CAN bus to CCD bus Protocol Translator(Chrysler PCM Simulator)

[Alexia]

Originally Posted by xeroOTG

So I've been reading datasheets for the MCP2551 and the SN65HVD230, both look like they are capable of providing a physical interface capable of receiving on a CCD bus. When I look at the architecture diagram of the Intersil CPD68HC68S1, the CAN differential receiver implements similar function, minus arbitration detection, collision detection and idle detection. Outside of your published code, have you attempted to monitor the RxD pin while transmitting? I have a SN65HVD230 coming snail mail, so I cannot test this theory for myself.

I think the function of the Intersil could be implemented in software, bringing duplex communication into your project. Arbitration detection, collision detection and idle detection all are well documented in the CPD68HC68S1 datasheet, I just don't think I am up to the task of implementing them.

The receive pin just shows a reflection of whatever is being transmitted currently. Outside of that it never shows anything even when something else on the bus is transmitting.

[cjlagos]

Awesome! Just awesome, really impressive and thanks for sharing! I've been working on an LSx swap into my 01 XJ and this is exactly what I want to do. Only difference is I am using the GM red/blue 411 PCM which uses J1850 instead of CAN. I originally planned to drive stock Instrument Cluster by retaining Jeep PCM and using discrete sensor inputs for oil pressure, coolant temp and speedometer. Also have the Novak Tachometer module to generate CPS signal on Jeep computer. For Cruise and Check Engine Lights I used little 194 Bulb sockets with pigtails and control them separately. All of this works decently enough and works like factory, but ends up being a lot of extra wiring and complexity. Your post gives me enough confidence to scrap all of that and just move forward with an integrated solution.

I got up and running with your code on the Teensy and Waveshare CAN quickly enough - couple of observations and questions for you?

1) Airbag light stays on, looks like code is setup to turn on/off but I don't see any changes in the status light. I am keeping the Airbag module but was testing on the bench.

2) Speedometer is working but I don't see Trip or Odometer incrementing. I saw you mention your code supported this but didn't see anything? Can you describe a little bit how this works? I would have expected the IC to increment odometer itself just based on speed inputs.

3) Looks like logic for 4 smaller gauges only updates if values change? I suppose in real world these would always be changing, but on the bench it seems these messages only get sent the very 1st time. Unless the IC is powered up before Teensy, it will miss the initial messages and never update the gauges. Makes me curious how factory PCM handles this, do you think it uses CCD BUS Ack's to know if messages were properly received or not? Perhaps, sending these messages periodically even if they aren't updated would help with prototyping?

4) I tried an MCP2551 CAN Transceiver @ 5v. Seemed to work just fine, instrument panel output was the same. Any particular preference to the 3.3 Waveshare module you are using?


Thanks!

CJ

[cjlagos]

Wanted to share some info that might be useful for others working on the power train wiring. Eliminating the factory ECU does present some other challenges with regard to integrating a different control module with the rest of the vehicle. Hope you don't mind this in your thread Alexia!

I searched a long time to find Factory PCM Plugs. What I really wanted was a male version so I could make a "plug and play" harness that doesn't modify the vehicle body / chassis harness. In the end, you can get replacement female plugs from Mopar but they are a bit pricey, around $30/ea if I recall. You can see part numbers in pic below. I never did find any male versions, short of people who hacked an old JTEC PCM to steal the connector. It doesn't look like a very clean or sustainable solution so I scratched that idea.

The connectors are/were manufactured by TE under the "Super Seal" line. I was able to locate the factory style 32-pin connectors, but none have the correct "keying" to match the factory connectors - I guess these were made specifically for and only supplied to Chrysler. It makes me wonder though, after seeing the link in this thread to other PCMs that look to have same form factor & connectors. If you cut/grind the keys off, this will technically work in the factory PCM:
http://www.mouser.com/ProductDetail/...y/4-1437287-7/

Then, I found a "newer" version of the Super Seal connector, in 26 and 34 positions. Both male/female versions are readily available. I see these commonly used in other PCM applications. Holley is using these on their Dominator EFI system and you can buy some pre-made harnesses from them:
http://www.mouser.com/ProductDetail/...ity/6437288-1/
http://www.mouser.com/ProductDetail/...1-4-1437290-0/
https://www.holley.com/products/fuel.../parts/558-408
https://www.holley.com/products/fuel.../parts/558-403

The big win though, is that the crimp connectors, the pins inside these connectors are all the same. So, de-pin the factory PCM plug that is part of the body harness. Then, can simply plug those wires into a new Super Seal connector and integrate/build from there with no modification to vehicle wiring.

That Gray C3 PCM connector contains a lot of valuable signal wires. It has the input for cruise control, trigger wires for the relays in factory fuse box like fuel pump and electric fan, connection to the factory CCD bus, brake sensor wiring, etc, etc. I see a lot of people hack up the fuse box, but you can integrate @ C3 and not cut any wires at all.

C107 contains the +12v and chassis grounds to power up "the black box".

Hth,

CJ

[Jeep Driver]

Interesting thread.

[Alexia]

Originally Posted by cjlagos

1) Airbag light stays on, looks like code is setup to turn on/off but I don't see any changes in the status light. I am keeping the Airbag module but was testing on the bench.

1997 clusters need the code sent once at start up to turn it off. 1998-2001 clusters need it periodically sent to keep it turned off. If you have the air bag system in place just keep the air bag module wired into the CCD bus and it will take care of it for you.

Originally Posted by cjlagos

2) Speedometer is working but I don't see Trip or Odometer incrementing. I saw you mention your code supported this but didn't see anything? Can you describe a little bit how this works? I would have expected the IC to increment odometer itself just based on speed inputs.

