RomRaider

Let's get to the bottom of disabling certain features the proper way, rather than disabling all of the individual DTCs.

DTC hardware flags (on VD70A at least):

01 - HO2B1S1
02 - HO2B2S1
03 - HO2B1S2
04 - HO2B2S2
05 - Low coolant temp/Thermostat deleted
06 to 0A - Purge/Evap
0C - Catalyst monitoring
0D - Misfire
0E - A/F too lean or too rich B1
0F - A/F too lean or too rich B2

The hardware flag I want to set most commonly is 0C but once 03 and 04 would have been handy rather than disabling all of the DTCs. Also for turbo setups, converting to "single bank" as well as removing hardware flag 02 so that a single O2 sensor post-turbo could be used rather than having to put O2 sensors pre-turbo but still separated into banks which is always hard.

In the ZB060 A2L, some of these items look likely to set the 0C, 03, 04 or 02 flags:

mO2S 0x8923 "O2 sensor position" bits:
mfFO2B2 0x10 "Bank 2, sensor 1 O2/S excuse flag"
Possibly more in here that aren't documented

mOBDSW 0x892B "OBD function choice flag" bits:
mfCJST2 0x80 "It is chosen repeatedly"
mfFLEET 0x20 "FLEET experiment car"
mfFCATS 0x10 "Stage choice"
mfCATDGN 0x04 "Experiment choice"

mOSCSW 0x895F "ROM inclusion byte" bits:
mfCATCNG 0x80 "Catalyst diagnosis slice setup region switching"
mfPREDAF 0x40 "The existence of the SMC prediction A/F" - I have no idea what this means so thought I'd add it.
mfOSCBANK 0x20 "A control choice flag for the bank" - Looks like a single bank switch

mSOBSW2 0x8B17 "OBD function choice flag" bits:
mfRO2OUS 0x80 "RrO2/S response time diagnosis stage 2 diagnosis execution judgement"
mfRO2IZS 0x40 "RrO2/S Unusual voltage diagnosis stage 2 diagnosis execution judgement"

mSWDOS 0x8B50 "DOS control switching SW" bits:
mfF2IN1 0x04 "O2/S system choice"


I'm out of time for tonight but has anyone else investigated this?

Maybe these hardware groups aren't used at all but it'd be interesting to at least find out.

For now I'm moving to using the DTC supmasks rather than zeroing out the DTC options. Most tuning tools zero out the DTC options, probably just because they're easier to find. If a DTC is disabled in the supmask, does that mean the DTC option for that DTC is not used in any way?

Could the 3rd byte in DTC Descriptor entries (these "hardware flags") be an indication that all DTCs for any given hardware flag must be either enabled or disabled but not a mix?

I disabled some rear O2 faults but not all because I still want a check engine light if a cable gets shorted to ground for example BUT it did not work. See here:

viewtopic.php?f=65&t=18551