ScottyMacSD
Member
I wanted to share the following PDF file, in hope others find it as useful as i have. Feedback is welcome, just be polite if you found and are pointing out any errors.
I've been deep in a diagnostic rabbit hole on my 6.2L for the past couple of months, and one thing that kept slowing me down was not knowing what "normal" looked like for a given PID. Plenty of places tell you which parameters to log. Almost none tell you what the numbers should actually read, or what it means when they don't.
So I asked Claude desktop app that is using an app I had it build, to put this together from Ford's own Powertrain Control/Emissions Diagnosis manual — the Typical Diagnostic Reference Values charts in Section 6, plus specs pulled from the individual pinpoint tests.
What's in it:
Altitude note: Ford's published values were taken around 620 ft. If you're running at elevation, expect MAF, LOAD, and MAP to read proportionally lower.
Corrections welcome — if your truck reads differently or you've got better numbers for something, say so and I'll update it.
I've been deep in a diagnostic rabbit hole on my 6.2L for the past couple of months, and one thing that kept slowing me down was not knowing what "normal" looked like for a given PID. Plenty of places tell you which parameters to log. Almost none tell you what the numbers should actually read, or what it means when they don't.
So I asked Claude desktop app that is using an app I had it build, to put this together from Ford's own Powertrain Control/Emissions Diagnosis manual — the Typical Diagnostic Reference Values charts in Section 6, plus specs pulled from the individual pinpoint tests.
What's in it:
- Normal ranges and failure indicators for fuel trim, O2 sensors, air and load, throttle control, fuel system, EVAP, engine operation, and electrical
- How to read fuel trim patterns to separate a vacuum leak from a fuel delivery problem from a MAF issue
- Mode 6 test IDs with their actual pass/fail thresholds, so you get measured numbers instead of guessing at codes
- An acronym table, because the PID names are not obvious
- A few things that cost me time: the 6.2L has no FRP sensor (that's direct-injection hardware — ours uses FRPT), there's no BARO sensor either (the PCM infers it from MAF and ambient temp), and measuring VREF with the sensor unplugged will read a perfect 5V through a badly corroded terminal
Altitude note: Ford's published values were taken around 620 ft. If you're running at elevation, expect MAF, LOAD, and MAP to read proportionally lower.
Corrections welcome — if your truck reads differently or you've got better numbers for something, say so and I'll update it.