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Mode 01 • PID 09

OBD2 PID 0109

Long term fuel trim, Bank 2

Definition

Mode
01 (hex)
PID
09 (hex)
Data bytes
1
Formula
(A-128) * 100/128
Range
-100 – 99.22 %
Units
%

How to read PID 0109

Send mode 01 with PID 09 over OBD-II. The ECU returns 1 data byte(s), decoded with (A-128) * 100/128 (A, B, C, D are the returned bytes in order). The result is “Long term fuel trim, Bank 2” in %. This is standard SAE J1979 data supported by most OBD-II scan tools and loggers.

Why it matters for tuning

Live PIDs like this are how tuners and workshops verify a remap on the road — logging RPM, load, boost, lambda and temperatures to confirm the map is safe. The desktop Softechpro Solutions software complements live logging with offline ECU editing: DPF/EGR/AdBlue/DTC off and Stage tuning with automatic checksum.

Related PIDs

0105 Engine coolant tempera0106 Short term fuel trim, 0107 Long term fuel trim, B0108 Short term fuel trim, 010A Fuel pressure010B Intake manifold absolu010C Engine RPM010D Vehicle speed

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