FORScan Mod List for Mazda (MX-5, CX-5, Mazda3)

This is the master reference for documented FORScan module configuration changes on Gen 6 Mazda SkyActiv vehicles: organized by category, with the module, byte address, hardware requirement, vehicle compatibility, and risk level for each.

Covered vehicles: ND MX-5 (2016–2023), CX-5 KE facelift (2016) and KF (2017–2020), Mazda3 BM (2014–2016) and BN (2017–2018). Every change here targets a body control module over OBD-II. None of it touches the CMU infotainment unit, so these changes survive firmware updates, factory resets, and battery disconnects.

Before you start

Three things are non-negotiable for any of these changes:

1. An OBD-II adapter with MS-CAN support. Every module below lives on the MS-CAN bus (125 kbit/s). A standard ELM327 reads the HS-CAN bus only and will not see these modules. See the adapter buying guide for tested hardware.
2. A complete AS-Built backup of every module you intend to write. Without it, reverting a bad value means hunting for stock data from strangers. See AS-Built backup and restore.
3. FORScan for Windows with an extended license (roughly $10–15/year). The free version reads modules but cannot write. FORScan Lite on iOS/Android has limited module access.

After editing any AS-Built data block, you must recalculate the checksum byte before writing it back. The community standard is the Mazda SkyActiv OBD-II Calc spreadsheet (SergSlimMazda). The FORScan overview covers the checksum mechanism in detail.

Risk level definitions

Level	Meaning
Low	Software-only change using existing hardware. No known failure cases. Fully reversible.
Low-Medium	Software-only but changes visible driving behavior (brake lights, DRL pattern). Fully reversible.
Medium	Requires specific hardware to be present. Enabling without the hardware causes dashboard warnings or DTCs. Reversible.
High	Touches safety-adjacent or powertrain systems. Wrong values affect driveability or safety functions. Not covered here.

1. Lighting

DRL configuration

Detail	Value
Module	FBCM (0x726)
Risk	Low-Medium
Hardware required	No (uses existing lights)
Vehicles	ND MX-5, CX-5, Mazda3

Changes which lamps act as daytime running lights. Three options:

FBCM 726-50-01 value	DRL source
01xx	Parking lights only
02xx	Parking lights + low beams
08xx	Turn signal lamps (signature DRL look)

DRL master enable is FBCM 726-01-01 B0 bit 2 = 0 (inverted logic: 0 = enabled).

EU models often ship with DRL mandatory and different baseline values. CX-5 trims with LED headlights (2017+ Touring and above) may default differently than halogen trims, and Mazda3 BN models with LED signature strips behave differently than halogen DRL.

Fog lights with high beams (bambi mode)

Detail	Value
Module	FBCM (0x726)
Risk	Low-Medium
Hardware required	Yes (fog lights installed)
Vehicles	ND MX-5, CX-5

Overrides the factory behavior of cutting the fog lights when high beams come on, keeping near-field illumination at night.

FBCM 726-01-01 packs auto headlights, auto wipers, and bambi mode into the same block; exact bit positions vary by vehicle. See the per-vehicle pages.

Headlight off timer

Detail	Value
Module	RBCM (0x7B7)
Risk	Low
Hardware required	No
Vehicles	ND MX-5, CX-5

Exposes a CMU menu option to keep the headlights on for 15–180 seconds after shutdown, triggered by pulling the high-beam stalk after the engine is off.

Address: RBCM 7B7-01-03 B1 bit 4 = 1 (timer visibility in the CMU menu).

Blinker on remote lock/unlock

Detail	Value
Module	RBCM (0x7B7)
Risk	Low
Hardware required	No
Vehicles	ND MX-5

Three blinker flashes when unlocking with the key fob.

Address: RBCM 7B7-01-01 B1 bit 1 = 1.

2. Locks and security

Auto door lock/unlock

Detail	Value
Module	RBCM (0x7B7)
Risk	Low
Hardware required	No
Vehicles	ND MX-5, CX-5, Mazda3

Locks all doors above roughly 20 km/h and unlocks at ignition off. After coding, new options appear under CMU Settings > Car > Lock (reset the page to make them show).

Block	Byte.Bit	Function
7B7-01-01	B1 b7	Master enable
7B7-01-01	B4 b6	Lock when ignition ON
7B7-01-01	B4 b3	Lock when doors open
7B7-01-02	B4 b5	CMU menu visibility
7B7-01-02	B4 b3	Display setting (0 = show)

Find My Car (horn on double-lock)

Detail	Value
Module	RBCM (0x7B7)
Risk	Low
Hardware required	No
Vehicles	ND MX-5, CX-5, Mazda3

Double-pressing the fob lock button honks the horn and flashes the hazards.

