Switchable Maps Tuning Guide
MG Flasher Switchable Maps – QuickStart Tuning Guide
Make sure to have the Custom Base Map imported into the project to use as a base to the tune.
Please read the Custom Tuners - Map Pack Guide for Custom Code for more information on Custom Code features
4 Steps When Tuning Switchable Maps
Step 1 — Enable the Slots You Want
MG Flasher supports 5 slots total:
Slot 0 = Base (OEM/main area) always enabled
Slots 1–4 = Custom switchable maps (enabled via switches)
Enable only the slots you plan to use:
CW_MapSwitch_Slot1___MGF_CC = 1
CW_MapSwitch_Slot2___MGF_CC = 1
CW_MapSwitch_Slot3___MGF_CC = 1
CW_MapSwitch_Slot4___MGF_CC = 1
✅ You do NOT need all slots enabled
✅ Each slot is independent
Step 2 — Enable Which Maps Will Switch
Now decide what maps actually change between slots.
These are the map-level codewords
Set to 1 for anything you want to be switchable.
Example:
Boost target → ON
Ignition timing → ON
Burble → ON
Torque limiters → ON
CW_MapSwitch_BMWtchctr_p_DifCrtnPp_M___MGF_CC = 1
CW_MapSwitch_BMWtchctr_pct_WgBasc_M___MGF_CC = 1
CW_MapSwitch_BMWtchctr_pwr_Dp_M___MGF_CC = 1
CW_MapSwitch_BMWtchctr_pwr_Pctl_M___MGF_CC = 1
CW_MapSwitch_BMWtchsp_p_ReqMax_C___MGF_CC = 1
CW_MapSwitch_BMWtchsp_rat_p_CmprMax_M___MGF_CC = 1
CW_MapSwitch_BMWtchsp_rat_p_CmprPmp_T___MGF_CC = 1
CW_MapSwitch_BMWtqe_tqc_FlApplBol_T___MGF_CC = 1
CW_MapSwitch_BMWtqe_tqc_FlApplStgNorm_T___MGF_CC = 1
CW_MapSwitch_BMWtqe_tqc_FlApplStgPwr1_T___MGF_CC = 1
CW_MapSwitch_BMWtqe_tqc_FlApplStgPwr2_T___MGF_CC = 1
CW_MapSwitch_BMWtqe_tqc_FlApplStgPwrHi_T___MGF_CC = 1
And More...
The Map Switches enable switching the given map in ALL slots. This means that if a Map Switch is enabled for a given map, then you must verify that the contents of the map in each Slot is correct.
Critical Rule:
If a map’s switch is OFF → it will NOT change between slots, it will instead take reference from the calibration in the Slot 0/OEM/Main Area
Step 3 — Calibrate Each Slot
Slot 0 → Maps are defined in OEM/Main area
Slots 1–4 → Maps are defined in Custom Area
You only need to modify the maps that are enabled in Step 2 in the slots that are enabled in Step 1
Checklist Before Flashing
Step 4 — Proceed to Flashing
The user will need to proceed to flashing the BIN from the Custom Tune area, after uploading it.
During flashing, the user will need to enable the Switchable Maps option in the Custom Options menu.
In App Map Validation
MG Flasher has a built in Map Validation tool for Custom Tunes. It is able to verify and ensure maps contain valid data, and helps keep track which codewords are enabled. Please review the feature here: Map Validity Check Tool (In-App)
It is always best to review the BIN file first, and then refer to the in app Validity check as a next step
In Depth Information (Advanced)
In general, when tuning switchable maps, there are four main parts:
Overall switch/codeword
Slot switches/codewords
Specific Map switches/codewords
Specific Map calibrations
These are the steps that should be followed when tuning using Switchable Maps:
The overall switch/codeword:
CW_OctaneSwitch___MGF_CC
Does not need to be modified. The value of the map is always overwritten in app at the time of flashing. If the “Switchable Maps” option is enabled in the custom options menu, this codeword is set to 1, otherwise it is always set to 0. Please ensure the user always marks this custom option in app when using a Switchable Maps tune
The slot switches
CW_MapSwitch_Slot1___MGF_CCetc. need to be enabled according to which slots you want active. These codewords are not enabled in app, and must be enabled in the BIN file. Each slot is independent, so you only need to enable the slots you intend to use.
The specific map switches need to be enabled according to which maps you want switched when switching slots. Enabling the maps to switch will allow them to be switched in each slot. These codewords are not enabled in app, and must be enabled in the BIN file.
The specific map calibrations must then be adjusted for each map slot according to the calibration you want to switch to.
Our Switchable maps contain 5 slots. Slot 0 is the base/default slot which is defined in the OEM calibration "main area". Slots 1-4 are defined in the custom code area.
In the screenshot below, all maps that can be adjusted to be switched using switchable maps are highlighted in purple. In this example, only Slot 1 is shown, however the same structure is found in the remaining slots.
The maps are organized in folders, grouped by their function.
IMPORTANT TO NOTE: Only the maps that have their corresponding Code word enabled in the codeword switch section above will work when switching maps. You need to make sure the data in the maps which are enabled is correct. The maps which are disabled will not be used, so the data does not need to be altered.
When preparing a custom tune that uses Switchable Maps, it is always best to download and use a CBM as the base/reference file for the tune. In doing so, the maps related to custom code are all populated with Stock data, allowing for clean reference and easy adjustability.