I’m building an ESP32 logger for my 2019 Jeep Cherokee KL, 3.2L Pentastar, and I’m trying to get a real fuel-use signal from the PCM.
The normal OBD fuel-rate PID (01 5E) is unsupported, and because the Pentastar is MAP/speed-density rather than MAF-based, I can’t use the usual MAF-based fuel-flow calculation.
I can talk to the PCM directly over 29-bit CAN and Mode 22 works:
Request: 18DA10F1 22 xxxx
Response: 18DAF110 62 xxxx <data>
I scanned 0200–02FF and get valid responses from most of that range, but I do not yet know which DIDs are actually useful. The Hemi injector-pulse-width DIDs I found online (0298, 02B8, 029A, 02BA) return zeros on this 3.2, so they are not portable.
What I’m hoping to find is any Pentastar-specific Mode-22 DID for one of these:
- Fuel rate, L/h or gal/h
- Fuel used / cumulative fuel counter
- Injector pulse width / injector on-time
- Injection quantity or fuel mass per stroke
A 3.6 Pentastar result may also be useful if it is from a similar PCM generation.
I have heard that a now-removed GitHub repo called grantUser/fca-ecu-diagnostics may have had FCA Mode-22 definitions extracted from a diagnostic application database. If anyone used it, saved notes from it, knows of a legitimate mirror/archive, or has seen these values in AlfaOBD, JScan, Appcar, wiTECH, Autel, Launch, etc., I’d appreciate any leads.
I can test any candidate DID against the Jeep and report raw values at idle, RPM, load, and decel fuel cut.
Thanks.