How to Read BMW Part Numbers on E46 E39 and E38 Comfort Modules

BMW’s OEM part number system follows a consistent 11-digit structure, but the comfort module family across the E38, E39 and E46 platforms shows exactly why understanding that structure matters before ordering a used unit. Two numbers separated by a single suffix letter can describe modules with different hardware, different software compatibility requirements and different coding needs — and fitting the wrong one wastes time and money. This guide decodes how the numbering works on this specific module family.

How the BMW 11-Digit Part Number Is Structured

Every genuine BMW electronic module carries a part number in the format: 61 35 X XXX XXX, broken into three groups separated by spaces.

Group 1 — System code (2 digits): Identifies the main system. Comfort and body electronics modules almost always begin with 61. Lighting control modules share this prefix. Drivetrain ECUs start with 12, ABS and DSC units with 34.
Group 2 — Sub-group code (2 digits): Narrows the function within that system. For comfort modules, 35 is the dominant sub-group across E38, E39 and E46 production years.
Group 3 — Component identifier (7 digits): The core identity of the exact part. The first three digits in this group broadly identify the component family; the following four are a sequential revision or variant code.

After the seven-digit group, BMW appends a two-letter hardware and software suffix that does not always appear in catalogues but is present on the label attached to the module itself. This suffix is the most dangerous part to overlook when sourcing a used unit.

Example Numbers on E38, E39 and E46 Comfort Modules

Part Number	Приложение	Notes
61 35 6 901 910	BMW E46 saloon/touring comfort module (GM5)	Base variant, non-folding mirror markets
61 35 6 901 911	BMW E46 with folding mirrors	Last digit increments — different software state
61 35 6 924 786	BMW E46 coupe/convertible comfort module	Coupe body CAN address differs from saloon
61 35 8 368 784	BMW E39 5-Series comfort module (GM3)	Fits most E39 saloon from 1996–2003
61 35 8 375 500	BMW E38 7-Series comfort module (GM1)	Memory seat and mirror variant
61 35 8 375 501	BMW E38 7-Series without memory	Hardware-identical to 500 but different EEPROM

The difference between 910 and 911 in the E46 column is a single digit. On the bench the modules look identical. Fitted to the wrong car, the folding mirror function does not initialise and the GM5 may set an internal fault for an unexpected equipment configuration. More critically, when a replacement is coded with INPA or PA-Soft, the software version embedded in the module must match the body variant stored in the vehicle order — coding alone cannot change the hardware capability. For comparison, see Кои модули дели BMW E53 X5 с E39 и E46.

What the Suffix Letters Tell You

Stamped or printed directly on the module’s label beneath the main number, the two-letter suffix follows a standard BMW convention:

First letter — hardware index: Changes when the PCB, connector or internal component changes in a way that is not backward compatible. A module stamped -C will generally plug in where a -A was, but the internal relay drivers or processor generation differs.
Second letter — software index: Changes when the firmware revision changes. A higher software index normally accepts the same coding data as a lower one, but this is not guaranteed across a hardware generation boundary.

When sourcing from GiantParts or any reputable used-parts supplier, always quote the full number including the suffix from your original module’s label, not just the main catalogue reference. A seller who cannot provide the suffix label has probably not tested the unit properly.

GM1, GM3 and GM5 — Three Different Modules Under Similar Numbers

The Gemischtes Modul (GM) family spans three generations across these platforms:

GM1 (E38): First generation with CAN capability added late in production. Earlier E38 units use K-line only. Mixing CAN and non-CAN variants in the same car causes fault cascades in the instrument cluster and the EWS chain.
GM3 (E39): Fully CAN-integrated from production start. Handles central locking, windows, interior lighting and the gateway functions between the vehicle CAN and the body bus. Connector layout differs from GM1 and the two are not physically interchangeable.
GM5 (E46): Expanded to manage heated mirrors, rain sensor output and — on later builds — the first elements of footwell lighting. The E46 coupe and convertible use a separate part number family from the saloon because the body CAN node addressing is different from the factory.

None of these modules crosses between platforms. The physical connector housings differ. Even where a pin layout looks similar, the CAN addresses, the EEPROM coding maps and the software images are platform-specific. An E39 GM3 does not become an E46 GM5 through coding — the hardware is fundamentally different.

