POLDIAG Mercedes - a set for working with car keys, latches, Mercedes control units, used for adding and complete loss (AKL). Additional licenses can be opened (MQB and BCM2).
The main advantage of the device is the absence of tokens, limits, and mandatory subscriptions.
Main functions of Poldiag MB
- programming all Mercedes keys up to the FBS4 system (up to an average of?2014), including in case of complete loss (AKL)
- reading passwords and data via OBD2 or infrared adapter (IR)
- resetting and binding used keys, locks, transmission control units, engine control units
- full reading of EZS information without the need for disassembly
- resetting all types of FBS3 engine control units
- working in key emulator mode
Main advantages of the device compared to analogs:
- calculating passwords without tokens, unlimited per day (including in case of complete loss)
- absence of mandatory subscription that needs to be paid every year
- possibility of opening additional licenses, such as MQB or BCM2
- support for all types of keys (original: MOTOROLA, NEC, BGA; analogs: BE, VVDI, CGDI)
- fast online password calculation
Additional licenses, including MQB or BCM2, can be opened for the POLDIAG Mercedes device.
Package includes:
- Main Poldiag unit
- OBD2 cable
- power adapter (which supports VAG BENCH MEDC17)
- NEC adapter for key resetting
- IR adapter
- IR adapter for key writing and reading
- Mercedes license
Important:
This function is available only on certain BMW engines and is NOT applicable to other vehicle brands.
The information below applies only to stock engines with factory ECU software and a standard exhaust system.
What This Parameter Actually Represents
This is NOT a direct measurement of fuel octane and is NOT a direct octane reading calculated by the ECU.
The value is an adaptation factor ranging from 0 to 1, where:
- 0 = no correction
- 1 = maximum correction
According to BMW’s internal definition:
Faktor adaptierte Kraftstoffqualität (0 = ROZ98 / 1.0 = ROZ91)
- 0 corresponds to 98 ROZ
- 1.0 corresponds to 91 ROZ
ROZ is the German equivalent of RON (Research Octane Number).
The device converts this multiplier into a more intuitive octane value for user convenience.
⚠️ The device does not measure anything itself.
It only displays the data provided by the engine control unit (ECU).
How the ECU Evaluates Fuel Quality
Each ECU has different calibration sensitivity:
- Sensitivity to the adaptation factor
- Sensitivity of the knock control system
Fuel quality is evaluated subjectively by the ECU, primarily based on:
- Knock ignition timing corrections
- Overall engine noise levels
BMW G-Series & LCI F-Series (B-Engines)
B38 / N63 / S63 / N74
These engines are highly sensitive to octane adaptation.
- During warm-up and cruising, the displayed octane may frequently drop to 95 or lower.
- This does NOT automatically indicate poor fuel quality.
- Under load, the value should increase.
⚠️ If the value continues to decrease under load, this may indicate a problem.
B46 / B48 / B58
These engines have low sensitivity.
- During cruising, octane will typically display maximum values even with mediocre fuel.
- Under load, the value will decrease if fuel quality is truly poor.
S58
Octane correction is virtually inactive.
- It will typically always show 98.
- If it drops below 98, fuel quality is genuinely very poor.
BMW F-Series (Pre-LCI) with N/S Engines
Most pre-LCI F-series ECUs do not calculate octane adaptation.
Do not expect this parameter to function.
S55
- Octane parameter not used by the system
- Display not supported
- However, display of the last 5 refueling quality events is supported
S63
- Octane parameter not used
- Display not supported
- Refueling quality display not supported
BMW E-Series
Octane parameter not available. Display not supported.
Important Notes About Tuned Vehicles
With modified hardware or custom tuning, behavior may vary significantly. Always consult your tuner regarding expected operation.
Key principles:
- If octane drops under load, it means fuel quality is worse than expected under those conditions.
- This does NOT automatically mean the fuel itself is bad.
Examples:
- If a tuner increases ignition timing and boost pressure, even good fuel may cause knock corrections, and the ECU may interpret it as poor fuel.
- Thin-walled or poorly mounted exhaust systems may create parasitic noise, which the ECU may interpret as engine knock, causing negative correction.
- Conversely, if knock sensitivity is reduced or octane correction is disabled in tuning, readings may appear ideal while actual engine safety is compromised.