RomRaider

Hi

I have an -03 JDM 350z that I've been trying to get cruise control to work with and could use some help or pointers.

I used the SH7058 CF48D binary as comparison and searched for Cruise Control Specifications Choice Flags, Cruise Control, PTD Open-Degree Operation Switching Flag and Cruise Control DTCs from the SH7055 CD415, which I think should be correct. I then modified them for the CD415 to match the CF48D, installed cruise controls for the steering wheel and cancel switch to the brake pedal, and was hit with P1564 DTC. Turns out my car was lacking cruise control wiring between M23 and M72 connectors, so I added those and the DTC disappeared.

Now is where I've hit a wall currently. I have no DTCs, the car works just as before, but cruise control still doesn't function. Looking with consult, I can see that the brake switch 1, nor any of the cruise control switches change state when they are pressed. Does anyone happen to know what flag I might still be missing that I haven't enabled or what could be the possible reason for it not working?

Are CID supmasks used only for diagnostics/obd readers or does enabling/disabling them affect the actual ECU logic as well?

I've added the supmask addresses to CD415 and comparing them to CF48D, again, the 2B Cruise control set speed & 2A Cruise Control Vehicle Speed are not active on CD415

Here's a DIY PDF I found, certainly worth checking out!
https://zcarblog.com/wp-content/uploads ... l-rev2.pdf


CID supmasks are used to tell the scan tool what's supported and what's not. They don't actually change ECU functionality.

Hi, I am working on this subject. Could be interesting to get your bin file to test a solution, I am doing it through wols. Let me know if you want to test.

Okay thanks, I was thinking that they just report what diagnostics are available and that's it, but wanted to be sure. I'm scratching my head over what flag am I missing for the cruise control.

Info similar to that pdf is what got me started on this project. The unfortunate thing is, it seems the JDM z33 never came with cruise control, so I can't simply flash a compatible rom as the US based models have done, and the SH7055 binary doesn't make this any easier either!

The rom is really odd with DTC codes as well. I've located the memory address correctly for the full DTC list, and enabling the ASCD steering switch correctly identified the open circuit I had due to missing the two wires I mentioned, but when I compare the active and inactive DTCs to the CF48D, there are some *really* unexpected DTCs inactive on mine, such as P0172...P0175 System too rich/lean bank1/2 or P0506/7 idle rpm out of spec.

A little progress! I got the steering wheel controls to react to input. Looking at Ghidra, the memory addresses 6066 & 6067 seemed to match with 82EE & 82EF based on xrefs etc. for cruise control spec flags and PTD flags respectively.

In wols, the 6067 was suspect though, because why would CD415 have any value besides 0 there when it doesn't have cruise control. So I shifted the flag addresses by one to 6065 & 6066 and the steering wheel controls are now reacting properly. Cruise control target speed is still not changing though.

What lead you to PTD Open-Degree Operation Switching Flag change?

In СD415 mSWASCD is @ 0x6066 and mSWASCD2 is @ 0x6067.
So I'd be trying mSWASCD = 0x41 and keeping mSWASCD2 = 0x09 for CD415.

Also for proper ASCD operation it worth trying SID 22 12 20 and SID 22 13 00 supmask change to allow proper tracking of ECU params via diagnostics during ASCD operation.

Moreover, respective DTC sup mask @ 0xA2B0 is worth to be changed to 0xFA.

In addition to above flags some ROMs may require extra calibration - there are certain constants that affect the torque calculation, including mTRLDFD - Flat road running resistance table. But you seem to be lucky and CD415 has it with more or less reasonable values. Most of RHD ROMs have totally random values there causing mad, almost full throttle acceleration under ASCD

P.S. Generic hint - ASCD code for CD415 is under sub_60458 and six subroutines in it. It's huge and complex, but all the magic is done there.

I was changing both cruise control flags to be identical to CF48D values. When I had mSWASCD @ 0x6066 = 073 and mSWASCD2 @ 0x6067 = 041 as in CF48D, my steering wheel cruise controls were not changing state according to input.

With mSWASCD @ 0x6065 = 073 and mSWASCD2 @ 0x6066 = 041 the steering wheel controls were changing correctly, but cruise control target speed would not change when trying to set it.

Okay, just tested mSWASCD @ 0x6066 = 041 and mSWASCD2 @ 0x6067 = 009 and the behavior is the same as when I shifted the addresses. Steering wheel controls change state and cruise light is activated according to Consult but cruise control still doesn't work and the cruise control target speed stays at 0 km/h

Another thing that concerns me, is that only Brake switch 2 switches to ON when pressing brake pedal, and even though "P1572 - ACSD BRAKE SWITCH" is enabled, I'm not getting a DTC when unplugging the sensor.
Can anyone confirm that both Brake switch 1 & 2 should change state when pressing brake pedal?