Can you read the PCM and not tune it?

[TurboJeep]

I have a 2018 Trackhawk. I kept my MPV1 from my Charger HC after I got rid of it. I know the PCM has to be hacked to tune it. Does it need to be hacked just to do some bone stock datalogs? My TH goes pig rich at 5K rpms stock. I want to see if it's Cat Overtemp that's doing it. Thanks in advance.....

[TurboJeep]

Never mind.... just saw I need a MPV2 now. SMH...

[Homer]

VCM scanner can be used on any supported vehicle and the PCM does not require modification to do so but you still need the smart access cable to make the front OBD port functional.

[TurboJeep]

VCM scanner can be used on any supported vehicle and the PCM does not require modification to do so but you still need the smart access cable to make the front OBD port functional.

Thank you

[TurboJeep]

Well I tried it anyways and it was able to log everything. I didn't need the jumper cable to just log it. Thanks anyways. Appreciate the info.

[rich24v]

Did you manage to also pull the tune without the bypass cable ?

[Homer]

Did you manage to also pull the tune without the bypass cable ?

I wonder about this too because I was able to read my buddies 2018 Challenger SXT BCM, PCM and ABS modules with AlfaOBD and no bypass...but never tried it with HP tuners. It must be for write only otherwise how do automotive shops use scan tools to diagnose problems?

[spoolboy]

You can't read the calibrations from 2018+ without the smart access cable or some other means of getting around the security.

[Homer]

You can't read the calibrations from 2018+ without the smart access cable or some other means of getting around the security.

It is curious that the security only protects accessing the PCM calibration yet I can read the configuration of BCM without a bypass. It's all dark magic to me.

[rich24v]

I had to install the bypass loom to pull the tune from 2018 rhd trackhawk.

I can read all the pids for data logging without bypass loom(afaik from the short test drive).

I now have a new unlocked pcm with the tune loaded onto it from hptuners.
couple of questions:- (excuse my ignorance here please)

1. Should I swap to the new pcm, read and license the tune from new pcm as first step ? Is the pcm an exact duplicate of original ?

2. Is it safe to assume I can re-instate original pcm and all will be as factory, ie as if nothing had ever been changed ?

3. Where does the trans tune actually reside ? in the pcm or another dedicated trans pcm ?

4. If a change is made to the trans tune, then later return that to stock, is there a record of that write made somewhere ?

5. For actual tuning, are the stock wideband data useable, or is it recomended to install a stand alone WB ?

Thanks in advance.
Regards.

[Homer]

You do know that if you ever ran the trackhawk with an aftermarket calibration it is recorded by other modules like the BCM. I don't see the P1400 that folks say shows up when you swap PCMs but my BCM does state aftermarket calibration: default...or something like that. FWIW Spoolboy had the same show up on his BCM read but only wrote to the TCM and this does not show up on bone stock vehicles.

[rich24v]

You do know that if you ever ran the trackhawk with an aftermarket calibration it is recorded by other modules like the BCM. I don't see the P1400 that folks say shows up when you swap PCMs but my BCM does state aftermarket calibration: default...or something like that. FWIW Spoolboy had the same show up on his BCM read but only wrote to the TCM and this does not show up on bone stock vehicles.

It did cross my mind a little, thanks for confirming , perhaps that particular upgrade will mature on the shelf, whilst warranty erodes..........or I can't stand the temptation.