Which BMW E90 Modules Are Shared With the E91 E92 and E93
The BMW E9x generation — E90 saloon, E91 Touring, E92 Coupé and E93 Convertible — runs on a shared electrical backbone, and a large proportion of the control units are identical across body styles. However, the assumption that “all E9x modules interchange” causes real problems in practice. Equipment level, engine variant, production date and body-specific functions each narrow compatibility, and fitting the wrong part can leave you with a module that communicates but codes wrong, or one that is physically identical but refuses to initialise.
How the E9x Platform Is Structured Electrically
All four E9x variants share the same PT-CAN and K-CAN bus architecture introduced on the E60. The CAS module, DME, ABS/DSC unit, instrument cluster and footwell module all sit on overlapping networks, which is why so much hardware is common. The key split is between body-neutral modules — engine management, braking, security — and body-specific modules that have different software variants even when the hardware part number looks the same.
Production ran from 2004 to 2013 for the family as a whole, with mid-cycle updates in 2008 bringing revised software on several units. Modules built before and after this revision are often physically identical but not functionally interchangeable without re-coding. Any used unit must be matched by hardware number first, then confirmed by the build-date suffix.
Modules That Interchange Freely Across E90, E91, E92 and E93
DME / engine control module
Engine management units are tied to engine code, not body style. A Bosch MEV17.2 from an E90 330i fits an E92 330i subject to normal DME coding and EWS/CAS synchronisation. The same applies to N47 diesel units (Bosch EDC17C06) across saloon, Touring and Coupé. What you cannot do is cross engine families — N52 and N54 units share no hardware. OEM numbers in this family include 7 566 964, 7 584 921 and 7 798 327 for common N52 variants; always confirm the full 11-digit suffix before ordering. For comparison, see Кои модули на BMW E90 са споделени с E91, E92 и E93.
ABS / DSC control module
The Bosch DSC8 and later DSC8+ units are body-neutral. A module from an E91 320d fits an E90 320d, an E92 320d and an E93 320d provided the part numbers align. The hydraulic block is a separate component from the control unit; only the electronic controller is being discussed here. Common OEM numbers: 6 769 852, 6 785 996, 6 851 471. Rear-wheel-drive and xDrive variants carry different part numbers and are not interchangeable — the xDrive unit carries wheel speed logic for all four corners plus transfer case inputs.
CAS module
The CAS3 and CAS3+ units are hardware-identical across the E9x family. The CAS must always be paired to the DME and the key — it is never plug-and-play — but the physical module from any E9x body will work in any other once programmed. OEM numbers include 6 135 445 and 6 978 869. CAS3+ (post-2008 on most variants) introduced additional anti-clone measures; always confirm CAS generation before buying.
Instrument cluster
The cluster hardware is body-neutral; the software variant configures it for speedometer scaling, fuel tank size and active warning channels. A used cluster from an E91 can be fitted to an E90 but requires mileage transfer and variant coding. OEM numbers: 6 214 891, 6 939 266, 6 970 398. The high-resolution Business cluster and the Professional cluster use different LCD boards internally — physically they look identical but the part numbers differ.
Modules That Are Body-Specific and Do Not Freely Interchange
Footwell module (FRM)
The FRM is the most body-specific module on the E9x platform. The E93 Convertible carries a separate soft-top control domain; the E91 Touring has rear hatch and load-area lighting channels; the E92 Coupé has frameless-window drop logic. These body functions are hard-coded into the FRM variant. Part numbers are distinct: E90 FRM is 6 135 663, E91 Touring is 6 135 664, E92 is 6 135 665, E93 is 6 135 667. Fitting an E90 FRM to an E93 will result in soft-top errors and frameless-window faults that cannot be coded away because the hardware outputs are missing.
Rear SAM / power distribution
The E91 Touring has a rear SAM unit that the saloon and coupé do not carry at all. This unit controls the rear socket, load compartment lighting, trailer socket and rear wiper. E90, E92 and E93 do not use this module; sourcing one from an E91 for any other body is pointless, and fitting one would confuse the K-CAN topology.