Odometer is incremented by it listening to the DIST_INCR_ID (0x84) code. So the microcontroller has to calculate the distance traveled since the last transmission based on speed and time then send it using 0x84.

Originally Posted by cjlagos

3) Looks like logic for 4 smaller gauges only updates if values change? I suppose in real world these would always be changing, but on the bench it seems these messages only get sent the very 1st time. Unless the IC is powered up before Teensy, it will miss the initial messages and never update the gauges. Makes me curious how factory PCM handles this, do you think it uses CCD BUS Ack's to know if messages were properly received or not? Perhaps, sending these messages periodically even if they aren't updated would help with prototyping?

Correct, they update if a new value is transmitted. The speedometer and tachometer will fall back to zero if a new value is not sent every few seconds.

In the stock setup the CCD bus is powered and initialized by the gauge cluster. The PCM will not transmit until it sees voltage on the lines.

The logic I built into the CAN-CDD bus library so far only sends new values for those four gauges when they change or a certain timeout in seconds occurs.(I forget how long that is at the moment.)

Originally Posted by cjlagos

4) I tried an MCP2551 CAN Transceiver @ 5v. Seemed to work just fine, instrument panel output was the same. Any particular preference to the 3.3 Waveshare module you are using?

It was cheap and already soldered to a board so I could get right to prototyping.

[Alexia]

Originally Posted by cjlagos

I searched a long time to find Factory PCM Plugs. What I really wanted was a male version so I could make a "plug and play" harness that doesn't modify the vehicle body / chassis harness. In the end, you can get replacement female plugs from Mopar but they are a bit pricey, around $30/ea if I recall. You can see part numbers in pic below. I never did find any male versions, short of people who hacked an old JTEC PCM to steal the connector. It doesn't look like a very clean or sustainable solution so I scratched that idea.

The connectors are/were manufactured by TE under the "Super Seal" line. I was able to locate the factory style 32-pin connectors, but none have the correct "keying" to match the factory connectors - I guess these were made specifically for and only supplied to Chrysler. It makes me wonder though, after seeing the link in this thread to other PCMs that look to have same form factor & connectors. If you cut/grind the keys off, this will technically work in the factory PCM:
http://www.mouser.com/ProductDetail/...y/4-1437287-7/

Then, I found a "newer" version of the Super Seal connector, in 26 and 34 positions. Both male/female versions are readily available. I see these commonly used in other PCM applications. Holley is using these on their Dominator EFI system and you can buy some pre-made harnesses from them:
http://www.mouser.com/ProductDetail/...ity/6437288-1/
http://www.mouser.com/ProductDetail/...1-4-1437290-0/
https://www.holley.com/products/fuel.../parts/558-408
https://www.holley.com/products/fuel.../parts/558-403

As far as I know the connectors specific to the JTEC controllers may not be made to be in stock all the time anymore, but can be special bulk ordered in many thousands. I found this out when trying to find some of the AMP branded(Tyco/TE owned) connectors with specific keying for some of the sensors. The other road block is that many of the available product drawings have been digitally redrawn by TE from the original hand drawn AMP documents losing a lot of the original information such as part numbers.

[Cummins90]

[QUOTE=Cummins90;246417065]

This is the ecm connector cleaned up.



Nothing too complicated just meticulous.

The extension harness wasn't too hard to make with a spare had ecm. No connection issues as of yet. I had thought of taping off the ecm side and pouring a soft potting material into the wires to set them in place.

[cjlagos]

Originally Posted by Alexia

Odometer is incremented by it listening to the DIST_INCR_ID (0x84) code. So the microcontroller has to calculate the distance traveled since the last transmission based on speed and time then send it using 0x84.

Thanks, do you have any updated code that increments DIST_INCR_ID?

What IDE you are using? Having to workaround some issues with #include.

Also wanted to let you know I tried using an Intersil CDP68HC68S1E chip instead of the CAN transceiver and it worked as well!


CJ

[Alexia]

Originally Posted by cjlagos

Thanks, do you have any updated code that increments DIST_INCR_ID?

What IDE you are using? Having to workaround some issues with #include

I have a work in progress Haltech branch on my laptop. Right now I am blocked on the overall MJ project due to needing the mounting bolt for the knock sensor; which is on the way.

I am just using a text editor, TextMate, to edit the code. However, I have started using Visual Studio Code lately for C# work.

[Alexia]

I originally had a DAC in this design to send an analog TPS signal to the transmission controller. Which also included a logic level converter for the 3.3v to 5v conversion. I had a power supply and a LLC light on fire so I said, "Screw it, I will build my own transmission controller that uses CAN bus."

After a lot of frustration and lighting a few wires on fire the prototype is assembled. It passes all tests on the work bench so now I just have to test it in vehicle.

[gradon]

Keep it up!


Sent from my iPhone using Tapatalk

[mk3018]

Hi,
I have a XJ gauge cluster ,want connect to my car ECU(Delphi MT20U) with MCU.
When cluster turn on alone,it send some data and repeat about 1sec.
0x3A,0x22,0x10,0x6C;
0xDA,0x20,0x10;
0xFE,0xD2,0xD0;
0x23,0x5A,0x0F,0x8C;
What does that mean?


Thanks!

[SATURN5]

Following...

[Alexia]

Originally Posted by SATURN5

Following...

I am looking into potentially making this a retail product for people to buy. Something cheaper than aftermarket gauge setups that retains more functionality would be useful to people doing engine swaps.

[Boostwerks.com]

Originally Posted by Alexia

I am looking into potentially making this a retail product for people to buy. Something cheaper than aftermarket gauge setups that retains more functionality would be useful to people doing engine swaps.

Yes plz.