Infrared Remote Central Locking Transmitter Service (80/22)

Publication date: 1995-09-01
Reference number: 80/22

INFRARED REMOTE CENTRAL LOCKING TRANSMITTER SERVICE

TECHNICAL SERVICE BULLETIN

Reference Number(s): 80/22, Date of Issue: September 1995

ALL MODELS, MODEL YEAR 1996 INFRARED REMOTE CENTRAL LOCKING (RCL)

A. ORDERING REPLACEMENT INFRARED (IR) TRANSMITTER

B. CHECKING IR TRANSMITTER BATTERIES

C. CHECKING IR TRANSMITTER SIGNAL

D. SYNCHRONIZATION OF IR TRANSMITTER

E. IR TRANSMITTER APPROVAL, BLOCKING OR IRREVOCABLY BLOCKING

F. REPLACEMENT COMPONENTS OF RCL

Model(s): 1996 Mercedes-Benz, All Models

Group: 80 - Central Locking, Infrared Central Locking (IRCL)

Bulletin No.: 80/22

Date: September 1995

SERVICE INFORMATION

This Service Information provides new information, as well as information already provided in the Diagnostic Manual, Models 129 and 140, Body and Accessories, Volume 1, section 4 for specific models/model years.

ILLUSTRATIONS

Fig 1: IR Transmitter Identification Number Location

Fig 2: IR Transmitter

Fig 3: RCL Receiver On Rearview Mirror

A. ORDERING REPLACEMENT INFRARED (IR) TRANSMITTER

As of model year 1996, part numbers for IR transmitters have changed. Please refer to the PARTS INFORMATION TABLE for details.

It is important to order the proper part number for the vehicle model year in question, otherwise the Remote Central Locking (RCL) will not function. Any discrepancies should be discussed with your facing PDC.

IMPORTANT: IR transmitters are identified via an engraved numeral in the transmitter housing battery compartment. See Fig 1 enlargement). IR transmitters supplied with the vehicle are identified via the numerals 1 and 2. Up to 5 additional IR transmitter ID's are available for each vehicle and are numbered 4 - 8.

The RCL control module (N54) retains a memory position for each one of the IR transmitters used. For example, if a replacement IR transmitter has the same identification number as an existing IR transmitter, the existing IR transmitter will be automatically de-synchronized by the RCL control module upon synchronizing of the (new) replacement IR transmitter (see D. SYNCHRONIZATION OF IR TRANSMITTER ).

B. CHECKING IR TRANSMITTER BATTERIES

A LED indicator will illuminate in the IR transmitter window (a) of the IR transmitter, after pressing and holding IR transmitter button (b) for more than 1 second, indicating that the batteries are OK. See Fig 2 . Should the LED diode not illuminate, check the battery contacts or replace the batteries as necessary.

C. CHECKING IR TRANSMITTER SIGNAL

The IR transmitter signal can be visually verified by via an IR Signal Indicator Card, which can be obtained via an electronics store (i.e. Radio Shack 276-0099). For testing, please follow the instructions supplied with the IR signal indicator card. To determine if the IR transmitter signal is received by the RCL receiver, follow the test procedure as indicated in the Diagnostic Manual for the respective model/model year.

IMPORTANT: It is not possible to determine if the transmitter IR signal is correctly coded or not.

D. SYNCHRONIZATION OF IR TRANSMITTER

NOTE: Depending on the production date, there are three procedures for synchronization of the IR transmitter.

MODELS 129, 140 UP TO NOVEMBER 1993 PRODUCTION

Point the IR transmitter window (a) toward an IR receiver and then press IR transmitter button (b) momentarily. See Fig 2 .
Using the mechanical key, lock or unlock vehicle within 30 seconds. This will synchronize and enable the control module to recognize the IR transmitter.

MODELS 129, 140 AS OF DECEMBER 1993 PRODUCTION THROUGH MODEL YEAR 1995

Point the IR transmitter window (a) toward an IR receiver and then press IR transmitter button (b) momentarily. See Fig 2 .
Using the mechanical key, switch on ignition within 30 seconds. This will synchronize and enable the control module to recognize the IR transmitter.

ALL MODELS, MODEL YEAR 1996

Point the IR transmitter window (a) toward RCL receiver (A26/7) in the interior rearview mirror and then press IR transmitter button b) twice momentarily. See Fig 2 and Fig 3 .
Using the mechanical key, switch on ignition within 30 seconds. This will synchronize and enable the control module to recognize the IR transmitter.

