Audi A4 B5 Comfort Control Module OEM Numbers and Replacement
The comfort control module in the Audi A4 B5 — known internally as the Komfortsteuergerät — is a small but critical unit that governs central locking, electric window operation, interior lighting, and in some variants the sliding sunroof. When it fails, the symptoms often look like multiple unrelated faults at once, which leads many owners and workshops to waste time chasing wiring before the module is even considered. A used OEM replacement is a cost-effective solution, provided the part number and vehicle configuration are matched carefully before installation.
What the Comfort Module Controls on the B5
On the Audi A4 B5 (1994–2001), the comfort module sits behind the dashboard trim or in the driver’s door area depending on build year and market. It receives inputs from door switches, the central locking button, the key fob receiver, and the ignition. It then controls the door lock actuators, regulates how windows close automatically on locking (convenience closing), and manages the interior lighting delay after door closure.
Vehicles with the factory alarm or the optional one-touch window closing function have a slightly different module variant — and this matters enormously when sourcing a replacement. Fitting the wrong sub-variant can result in features either not working at all or behaving erratically even if the module is electrically healthy.
Typical Failure Symptoms
- Central locking works intermittently or not at all from the key fob
- One or more doors fail to lock or unlock even when others respond correctly
- Windows stop responding to the one-touch function but still work manually
- Interior lights do not delay correctly after door closure — either switching off immediately or staying on indefinitely
- Ghost locking: doors lock and unlock on their own with no input
- No response from remote locking, even with a known-good battery in the key fob
It is worth confirming that the door lock actuators and individual window regulator motors are working before condemning the module. A module supplying correct signals to a dead actuator will be blamed incorrectly. A basic wiring continuity check and actuator direct-power test takes only a few minutes and rules out those causes first. For comparison, see Audi A4 B5 Comfort Control Module Faults Common Failures and Repair.
Relevante Fehlercodes
VAG diagnostic tools (VCDS, OBD-Eleven, or older VAG-COM) typically access the comfort electronics under address 46. Common fault entries include:
| Code | Beschreibung |
|---|---|
| 01042 | Control module defective — internal fault detected |
| 01044 | Control module incorrectly coded — variant mismatch |
| 00987 | Central locking switch — implausible signal |
| 01176 | Door contact — open circuit or short to ground |
| 00290 | Remote control — no signal received or frequency mismatch |
Code 01044 is particularly common after a replacement. It indicates the module coding does not match the vehicle equipment — for example, a module coded without alarm fitted into a car that has one. The coding value must match the original unit’s configuration, which is why retaining the old module’s coding byte or worksheet from the previous workshop is helpful.
OEM Part Numbers for the Audi A4 B5 Comfort Module
The B5 platform spans several years and a range of body styles — sedan, Avant, and Cabriolet — with differing equipment levels. Part numbers vary accordingly. The following are typical OEM references for the comfort control module:
- 8D0 962 258 A — early B5 sedans and Avants without alarm, base equipment
- 8D0 962 258 C — mid-production, includes convenience closing support
- 8D0 962 258 E — later B5 and 1.8T variants with alarm pre-wiring
- 8D0 962 258 G — Avant and quattro models with extended locking features
- 8D0 962 258 H — Cabriolet-specific variant, includes hood open-circuit inputs
- 8D0 962 258 K — late facelift (1999–2001), updated firmware revision
Always cross-reference the number on the original module against Audi parts documentation or a trusted VAG parts catalogue before purchasing. A suffix letter difference can mean a completely different equipment scope. Simply buying the cheapest listed unit without checking the suffix is one of the most common — and avoidable — mistakes. A related diagnostic guide is Audi A4 B5 Instrument Cluster Dead Display and Mileage Loss.
Does the Replacement Module Need Coding?
Yes, in most cases. Replacement comfort modules for the B5 require adaptation via VCDS or compatible VAG diagnostics. The process involves entering the correct coding value that matches the vehicle’s options: alarm status, convenience closing, interior sensor presence, and other fitted features. This is not complex work, but it does require the right software and knowledge of the original vehicle coding. A module installed with default or incorrect coding will often behave unpredictably — doors may lock but not unlock, or windows may not close on remote locking.
Some later B5 modules may also require a brief adaptation run after coding — locking the car several times with the key to synchronize the remote control channel.
Affected Vehicles and Platform Notes
The Audi A4 B5 was produced from late 1994 through to 2001, covering 1.6, 1.8, 1.8T, 2.4, 2.8, 1.9 TDI and 2.5 TDI engine variants. All body styles share the same basic comfort module architecture, though Cabriolet and quattro variants require specific module numbers. The Audi A4 B5 also shares significant platform DNA with the Passat B5 (3B), but comfort module numbers are not cross-compatible across brands — do not use a VW Passat comfort unit in an Audi B5.
Häufig gestellte Fragen
Can I fit a used comfort module from another Audi A4 B5?
Yes, a used module is a good option provided the OEM suffix matches your original unit. After installation the module will need coding via VCDS. If the donor vehicle had a different equipment level — such as alarm fitted versus non-alarm — the module may need reconfiguring, and in some cases certain features may remain dormant if the vehicle wiring does not support them.
Why does my central locking work from the door button but not from the key fob?
If locking works manually but not remotely, the fault is often in the fob receiver module or the fob itself, not the comfort module. However, if diagnostics show code 00290 and swapping the fob does not help, the receiver circuit inside the comfort module may have failed. The B5 has an integrated RF receiver on some builds, making the module itself the fault point in that scenario. For additional context, read Audi A4 B5 ABS Control Module Failure: Symptoms and Repair.
How do I find the coding value for my replacement module?
The original coding value is stored in VCDS logs if the car was previously scanned. Alternatively, your vehicle’s options sticker in the spare wheel well or boot lid often lists equipment codes that help determine the correct comfort coding value. Audi dealers can also retrieve the original coding from the vehicle identification number in some cases.
My windows stopped doing the one-touch close after I replaced the battery. Is the module damaged?
Probably not. After a battery disconnect the window regulators often lose their end-stop memory. In the B5 this usually requires operating each window to its fully open and fully closed position using the manual button, held at the end position for two seconds. This re-teaches the regulator limits. If this does not restore the function, then a comfort module or regulator fault is worth investigating.
Is the comfort module the same part as the door control module?
No. The B5 has both a central comfort control module — typically mounted in the dashboard area — and individual door electronics integrated into each door locking actuator or regulator unit. The comfort module sends commands; the door components execute them. Replacing the comfort module will not fix a dead actuator in a single door, and vice versa.
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