Drive Authorization System DAS Fault

What this code means

The ECU detected a fault in the Drive Authorization System (DAS). The immobilizer is not releasing engine start authorization, preventing the engine from running. This is Mercedes-Benz proprietary anti-theft technology.

Symptoms

• Engine cranks but will not start
• Key warning light on
• No fuel injection signal
• No ignition spark
• DAS fault message on instrument cluster

Common causes

• Key transponder failure
• EIS (Electronic Ignition Switch) module fault
• DAS communication link corrupted
• ECU DAS data lost
• Steering column EZS module failure

Diagnostic steps

1. Check DAS communication with Mercedes diagnostic tool (Star Diagnosis)
2. Test key transponder recognition
3. Verify EIS module communication
4. Check DAS authorization data in ECU
5. Inspect wiring between EIS and ECU

Repair notes

Re-synchronize the DAS system using Mercedes Star Diagnosis; replace EIS module or key if defective.

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