The following functions are performed by the IR DAS control module:
a) Infrared remote control
- Reception and evaluation of infrared signal
- Actuation of central locking (CL)
of remote trunk release (RTR), (only models 140, 202 sedan, 210 sedan, model 140)
of anti-theft alarm (ATA),
of convenience feature (CF)
of visual feedback in interior rearview mirror (not model 170)
of visual feedback via the turn signal system (models 129, 140 via combination relay module (turn signal with trailer coupling, rear window defroster, wiper motor, ATA (N10/2)), models 170, 202, 210 via lock confirmation relay (K54), models 202, 210 in addition via lock confirmation relay (Japan) (K54/1)
Reading in and evaluating the manual lock convenience switch or actuators, ( only)
b) Stage 2a drive authorization (DAS2a)
- Actuation of transponder coil on steering lock
- Reading in and evaluating the transponder signal
- Engine control module enable via CAN with valid transponder code.
Drive authorization is independent of the security status of the infrared remote control and batteries in the infrared transmitter key.
The only condition is that the transponder in the key transmits the data to the IR DAS control module (N54/1) via the coil (L11) in the ignition/starter switch. If this is recognized as correct, start enable follows.
The engine control is disabled via the IR DAS control module. The IR DAS control module is connected to the engine control module via a CAN data bus. Once the engine control is disabled (key is removed from the steering lock), the engine control module renders the injection system inoperative.
Actual values
Up to 8 IR transmitter keys which fit one locking mechanism can be checked for approval using the Hand-Held Tester. The condition of the battery and the synchronization of the individual IR transmitter keys can also be checked. In addition, the HHT displays the number of the current IR transmitter key last used. Furthermore, the display shows whether the variant coding is disabled. In other words, after approx. 250 operations of terminal 15 On, the IR DAS control module is permanently assigned to the vehicle and variant coding can no longer be changed. Interrogation of the actual values is menu-assisted.
Disabling the IR transmitter key/transponder
IR transmitter keys can be disabled revocably using the HHT. Disabling particular IR transmitter keys revocably is menu-assisted. An IR transmitter key which has been disabled revocably can be re-authorized using the HHT. The IR transmitter function and the transponder function are disabled or re-authorized together.
IR transmitter keys can be disabled irrevocably using the HHT (only at the customer's request). Disabling particular IR transmitter keys irrevocably is menu-assisted. An IR transmitter key disabled irrevocably cannot be re-authorized. The IR transmitter function and the transponder function are disabled together.
Variant coding
When replacing IR DAS control modules, variant coding must be carried out using the HHT. After entering the variant coding menu the module number, with which variant coding was last carried out, is displayed automatically. Variant coding is menu-assisted.
The IR DAS control module and engine control module are permanently assigned to each other by an identification code. For this reason, the infrared locking mechanism number of the locking mechanism must remain in the vehicle over its entire life, i.e., only the mechanical locking mechanism number may be changed.
This means that if a transmitter key is lost:
The RCL locking mechanism number is retained invalidate lost IR transmitter key by disabling.
Change the mechanical locking mechanism number install mechanical locking mechanism with new locking mechanism number all round. A sticker with the 8-digit locking mechanism number, stating the VIN, must be sent to Dept. VP/AM, Mercedes-Benz AG, 70322 Stuttgart.
This means that if the IR DAS control module is defective:
The RCL locking mechanism number is retained install new IR 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 while retaining the locking mechanism number.