PCM help

Sorry to hear. Starting with your Readiness Monitor
Issue...
I’d start with Datalogging, it is an intrinsically useful Dx.Tool, here. OBD2 may seem irritating, but with a decent Scantool- it’s GREAT at giving back lots of useful Dx Info. Closely monitor all recorded Sensors & observe and Document their Cycling/Corrections during a Drivecycle (in playback). Verify all these readings are within parameters. Read/verify and correct any of the below information, first.. If you don’t have a decent Scantool, with OBD2, it’s well worth it. “Decent”
is one that Datalogs Drive Cycles, allows Streaming real-time Sensor Data, Code Connect is great, descriptive Codes (Not just #’s) Actron’s are 50-250$. Many others.
It’s not “Mandatory”, but will really make life easier with MOST any OBD2 Car you need to gather Diagnostics on quickly & repair. Some can even re-Code Keys.
So- What Modifications have been made to the Car, and was the PCM running a modified Tune previously? Are you referring to readiness Monitors, only, or are there other Codes, & if so- what identical code(s) were/are both the PCM’s persistently throwing, ?
Yes, it’s POSSIBLE- not LIKELY .....You may have the previously found Codes lingering in your Scantool Software, which is why you’re seeing the same Codes, just need to be cleared- unless they are Codes that are actually still being triggered by issues- or the other Vehicle had similar issues..I’m still not 100% certain if you have readiness Issues only, or have other Codes as a result of issues present in your Powertrain, Sensors. I’ll understand better when you respond with answers, lol!
What readiness Systems are not ready, only the Catalyst Monitor affected..or others also, e.g
;. Catalyst, Heated Catalyst, Evaporative System, Secondary Air System, A/C System Refrigerant, O2 System, O2 Sensor Heater, EGR System?
When the PCM is in the ‘not ready’ status- per described, generally speaking- interpretation is the PCM’s inability to perform the test(s) required within the allotted timeline(s).
Depending on what Car modifications are present, increasing the time to allow successful completion of readiness Monitors is the fix. This specific portion cannot be done by Ford, only via an Aftermarket Tune.
Potential Causes:
1) Exhaust System modifications, including Anti-Foulers installed with O2 Sensors.
2) MAF Barometric HZ incorrectly reading high elevation, read Datalog to identify, Clean MAF or replace, if required.
3) An aftermarket Tune or error during it’s reflash, or by a Dealer’s OEM reflash error.
4) Do you have assurance the new PCU installed is running a Stock Ford Tune?
5) Battery discharge (even slightly) or Charging System anomaly, causing Voltage drop at startup. Ensure there is no anomaly, KOEO, KOER, and stability of Voltage at off Idle RPM’s (PCM information lost if Voltage drops < 12VDC). Verify 12VDC @ Computer.
6) Doors slightly left open, Door Sensors or Keys in Ignition May cause PCM to stay “awake” in many OBD2 Cars, causing issues...
7) Octane level low. Run Premium only. 93+. Tank level between 30-70% Capacity.
If Car is stock Ford should be able to reflash the PCM, after a 50 Mile Highway drive cycle @ 55-65MPH on Cruise (if equipped). It should be attempted & should be Datalogged. Was a Ford reflash to the OEM PCU offered as a solution, previously?
If above doesn't solve this, it's a probable electrical issue, slowly scan for pinched Wiring and verify Grounding points are Solid from the Battery, PCU, harness.
*FYI: Similar issue solved, found a 2012’s MAF Baro. HZ was reading 171 Hz and for area elevation 150 Hz was expected. MAF was cleaned and once relearn was performed, all Vehicle monitors went ready & it passed Inspection.
Your Key would normally not start the Car with the “Type C” ('99 to '04) RFID setup. The PATS module is integrated with the HEC (Hybrid Electronic Cluster; I.e. instrument cluster) and shares a unique security ID with the PCM that was programmed at the factory--so the HEC and PCM are "married". The car will normally not start if you swap out either without also swapping its mate.
But I’ve seen it before, some Systems are disabled, you have any issues in the Cluster or Odometer functions- which you may find if you look closer. I’d call it lucky, but if you don’t want to
get stranded someday - and will likely be under the worst possible circumstances- (Always happens like that). YES, I would get to the Dealer and kill that possibility- Dead.
They will likely want Buku verification that this is your Car, be prepared. + 60$, maybe(?).
Apologies for the long dissertation, just want to give you a decent amount of information for a head start on this. Once a few answers come my way, it should be easier to Condense.!
Until then...Cheers! John

Here's some information that may help.

ForScan ODB2 scanner w ELM327 USB
https://www.stangnet.com/mustang-forums/resources/forscan-odb2-scanner-w-elm327-usb.57/

Mond said:

2) I plugged in my 'Carmd' post install, and it read out the same errors as my previous PCM. Is that even possible? Could it just be the carmd already had the errors stored and since it's not the best tool it didn't read anything new?

Click to expand...

It might help to actually post what the DTC codes are. There are 1000's of them and they each have a story to tell.

But it seems to me that ignoring this is short sighted. Getting the same error after a "new-ish" PCM install either means:

• the ODB2 tool is giving bad test results
• the problem is external to the PCM.
• The PCM was mixed up and the original PCM was re-installed and a new PCM wasn't really installed. See Occam's Razor.
• the replacement PCM came with PATS disabled.

Turn the key on but do NOT crank. What does the Theft light do EXACTLY? Does it go out after a 3 second "prove out"? Does it blink?

wmburns said:

Here's some information that may help.

ForScan ODB2 scanner w ELM327 USB
https://www.stangnet.com/mustang-forums/resources/forscan-odb2-scanner-w-elm327-usb.57/



It might help to actually post what the DTC codes are. There are 1000's of them and they each have a story to tell.

But it seems to me that ignoring this is short sighted. Getting the same error after a PCM install either means:

• the ODB2 tool is giving bad test results
• the problem is external to the PCM.
• The PCM was mixed up and the original PCM was re-installed and a new PCM wasn't really installed. See Occam's Razor.

Click to expand...

The Irony!! I’m not the only one who uses Occam’s Razor, here.lol!

That is solid logic, WMBURNS. If the Computers did get mixed up accidentally & the Original PCM was re-installed, it certainly explains away a few things...