiky Posted August 12, 2021 Author Report Share Posted August 12, 2021 Really appreciate the explanation. Speedo was working before without an issue. I will try on Monday as I'll be out for the weekend. Will get back to you soon. Thank you. Quote Link to comment Share on other sites More sharing options...
mike2016 Posted August 18, 2021 Report Share Posted August 18, 2021 Adam, can this be a solution to R32 with mechanical speedo? the speedo output from cluster to ECU is not usable at all. Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 18, 2021 Report Share Posted August 18, 2021 You would have to try it and see. Most older ABS systems arent too fussy so you can share the signal with the ECU. Some have quite sensative fault detection and wont like having an ECU connected in parallel. Note in the next firmware release that is pretty close to release there are user configurable filters for speed inputs, so that may be enough to give you a workable signal from the speedo depending how bad it is. Quote Link to comment Share on other sites More sharing options...
Josiky Posted February 3, 2022 Author Report Share Posted February 3, 2022 Hello adam, I've been so busy these months. Sorry to refloat the topic, but I hate finding an unfinished topic when im trying to find something for help.I did re use your diagram and worked flawlessly!!! The issue was I had to hook the diagram directly to the dash. I dont know why, but connecting it to the oem sensor cable does not work. There must be something in between. Now im encountering another problem (need to test it yet on the street though): using test pwm or just using the KMH offset i cant manage to get above 180kmh. If i go past it, the needle goes to 0 once again. It seems like the dash is not happy with the high frequency maybe? Thanks a lot for your time. Really appreciate your help. Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 3, 2022 Report Share Posted February 3, 2022 Do the numbers on the dash actually go above 180? You would really need someone to put a scope on it to confirm if the signal is still there and the wave form still looks ok. Quote Link to comment Share on other sites More sharing options...
kaptainballistik Posted February 3, 2022 Report Share Posted February 3, 2022 On 8/13/2021 at 8:10 AM, Adamw said: The speedo will be expecting a "sin wave" type signal that goes above a specific voltage, then falls through zero down to a specific negative voltage. The circuit I provided will generate a crude representation of this, but the voltage it produces and whether it crosses zero etc can be influenced by the characteristics of the speedo it is connected to. So you need a scope to see what the problem is. Yes you could use a commercial device such as the SGI to do it instead of my circuit, it will likely be more widely tested and robust. Just to confirm speedo is working and the wires are connected at the other end, does it show a speed if you connect it directly to the ABS sensor? For the DI, what's the maximum HZ it can take? ( Something in the back of my head says 500hz) Quote Link to comment Share on other sites More sharing options...
Josiky Posted February 3, 2022 Author Report Share Posted February 3, 2022 Hello Adam! Yup numbers on dash go to 240. I will have to find and oscilloscope then. In case the signal gets fucked up with high frequency what would be the solution? Bigger resistance or capacitor? Have to note that I'm using a 220v ceramic capacitor. I believe it does not matter, but just to say. Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 4, 2022 Report Share Posted February 4, 2022 13 minutes ago, kaptainballistik said: For the DI, what's the maximum HZ it can take? 10KHz on G4X. Note this is not relevant to his problem anyway since he is using the test PWM feature on the aux output so the DI isnt even working. 8 minutes ago, Josiky said: I will have to find and oscilloscope then. In case the signal gets fucked up with high frequency what would be the solution? Bigger resistance or capacitor? It is a very crude circuit just to create a signal that cycles above and below zero volts. It worked for me on a Nissan but I dont even know if I ever tested it above 180. A scope capture would give you some clues about what was wrong. Is the signal still there, is it still crossing zero, is the voltage still acceptable, etc. Depending what was wrong then you would try adjusting the circuit from there. kaptainballistik 1 Quote Link to comment Share on other sites More sharing options...
Josiky Posted February 4, 2022 Author Report Share Posted February 4, 2022 Hello I'll first test in on the street and then if it still don't work as intended I'll do the oscilloscope. Thanks a lot Adam Quote Link to comment Share on other sites More sharing options...
Josiky Posted February 17, 2022 Author Report Share Posted February 17, 2022 Hi adam, tried the setup on the street. works very well! i have found another encounter which is quite minor from the ABS sensor / DI8: speeds under 20kmh wont be read by ecu. When 20kmh is achieved, all works as intended. Any ideas? Maybe hz or anything? Thanks a lot for your time once again! I believe this saves everybody spending some money on a dakota unit. Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 17, 2022 Report Share Posted February 17, 2022 The arming threshold is 1.5V on the DI's. Some VR ABS sensors will need some speed to reach that voltage. Quote Link to comment Share on other sites More sharing options...
Josiky Posted February 17, 2022 Author Report Share Posted February 17, 2022 I see. Is there any way the 1.5v could be met before? Thank you. Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 17, 2022 Report Share Posted February 17, 2022 Reduce air gap between sensor and wheel. Quote Link to comment Share on other sites More sharing options...
Josiky Posted February 17, 2022 Author Report Share Posted February 17, 2022 Thank you adam! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.