Specifications

Testing Testing DAS (Immobilizer) Systems

control and traction control (ASR). Vehicles with ASR usually have an orange warning light on

the instrument cluster.

Note the following when testing EA/CC/ISC systems:

• The EA/CC/ISC modules are on the CAN bus and can turn the Check Engine Light on.

Always check, repair and clear any EA/CC/ISC codes.

• The ECU or other modules may also report a code pointing to a fault at the EA/CC/ISC.

Testing DAS (Immobilizer) Systems

The Drive Authorization System (DAS) is the name for the Mercedes Immobilizer system

combining vehicle access and drive authorization. Prior to 1996, DAS was separated from the

engine control module, and ignition switch operation was based solely on a mechanical key. An

early version of DAS was first introduced in approximately 1993 when Mercedes started

networking DAS, the engine, transmission, ABS, and traction control systems on a common data

bus called CAN.

The Mercedes pneumatic control door lock system has been in existence since the early 1980s,

and although now it is much more advanced, it is still in use today. It steadily became more

sophisticated as features were added like central locking, starter lock-out, and steering lock-out.

NOTE:

i Some late models, such as ML- and C-class series, have completely eliminated the pneumatic

control system and now use a fully electronic door lock system.

Central Locking

Central Locking is the ability to lock or unlock the complete vehicle at one time and from multiple

locations using either an infrared beam or a radio frequency signal. The infrared remote control

Table 4-1 1992–96 Mercedes EA/CC/ISC application coverage

Series Model Year Chassis # Engine #

124

300CE 1993–95 124.052/092 104.992

300E

1993 124.028 104.942

1993–95 124.032 104.992

400E 1992–95 124.034 119.975

500E 1992–94 124.036 119.974

140

300SE 1992–93 140.032 104.990

400SE 1992 140.042

119.971

400SEL 1993–95 140.043

600SEC 1993–95 140.076

120.980

600SEL 1992 140.057

S320 1994–96 140.032 104.994

202 C280 1994–95 202.028 104.941