# Canbus problems **URL:** \ **Category:** MaxxECU\ **Created:** [August 28, 2026, 10:32am UTC](https://forum.realdash.net/t/canbus-problems/11106 "2026-08-28T10:32:14Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![LarsHultman](https://forum.realdash.net/letter_avatar_proxy/v4/letter/l/a88e57/32.png) [@LarsHultman](https://forum.realdash.net/u/LarsHultman)\ **Post date:** [August 28, 2026, 10:32am UTC](https://forum.realdash.net/t/canbus-problems/11106/1 "2026-08-28T10:32:15Z")
Hello! I have a maxxecu mini, and use a meatpi usb can adapter. I have a problem and not all values are broadcasted to realdash. I am missing oil pressure. I have an oil pressure “tab” in realdash under debug view, but no info is sent on it, at all. In Mtune the oil pressure displays correctly. All other sensors, iat, CLT, EOT etc. work and sends info correctly to realdash. I do not understand what could be the problem with the oil pressure, I would assume there is some problem with the Canbus connection, but I have too little knowledge on the subject to problem solve ☹ ---
**Author:** ![laurens226](https://forum.realdash.net/letter_avatar_proxy/v4/letter/l/a5b964/32.png) [@laurens226](https://forum.realdash.net/u/laurens226)\ **Post date:** [August 31, 2026, 6:56pm UTC](https://forum.realdash.net/t/canbus-problems/11106/2 "2026-08-31T18:56:09Z")
Dont think this is a physical CAN bus issue otherwise there would be no data at all. You can add custom data in the maxx can protocol, you could try if then your oil preseure is correctly received. Which protocol did you use in the maxx? Im using 1.3 with no issues ---
**Author:** ![LarsHultman](https://forum.realdash.net/letter_avatar_proxy/v4/letter/l/a88e57/32.png) [@LarsHultman](https://forum.realdash.net/u/LarsHultman)\ **Post date:** [August 31, 2026, 7:38pm UTC](https://forum.realdash.net/t/canbus-problems/11106/3 "2026-08-31T19:38:14Z")
I am using 1.3, yes, both in Mtune and realdash (only option available in realdash) I have no knowledge of adding custom data to a can protocol, or how I would go about doing that. ---
**Author:** ![realdashdev](https://forum.realdash.net/user_avatar/forum.realdash.net/realdashdev/32/6_2.png) [@realdashdev](https://forum.realdash.net/u/realdashdev)\ **Post date:** [September 1, 2026, 7:15am UTC](https://forum.realdash.net/t/canbus-problems/11106/4 "2026-09-01T07:15:24Z")
Oil pressure should come in with default CAN 1.3 output of MaxxECU. One thing to check is if there is some sort of custom mapping active for the oil pressure in RealDash. Go to: Settings-\>Units & Values-\>Value Mapping and remove any mappings for engine oil pressure (if present). ---
**Author:** ![LarsHultman](https://forum.realdash.net/letter_avatar_proxy/v4/letter/l/a88e57/32.png) [@LarsHultman](https://forum.realdash.net/u/LarsHultman)\ **Post date:** [September 1, 2026, 8:15am UTC](https://forum.realdash.net/t/canbus-problems/11106/5 "2026-09-01T08:15:03Z")
There was a mapping for simulated oil pressure which Is removed. When it was mapped to simulated it showed a value, but it was not correct according to Mtune When I removed the mapping the input still shows under debug view as oil pressure, but no value comes through at all. ---
**Author:** ![realdashdev](https://forum.realdash.net/user_avatar/forum.realdash.net/realdashdev/32/6_2.png) [@realdashdev](https://forum.realdash.net/u/realdashdev)\ **Post date:** [September 1, 2026, 10:24am UTC](https://forum.realdash.net/t/canbus-problems/11106/6 "2026-09-01T10:24:52Z")
> [@LarsHultman](#): > > When it was mapped to simulated it showed a value, but it was not correct according to Mtune Yes, because it was simulated, not real oil pressure. What does it mean “no value comes through at all”? It shows 0 all the time? Or the value does not appear in Debug Data View at all? ---
**Author:** ![LarsHultman](https://forum.realdash.net/letter_avatar_proxy/v4/letter/l/a88e57/32.png) [@LarsHultman](https://forum.realdash.net/u/LarsHultman)\ **Post date:** [September 1, 2026, 10:44am UTC](https://forum.realdash.net/t/canbus-problems/11106/7 "2026-09-01T10:44:32Z")
I do not remember exactly, but I will check when I get home, if I remember correct it just says “engine oil pressure : 0”, all the time. When I try to use USB connection directly to MaxxECU engine oil pressure does not show up at all under debug view, only when using CAN connection via the Meatpi. ---
