Components
- Radio frequency DAS control module (N54/3), model 170 andnd 168 only
- DAS control module (N73/1), model 168 only (SA)
- Radio frequency DAS control module (N54/4), models 129 and 140 only
- Transmitter key and mechanical key with transponder coil on steering lock (L11)
- Left front door IR receiver (A26/1) and right front door IR receiver (A26/2), models 129/140 only
- front door lock switch (CF) (S86/1) on LHS, (S87/1) on RHS and trunk lid lock switch (CF) (S88/2)
Notes
Radio frequency DAS control module (N54/3) or radio frequency /infrared DAS control module (N54/4)
The functions a) and b) are performed by the radio frequency DAS control module (N54/3) or radio frequency/infrared DAS control module (N54/4).
DAS control module (N73/1)
Only the functions listed under b) are performed by the DAS control (N73/1)
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a) Radio frequency/infared remote control
- Reception and evaluation of radio signals
- Reception and evaluation of infrared signals, models 129 and 140 only
- Actuation - of central locking (CL)
- of remote trunk release (RTR), models 129 and 140 only
- of anti-theft alarm (ATA),
- of convenience feature (CF), models 129 and 140 only
- of visual feedback via the turn signal system, models 129 and 140 via the combination relay module (N10/2), model 170 via the lock confirmation relay (K54)
- reading and evaluating mechanical lock (convenience) switch
b) Stage 2b drive authorization (DAS 2b)
- Actuation of transponder coil on steering lock
- Reading and evaluating transponder signal
- Engine control module enable via CAN with valid transponder code
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Drive authorization is independent of the security status of the radio/infrared remote control and the batteries in the transmitter key.
The only prerequisite is that the transponder in the key transfer the data to the radio frequency DAS remote control (N54/3), the DAS remote control (N73/1) or the radio frequency/infrared DAS remote control (N54/4) via the transponder coil (L11) in the ignition/starter switch.
If this data is recognized as valid the vehicle is enabled for starting.
If the transponder is not valid or the power for the transponder cannot be built up, the engine control is not enabled. This is indictated by the "start error" indicator lamp in the instrument cluster. It is controlled by the engine control module.
The engine control is disabled via the radio frequency DAS control module (N54/3), DAS (N73/1) or radio frequency/infrared DAS (N54/4). These are connected to the engine control module via a CAN data bus. Once the engine control is disabled (key is removed from the ignition lock), the engine control module renders the injection system inoperative.
The radio frequency DAS control module (N54/3) or the radio frequency/infrared DAS control module (N54/4) are permanently assigned to each other by an identification code. This identification cannot be erased.
Replacement of the radio frequency DAS control module (N54/3) or radio frequency/infrared DAS control module (N54/4) from another vehicle on an experimental basis is therefore not possible.
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Actual values
Up to 8 transmitter keys corresponding to one locking mechanism can be checked for authorization using the Hand-Held Tester. The synchronization of the individual transmitter keys can also be checked. The HHT also displays the number of the current transmitter key last used. It also displays whether the variant coding is disabled, i.e. after approx. 250 operations of "terminal 15 On" the radio frequency DAS control module (N54/3) or radio frequency/infrared DAS control module (N54/4) are permanently assigned to the vehicle and only minor modifications can be made to the variant coding. The interrogation of actual values is menu-assisted.
Disabling transmitter key/transponder
Transmitter keys can be disabled revocably using the HHT. The revocable disabling of certain transmitter keys is menu-assisted. Transmitter keys disabled revocably can be re-authorized using the HHT. The transmitter function and transponder function are disabled or re-authorized together.
Transmitter keys can be disabled irrevocably using the HHT (only at the customer's request). The irrevocable disabling of certain transmitter keys is menu-assisted. Transmitter keys disabled irrevocably cannot be re-authorized. The radio frequency/infrared transmitter function and the transponder function are disabled together.
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Variant coding
When the radio frequency DAS control module (N54/3), DAS control module (N73/1) or radio frequency/infrared DAS control module (N54/4) is replaced, version coding with the HHT is required. After accessing the actual values menu, the module number used to carry out the last variant coding is displayed automatically. Variant coding is menu-assisted.
The radio frequency DAS control module (N54/3) or radio frequency/infrared DAS control module (N54/4) and the engine control module are permanently assigned to each other by means of an identification code. For this reason the RFL/RCL locking mechanism number part of the lock must remain in the vehicle throughout the vehicle's service life, i.e. only the mechanical part of the locking mechanism number may change.
This means that if a transmitter key is lost:
The RFL/RCL locking mechanism number part is retained invalidate transmitter key lost by disabling.
Change mechanical part of the locking mechanism number fit complete mechanical locking mechanism with new locking mechanism number. It is absolutely essential to send a sticker with the 8-digit locking mechanism number, stating the VIN, to Dept. VP/AM, Mercedes-Benz AG, 70322 Stuttgart.
This means that if a radio frequency DAS control module or radio frequency/infrared DAS control module is defective:
The RFL/RCL locking mechanism number part is retained fit new radio frequency DAS control module or radio frequency/infrared DAS control module with the same locking mechanism number.
This means that if a mechanical lock part is defective:
The locking mechanism number is retained replace lock part whilst retaining the locking mechanism number.