Address: RBCM 7B7-01-02 B0 bit 6 = 1.

Auto-fold mirrors on lock

Detail	Value
Module	RBCM (0x7B7)
Risk	Medium
Hardware required	Yes (power-fold mirror motors)
Vehicles	CX-5, Mazda3

Folds the mirrors automatically when locking with the fob.

The power-fold motors must physically be present. Look for a manual fold button on the driver’s door switch pack; Base and Touring trims usually lack the motors, while Grand Touring and Signature may have them depending on market. Enabling this without the hardware does nothing — no damage, no function. Fold control bits move around by model year and region; verify against the per-vehicle pages and your own AS-Built data.

3. Convenience

i-Stop default OFF

Detail	Value
Module	SSU (0x731)
Risk	Low
Hardware required	No
Vehicles	ND MX-5, CX-5, Mazda3

The most common FORScan change across the SkyActiv lineup. i-Stop defaults to OFF at every engine start; the dashboard button still toggles it on manually during a drive.

Address: SSU 731-01-01 B1 bit 4 = 0 (stock is 1).

Behaves identically on manual and automatic transmissions. The 2019+ CX-5 2.5T uses a different i-Stop implementation but the same SSU address.

Auto Hold default ON

Detail	Value
Module	EPB
Risk	Low
Hardware required	Yes (electronic parking brake)
Vehicles	CX-5 KF (2017+)

Auto Hold engages by default at each start instead of needing a button press; the button still toggles it manually.

The default bit’s position varies by model year — check your AS-Built data against community documentation. CX-5 KF only; the ND MX-5 and Mazda3 BM/BN have no electronic parking brake.

One-touch windows (all passengers)

Detail	Value
Module	RBCM (0x7B7)
Risk	Low
Hardware required	No
Vehicles	CX-5

Enables one-touch up/down for every window, not just the driver’s. Byte positions differ between KE and KF.

One-touch turn signals

Detail	Value
Module	RBCM (0x7B7)
Risk	Low
Hardware required	No
Vehicles	Mazda3

Enables the three-blink one-touch signal on trims that don’t have it from the factory. Byte positions vary by model year and region; some Mazda3 trims already ship with it.

4. Display and instrument cluster

Cruise control display type

Detail	Value
Module	IC (0x720)
Risk	Low
Hardware required	Cruise control stalk present
Vehicles	ND MX-5

Switches between standard cruise control, cruise with speed limiter (LIM), and MRCC display type.

IC 720-04-23 B4 bit	Function
b6	Cruise control with speed limiter (LIM)
b5	Standard CC / MRCC enabled
b4	No cruise control (disabled)

All ND MX-5 trims have the cruise hardware. Do not enable the MRCC display without radar hardware.

Cruise control digital display

Detail	Value
Module	IC (0x720)
Risk	Low
Hardware required	Cruise control stalk
Vehicles	ND MX-5

Address: IC 720-01-02 B1 bit 7 = 1 (digital set-speed readout for cruise control).

Dynamic camera guidelines

Detail	Value
Module	IC (0x720)
Risk	Medium
Hardware required	Yes (CAN-connected reverse camera)
Vehicles	ND MX-5

Adds steering-responsive path lines to the reverse camera view.

Address: IC 720-04-27 B2 bit 3 = 1.

Works only with a CAN-bus reverse camera. The ND MX-5 GT trim has this from the factory; Sport and Club without a CAN-connected camera won’t show path lines even with the bit set.

5. Safety

Emergency Stop Signal (ESS)

Detail	Value
Module	FBCM (0x726)
Risk	Low-Medium
Hardware required	No (uses existing hazard lights)
Vehicles	ND MX-5, CX-5, Mazda3

Rapid hazard flashing under hard braking above roughly 60 km/h (37 mph) to warn following traffic of sudden deceleration. Standard on many European cars, not factory-enabled on most USDM Mazdas.

Block	Byte.Bit	Value
726-01-02	B0 b1	1
726-01-02	B1 b0	1
726-01-02	B3 b1	1

All three bits are required. Uses existing hazard hardware (no wiring or parts) and works on every trim of all three vehicles.

