A report for the mechanic when the fault is intermittent
«Everything is fine here» is the most annoying phrase. A trip recording ends it.
Start recording before the trip
The app writes the readings to a file. Start early: a fault that happens once a week will not wait for you to press a button.
Repeat the conditions the fault happens in
Cold start, acceleration, a long climb, standing in traffic — whatever it usually follows. The freeze frame of an earlier code hints at what to repeat.
Note the moment you felt it
A jerk, a flat spot, an odd noise — remember the minute. The recording then shows what the RPM and the trims were doing at that second.
Build the report
The report contains the codes found with their explanations, the readiness monitors and the highest and lowest values of the trip. It is plain text — send it to the mechanic in advance.
Do not clear the codes before the visit
A cleared code takes its freeze frame with it and resets the monitors. The mechanic will have to wait for it all to happen again — and you will pay for that wait.