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      05-06-2021, 10:57 AM   #9
Major General

Drives: "NBO" 330i
Join Date: Jun 2014
Location: earth

iTrader: (0)

it's a check used so you can't buy a lower model car, and get the benefits of the higher model car with a flash of one of the stock calibrations (like, 328i to 330i).

If the parameter c_state_pow_clas_veh doesn't match what's stored in the CAS and internal memory of the DME, the engine will still run but it will run with reduced power in limp mode.

The ways around it are to change the power class in the tune to what's already inside the DME/CAS, or disable the check entirely. The 330i tune for the 328i is actually a modified stock 328i calibration, with all of the important settings copied from the 330i, but I still disable the check because it's just safer (since people often try to change it in the CAS, not realizing it won't do anything, and can actually make things worse).

This mattered more when these cars were new, a 325i was a lot cheaper than a 330i. You could have bought a 3-stage manifold and flashed the 330i tune for 1/10th of the cost difference, except people didn't know about the power class check so it ran in limp mode (there are many other differences between the two cars that make the 330i better, but most people only care about the power). People just assumed for a long time it couldn't be done.
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