Toyota BEANs, Multiplex etc

[keith]

Hello All,

I have been working on decoding the BEAN coming from my engine (1UZFE VVTi) for a couple of years now (on and off, a couple of hours here and there). Its while since I worked on it and since last time this thread has appeared.

I have made a small board based around an Audrino Nano and written a program to capture the data, and it mostly works. I get about a 94% successful decoding rate, I know why its not 100% and I'm not too worried about that just at the moment.

My engine is going into a boat, and at this stage the only thing I am looking to get out of the BEAN data is the water temperature, which I think I have found in the data stream. But it lead me to wonder what other useful info might be in the datastream and if any one has a list of the Destination ID's and Message Id's etc. This would save a lot of guess work.

My decoder is a work in progress, but I am quite happy to share everything I know, and my source code etc. My code doesn't check the CRC yet, I will be re-reading previous posts and adding that later once I get my head around it, but again its not critical for me just yet.

[George]

For a boat it would be better to screw non-vvt temp sensor instead of plug and forget it. Better focus on proper a/t emulation as vvti stock ECU would limit the power if both speed sensors (sp2,nco) are not reading the proper frequency

[keith]

Hi George

The BEAN thing for me has always just been for the challenge of it. Something to mess around with on quiet nights. I'm going to keep going with it since I am so close, but adding a standard sensor has always been my fallback plan.

Interesting what you say about SP2 and NCO, I hadn't come across anything saying these needed signals needed to be emulated, although most of the information out there is for the non vvti models.

Do you have any information about what sort of frequency / waveform these inputs are expecting? I'll do some searching myself, problem is most forums don't let you search on "words" as small as 3 characters, which in this case both of these signal names are.

[George]

Waveforms don't really matter as long as you keep the amplitude above 3V and limit the current at about 10mA
The trick is how the frequencies of the two signals are related to each other and to engine RPM
I think that there's still place for experiments for finding 'shortcuts'

[madmont]

Hi George
I recently swapped a 2JZGTEVVTI auto from a JZS161 into my Hilux. Wired up the up-down buttons on the steering wheel as well as the cruise control. It all worked but I was unhappy with the auto and changed back to the R151 manual box. I made a 10 slot sensor wheel for SP2 which runs at tailshaft speed and wired up the selector plug to send a D signal to the ECU . I have no NCO signal . The JZS161 instrument display shows that the shifter is in D . When I put it in reverse both R and D indicators light up . The ECU\PWR warning light flashes but the Check Engine warning no longer comes on to tell me about no speed signal . The cruise control now works as it has the SP2 signal

[George]

Do you feel like it still has full power to the wheels?

[madmont]

Feels OK..........

[George]

Very good news! And if you disconnect your SP2 signal, does it feel worse?

BTW , regarding the MPX topic, I finally figured out how to turn on the A/C for 1UZ, 3UZ, 2JZ-GE, 2JZ-GTE
Funny is that I started the research over 3 years ago
I recall that Wilbo or someone else wanted this thing but finally took the other way

[madmont]

I have not tried disconnecting it. I have the air conditioning working off the Hilux system with a rev limit set for the compressor.
Here is picture of sensor wheel and sensor

[George]

I would rather do the same in electronic way, in other words there can be different approaches to feed this signal to ECU. It's more interesting if it helps at all =)

[uvamosk]

Hello guys,
Sorry about this revival again but I'm in the same scenario as a lot of you. I'm doing a engine swap into a mr2 spyder and I am trying to bridge the gap between multiplex bean and the engine going into the car. My concerns are getting the temp gauge, alternator light to work and being able to trigger a ground path to the ECU being used In the car.

I have experience with arduino Platform and far far less knowledge than what you guys have. Currently I have built a solution for A/C function by using the direct inputs from the climate controls having them go to a PIC and then having it do the logic to control grounding the ECU pin to switch A/C on.

This works but it's not as elegant as doing one wire (mpx) to the gauge cluster and one wire (grounding through module i built) to the ECU.

I would really appreciate the help you guys could give. I want to also help proliferate the knowledge of this network and help make it more accessible to people. I just really don't know where to start If this was CAN it's a lot easier as there is a lot of stuff off the shelf to crack it and sniff it.

Thanks guys.

[bondango]

revival again

Just done a jzs161 Auto VVTI swap into a pre-facelift JZA80 supra. We have everything working as normal. However we want to use the PWR/NORM and SNOW buttons.
So we have the Bodyecu from a GS300 (same year but UK spec) and have wired the buttons to it, and going from the bodyecu1 MPX1 to ECU MPX1 but no dice on the ECU seeing the data from the bodyecu1.
We are able to link into the bosyecu1 over OBD and can see the buttons do function.
Now, regarding the MPX1 data transmission, does it have to go through any other bus components first, or should the bodyecu1 MPX1 to ECU MPX1 work??? or does the MPX data differ between markets i.e. do we need the Bodyecu1 from the JZS161??

[George]

I do have complete solution for JZS161
All MPX wires can be connected together in any order
Data encoding differs in various chassis types, but difference in markets is unlikely

[bondango]

I do have complete solution for JZS161
All MPX wires can be connected together in any order
Data encoding differs in various chassis types, but difference in markets is unlikely

Hi george, the only MPX data I need for Engine ECU is MPX1 and we only want the PWR/SNOW button, as the JZA80 does not use the multiplex system.
Even though we have the body ecu no.1 from a same year GS300 I am thinking the JZS161 uses different data encoding. Will try and see if we can track down a bodyecu no.1 from an Aristo
As we are only interested in the 2 Button data there is no point at Multiplex-DAC conversion really.

Marty

[George]

I don't do mpx-dac conversion
What I make is A/C on, idle-up, power/snow commander device that works over mpx