Comfort access module (CA)
Where fitted, the comfort access module varies by body because the number of door handles sending capacitive signals differs. The E93 Convertible adds soft-top handle detection. Hardware part numbers differ even when the modules look similar in photographs. A related diagnostic guide is Кои Модули BMW E90 Споделя с E91, E92 и E93.
xDrive Variants: A Separate Compatibility Layer
E90 xDrive (325xi, 330xi, 335xi) adds a transfer case module and revised DSC unit to the standard architecture. The xDrive DSC unit is not interchangeable with the rear-wheel-drive unit even on the same engine in the same body. The transfer case control unit is common across xDrive E90/E91/E92 but does not exist on E93 (no xDrive Convertible was offered). Always check the drivetrain suffix on any used module before buying for an xDrive car.
Error Codes Relevant to Module Mismatch
- A0A3 — CAS: ECU not coded (appears after CAS replacement without DME pairing)
- A0B0 — CAS: key not taught (after CAS or DME swap without key synchronisation)
- 5E08 — DSC: control unit variant fault (appears when wrong xDrive/RWD unit fitted)
- 93B2 — FRM: configuration mismatch (body-variant mismatch in footwell module)
- C3B3 — Instrument cluster: variant coding required (after cluster swap without coding)
OEM Part Numbers to Confirm Before Ordering
Always read the full number off the physical unit in the car, including the two-letter or three-digit suffix. The numbers below are representative starting points, not universal fits:
- DSC control unit (RWD, N52/N54): 6 769 852, 6 785 996
- CAS3 module: 6 135 445
- CAS3+ module: 6 978 869
- Instrument cluster (standard): 6 214 891, 6 939 266
- FRM E90 saloon: 6 135 663
When ordering from GiantParts, supply the number stamped on the original unit. A match on the base number alone is not sufficient when suffix letters differ — those letters encode hardware revision and software variant.
Засегнати превозни средства
This guide covers the full E9x production range: E90 saloon (2004–2011), E91 Touring (2004–2012), E92 Coupé (2005–2013), E93 Convertible (2006–2013). Engine variants covered include N46, N52, N54, N55, M54 carryover, N47 diesel and M57 diesel. Build dates before and after the 2008 LCI update are both addressed.
Често задавани въпроси
Can I fit an E91 Touring DSC module into my E90 saloon?
Yes, provided both are rear-wheel-drive and the base part numbers match. The DSC unit on the E9x platform is body-neutral. However, confirm the full part number including suffix, and have the module variant-coded after fitting to clear any mismatch codes. For additional context, read Кои варианти на DSC модули за BMW E90 са взаимозаменяеми и кои не са.
Does the CAS module from any E9x body fit any other E9x?
The hardware is identical across all four body styles. The CAS must still be programmed to match the DME and keys — it is never a direct swap — but you are not restricted to the same body when sourcing a used unit. CAS3 and CAS3+ are not interchangeable with each other.
Why does the E93 need a different footwell module from the E90?
The E93 FRM controls the electro-hydraulic soft-top, the frameless window drop sequence and the convertible-specific lighting channels. These outputs are absent on the E90 saloon FRM hardware. Fitting an E90 FRM to an E93 will generate persistent roof and window faults because the required control channels do not exist on the donor unit.
Will the engine control unit from an E92 335i fit an E90 335i?
Yes. The DME is matched to engine code and variant, not body style. Both use the Bosch MEVD17.2 on the N54 engine. Normal CAS-DME synchronisation and VIN coding are required after fitting. The process is identical regardless of which E9x body the donor unit came from.
Does an xDrive ABS module interchange with a standard RWD unit on the E90?
No. The xDrive DSC module carries additional software for all-wheel-drive torque distribution and interfaces with the transfer case module. Fitting an xDrive unit to a RWD car will generate DSC variant faults immediately. The part numbers are distinct and should be checked carefully when buying a used unit.
Намерете проверени оригинални електронни части и модули на адрес:
https://giantparts.eu/