E. IR TRANSMITTER ENABLING, BLOCKING OR IRREVOCABLY BLOCKING

ALL MODELS, MODEL YEAR 1996

In M.Y. 1996 vehicles, using RCL control modules, part nos. 210 820 21 26 (refer to PARTS INFORMATION TABLE), IR transmitters can be enabled or blocked, or if an individual IR transmitter is lost by the vehicle owner, irrevocably blocked via the Hand-Held Tester (HHT). The enabling, blocking or irrevocable blocking of the IR transmitter is menu driven, as of HHT module edition 2.02.

IMPORTANT: IR transmitters should be irrevocably blocked only upon consent of the vehicle owner, since irrevocably blocked IR transmitters can never be recoded again.

All vehicles are supplied with IR transmitters "1" and "2", as engraved in the IR transmitter housing battery compartment See Fig 1 (enlargement). Any subsequently purchased IR transmitters retain the numerals "4" through "8". Should an IR transmitter be lost, determine which IR transmitter to block by inspecting the remaining IR transmitter(s) on hand. By recording the ID number (Fig. Fig 1 ) in the battery compartment of the remaining IR transmitter(s), the IR transmitter which must be blocked can be determined by process of elimination.

F. REPLACEMENT COMPONENTS OF RCL

ALL MODELS, MODEL YEAR 1996

The RCL control module (N54) and engine control module (N34) (component designation varies with engine) are "married" together via an identification code. During each starting attempt, the engine control module asks the RCL control module (via the CAN bus) for its identification code. If the returned code from the RCL control module does not match the code in the engine control module's memory, the engine will not start. It is therefore impossible to swap control modules (either RCL or engine control) for troubleshooting purposes. The RCL and engine control module identification codes cannot be changed, and this code remains with the vehicle for its service life. The complete lock codes (both mechanical and infrared) that were originally assigned to the vehicle are noted on a label affixed to the RCL control module.

Fig 4: LOCK NUMBER CODE (EXAMPLE)

ADDITIONAL LOCK CODE INFORMATION

Before July 14 1995, the lock number code was structured: 24975800 10390307.

After July 14 1995, the lock number code was restructured to: 2497580 01039030 7

REPLACEMENT OF CONTROL MODULES

If the RCL control module must be replaced for any reason, a specially programmed module for the specific vehicle must be ordered from your facing PDC. The programming code must be the same as the originally installed module. If the engine control module must be changed for any reason, the module received as a spare part is unprogrammed and must be programmed to the RCL control module identification code. Once this is done, the engine control module is "married to that specific vehicle and cannot be used in any other vehicle. The programming occurs automatically after a few starting attempts or can be performed manually with the Hand-Held-Tester (HHT). Therefore, it is not advisable to install any engine control module for temporary testing or troubleshooting as it either will not contain the correct identification code (and the engine will not start) or it will become "married" to that vehicle (and cannot be used in any other vehicle). Warranty claims for engine control modules accidentally "married" to a vehicle will be denied.

If the customer loses an IR transmitter (which includes a mechanical key):

Vehicle's RCL number code remains, and the lost IR transmitter is de-synchronized via the RCL control module and the HHT and blocked (until key is possibly found) or irrevocably blocked (obtain vehicle owner approval) which renders the lost IR transmitter useless.
To maintain vehicle security, all mechanical locks should be changed, using a new mechanical lock number code. Lock changes must be reported, using the Lock Change Notice Form. See Parts Information 11651, section 3, dated April 2, 1993 for details.

If the RCL control module is defective:

A new RCL control module must be specially ordered for the specific vehicle, using the same RCL identification code as the previously installed RCL control module.

If a mechanical lock or key is defective:

Replace the defective lock (or key) with a new one, using the same mechanical lock number code (specially ordered from your facing PDC). Lock changes must be reported, using the Lock Change Notice Form. See Parts Information 11651, section 3, dated April 2, 1993 for details.

If an engine control module is defective:

Order a replacement module in the usual manner. Replacement modules received from spare parts are unprogrammed. The engine control module will either program itself automatically after a few engine starts or it can be programmed manually using the Hand-Held-Tester (HHT).

PARTS INFORMATION

Fig 5: PARTS INFORMATION - MODEL YEAR 1996