OEM Part Numbers — Specific References

These are the core references relevant to used-parts sourcing on these three platforms:

61 35 6 901 910 — E46 saloon, standard
61 35 6 901 911 — E46 saloon, folding mirrors
61 35 6 924 786 — E46 coupe/convertible
61 35 8 368 784 — E39 GM3 main variant
61 35 8 375 500 — E38 GM1 with memory seat
61 35 8 375 501 — E38 GM1 without memory seat

Always cross-reference against the vehicle’s Fahrzeugauftrag (production order) via ETK or ISTA before ordering. The production order tells you exactly which comfort module variant was installed at the factory — which is the only true baseline for a replacement. A related diagnostic guide is Кои BMW E38 7-Series модули са взаимозаменяеми с E39 и E38 варианти.

Error Codes Associated With a Mismatched or Faulty Comfort Module

When the comfort module is missing, failed or the wrong variant, the following codes appear in ISTA-D or INPA depending on the platform:

E46 — 0x16 (internal GM5): EEPROM checksum error — usually a dead or incorrectly coded replacement
E46 — 0x80: Initialisation failure on the rain sensor bus — appears when a non-rain-sensor GM5 is coded as a rain-sensor variant
E39 — A006: GM3 no communication — CAN dropout, common after water ingress at the footwell connector
E38 — 0xE1 (in GM1 self-test): EEPROM variant mismatch after replacement with wrong suffix variant
Cross-platform: EWS fault 0x71 can appear in the instrument cluster if the GM loses power during coding — it does not indicate an EWS failure unless the condition persists after GM coding is complete

Засегнати превозни средства

The GM1/GM3/GM5 comfort module family covers BMW production from approximately 1994 through to 2005 on these three platforms:

BMW E38 7-Series: 1994–2001, all engines, LWB and SWB variants
BMW E39 5-Series: 1995–2003, saloon and touring, all engine variants including M5
BMW E46 3-Series: 1998–2005, saloon, touring, coupe and convertible

The M5 E39 uses the same GM3 part numbers as the standard E39 — the M5-specific equipment differences are handled through coding rather than different hardware, which is one reason a standard E39 GM3 can be fitted to an M5 if coding is applied correctly.

Често задавани въпроси

Can I fit an E39 GM3 comfort module into an E46?

No. The GM3 and GM5 use different connector housings, different CAN node addresses and different software images. The modules are not physically interchangeable, and no amount of coding makes one platform’s unit function correctly in another. Always match the generation to the platform.

Does the last digit of an E46 GM5 part number really matter?

Yes, in practice it does. The difference between 61 35 6 901 910 and 61 35 6 901 911 is the folding mirror hardware support. Fitting the non-folding variant to a car with folding mirrors leaves the mirrors without fold control, and the module will log an initialisation fault. It will code without error, but the function will be absent. For additional context, read Кои модули споделя BMW E46 с E39 и E36 в различните варианти.

What tool do I need to code a replacement comfort module on the E46?

INPA with the correct script files (ZCS coding), PA-Soft, or ISTA-P covers E46 GM5 coding. The process writes the vehicle order code into the module’s EEPROM. Without coding, the replacement runs in a default state that often disables rain sensor, heated mirror and interior lighting logic. A K+DCAN cable and a laptop running the appropriate BMW software is the minimum equipment needed.

How do I find the part number on the module itself without removing it?

You cannot reliably — the label is on the module body, which on the E46 is behind the glovebox or under the rear parcel shelf depending on body variant. On the E39 it sits behind the driver’s kick panel. Reading it through ISTA-D or INPA is possible if the module communicates: the part number stored in EEPROM appears in the control unit identification screen. However, EEPROM data can be corrupt or overwritten, so always verify against the physical label when the module is out of the car.

Why does GiantParts ask for the suffix letters when I order a comfort module?

Because two modules with the same 11-digit base number but different suffix letters may carry different hardware revisions or firmware generations. Supplying the full label reference — including the suffix — allows the part to be matched to a tested unit from stock that is confirmed compatible with your exact vehicle build. A unit without a verified suffix creates unnecessary diagnostic risk after fitting.

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