Vehicle compatibility matrix

Mod	Module	ND MX-5	CX-5	Mazda3	Hardware?	Risk
i-Stop default OFF	SSU	Yes	Yes	Yes	No	Low
Auto door lock/unlock	RBCM	Yes	Yes	Yes	No	Low
Find My Car	RBCM	Yes	Yes	Yes	No	Low
ESS	FBCM	Yes	Yes	Yes	No	Low-Medium
DRL configuration	FBCM	Yes	Yes	Yes	No	Low-Medium
Headlight off timer	RBCM	Yes	Yes	No	No	Low
Fog with high beams	FBCM	Yes	Yes	No	Fog lights	Low-Medium
Auto-fold mirrors	RBCM	No	Yes	Yes	Power-fold	Medium
Auto Hold default ON	EPB	No	KF only	No	EPB	Low
One-touch windows	RBCM	No	Yes	No	No	Low
One-touch turn signals	RBCM	No	No	Yes	No	Low
Blinker on lock/unlock	RBCM	Yes	No	No	No	Low
CC display type	IC	Yes	No	No	CC stalk	Low
CC digital display	IC	Yes	No	No	CC stalk	Low
Dynamic camera lines	IC	Yes	No	No	CAN camera	Medium

Module address quick reference

All three vehicles use the same module addresses:

Module	Address	Primary functions
RBCM	0x7B7	Door locks, lighting timers, Find My Car, mirrors, trunk
FBCM	0x726	DRL, headlights, wipers, fog lights, ESS
SSU	0x731	i-Stop, keyless entry, immobilizer
IC	0x720	Gauge cluster, ADAS display, camera, cruise control
EPB	Varies	Auto Hold (CX-5 KF only)
PCM	0x7E0	Powertrain (do not modify without expertise)

These all sit on the MS-CAN bus (125 kbit/s). Switch your adapter to MS-CAN mode before scanning or they won’t appear.

What not to modify

These modules can create unsafe conditions if written incorrectly, and none of them are covered here:

Module	Risk	Why
PCM (0x7E0)	High	Engine behavior, fuel maps, speed limiter. Wrong values affect driveability.
ABS/DSC	High	Braking behavior and stability control.
SRS (airbag)	High	Airbag deployment. Bad config can prevent or falsely trigger deployment.
EPS (steering)	High	Electric power steering assist.

Enabling ADAS display features (LDWS, HBC, SCBS, BSM, MRCC) in the IC module without the matching sensor hardware throws persistent dashboard warnings and DTCs. Confirm your trim has the physical sensors before setting any ADAS bit.

Frequently asked questions

Will FORScan changes survive a CMU firmware update?

Yes. These changes live in body control modules (RBCM, FBCM, SSU, IC), which are entirely separate from the CMU infotainment unit. Firmware updates, factory resets, and battery disconnects don’t touch them.

Can I brick my car with FORScan?

The body-module changes listed here (locks, DRL, i-Stop, ESS) are all reversible by writing the original values back. The real risk is in the safety-critical modules (PCM, ABS, SRS, EPS), which this guide deliberately leaves out. Back up every module before you write to it.

Do I need the extended FORScan license?

For writing, yes. The free version reads module data, useful for backups and inspection, but cannot write modified AS-Built values. The extended license runs about $10–15 per year.

Are these changes detectable by a dealer?

A dealer with FORScan or Mazda IDS could read your AS-Built data and compare it to factory values. In practice they rarely inspect AS-Built data unless diagnosing a complaint tied to a modified module. Restoring your backup before a visit removes any trace.

Do the same addresses work across all three vehicles?

Module addresses (RBCM 0x7B7, FBCM 0x726, SSU 0x731, IC 0x720) are identical across these SkyActiv vehicles. Byte layouts are largely the same, but baseline values differ by vehicle, trim, model year, and region. Always verify against your own AS-Built backup.

References

• FORScan overview — adapters, backups, checksums, safety boundaries
• Adapter buying guide — tested OBD-II adapters with MS-CAN support
• AS-Built backup and restore — backup procedure before any changes
• ND MX-5 FORScan configuration — full address tables and step-by-step guides
• CX-5 FORScan tweaks — CX-5-specific caveats and KE vs KF differences
• Mazda3 FORScan tweaks — BM/BN module differences and regional notes
• FORScan software — official download
• Mazda3Revolution ASBuilt thread — 300+ page community resource covering all SkyActiv vehicles
• OHP Tools video guide — checksum spreadsheet walkthrough
• OHP Tools AS-Built data list — community-maintained mod list