**Author:** ![ElaraHong](https://forum.realdash.net/letter_avatar_proxy/v4/letter/e/8edcca/32.png) [@ElaraHong](https://forum.realdash.net/u/ElaraHong)\ **Post date:** [September 8, 2026, 6:16am UTC](https://forum.realdash.net/t/canbus-problems/11106/8 "2026-09-08T06:16:55Z")
For CAN bus issues, I’d first verify the bitrate and CAN-H/L wiring, then check whether you’re actually seeing valid frames with a CAN monitor. If the frames look correct but RealDash still isn’t picking them up, checking the selected CAN interface and protocol settings would be my next step. ---
**Author:** ![LarsHultman](https://forum.realdash.net/letter_avatar_proxy/v4/letter/l/a88e57/32.png) [@LarsHultman](https://forum.realdash.net/u/LarsHultman)\ **Post date:** [September 8, 2026, 6:56am UTC](https://forum.realdash.net/t/canbus-problems/11106/9 "2026-09-08T06:56:44Z")
I rewired the oil pressure sender to another input on the ecu and now it works. No idea what is going on, but this input I used was not broadcasted via CAN as it seems. ---
**Author:** ![LarsHultman](https://forum.realdash.net/letter_avatar_proxy/v4/letter/l/a88e57/32.png) [@LarsHultman](https://forum.realdash.net/u/LarsHultman)\ **Post date:** [September 8, 2026, 6:59am UTC](https://forum.realdash.net/t/canbus-problems/11106/10 "2026-09-08T06:59:36Z")
This way I did loose another sensor though, so I would still like to find a solution if possible. ---
**Author:** ![LarsHultman](https://forum.realdash.net/letter_avatar_proxy/v4/letter/l/a88e57/32.png) [@LarsHultman](https://forum.realdash.net/u/LarsHultman)\ **Post date:** [September 8, 2026, 7:01am UTC](https://forum.realdash.net/t/canbus-problems/11106/11 "2026-09-08T07:01:24Z")
This is all greek to my, sorry. I am not a tuner, I am a driver, unfortunently 🙂 ---
**Author:** ![LarsHultman](https://forum.realdash.net/letter_avatar_proxy/v4/letter/l/a88e57/32.png) [@LarsHultman](https://forum.realdash.net/u/LarsHultman)\ **Post date:** [September 8, 2026, 7:03am UTC](https://forum.realdash.net/t/canbus-problems/11106/12 "2026-09-08T07:03:56Z")
I will try to have my tuner check over this when I leave my car next time, but since they have no knowledge of realdash, they would rather not, unfortunently. ---
**Author:** ![Albervil](https://forum.realdash.net/letter_avatar_proxy/v4/letter/a/5fc32e/32.png) [@Albervil](https://forum.realdash.net/u/Albervil)\ **Post date:** [September 16, 2026, 9:27am UTC](https://forum.realdash.net/t/canbus-problems/11106/13 "2026-09-16T09:27:59Z")
Hi, I have a very similar issue, although I connect my Android tablet directly to the MaxxECU MINI through its native USB connection, not through a CAN adapter. Could you please confirm which oil pressure sensor you are using? Is it perhaps the Hella 6PP 010 378-201 digital combined oil pressure and temperature sensor connected to a DIN input? With this Hella sensor, both values work correctly in MTune, but RealDash does not show Engine Oil Temperature and only provides “Oil Pressure (Simulated)” instead of the real sensor pressure. I previously used a Bosch combined sensor to a AIN input, and RealDash did show the oil temperature correctly. Thanks ---
**Author:** ![LarsHultman](https://forum.realdash.net/letter_avatar_proxy/v4/letter/l/a88e57/32.png) [@LarsHultman](https://forum.realdash.net/u/LarsHultman)\ **Post date:** [September 16, 2026, 10:32am UTC](https://forum.realdash.net/t/canbus-problems/11106/14 "2026-09-16T10:32:51Z")
Sorry to hear that, I use a Bosch multi sensor. It did not work for my using USB neither pressure nor temp, but now using CAN I managed to get them both to work! One of the things my tuner told me when I talked to them, was that Realdash expects bar, and maxx ecu outputs kpa. And since oil pressure is so low, a value of only a few kpa will not trigger a reading. I believe that if I tried to use gauge math x100 it would probably have worked, since the problem was that I had “0” oil pressure reading. But now since I changed input and it worked I will not mess with it and connect back. I actually have a fuel pressure sensor coming, and when I wire it I will test my thesis and connect it to the other input and see if it works with gauge math. ---
**Author:** ![realdashdev](https://forum.realdash.net/user_avatar/forum.realdash.net/realdashdev/32/6_2.png) [@realdashdev](https://forum.realdash.net/u/realdashdev)\ **Post date:** [September 16, 2026, 1:06pm UTC](https://forum.realdash.net/t/canbus-problems/11106/15 "2026-09-16T13:06:54Z")
> [@LarsHultman](#): > > Realdash expects bar, and maxx ecu outputs kpa. True. This is best solved in the CAN XML file having: ```auto units="bar" conversion="V*0.001" ``` The "V_0.001" (divide by thousand) is because kpa from MaxxECU comes from CAN bus as kpa_10.