This article details the troubleshooting process of a no-start condition in a Volkswagen using Vcds 17.0. The vehicle exhibits symptoms including starting and immediately dying, intermittent immobilizer and airbag warning lights, and a complete loss of instrument cluster function. A new battery and relay 460 (VW 1K0951253A) have already been installed.
Initial Diagnosis with VCDS 17.0 (Cluster OFF)
The first diagnostic scan was performed with the instrument cluster off and the car in a no-start condition. VCDS 17.0 revealed numerous fault codes across multiple modules, most notably a “Cannot be reached” status for both the Instrument Cluster (Address 17) and Immobilizer (Address 25). This points towards a potential communication issue.
Key fault codes from this initial scan include:
- Address 01 – Engine:
- P0506 – Idle Control System RPM Lower than Expected
- P2181 – Performance Malfunction in Cooling System
- U0155 – No Communication with Instrument Cluster
- P0513 – Incorrect Immobilizer Key
- Address 03 – ABS Brakes:
- No Signal/Communication with Instrument Cluster (J285)
- No Signal/Communication with Immobilizer
- Address 09 – Central Electrics:
- No Signal/Communication with Instrument Panel on Comfort CAN (J285)
- Address 19 – CAN Gateway:
- No Signal/Communication with Immobilizer
- No Signal/Communication with Instrument Cluster (J285)
Second Diagnosis with VCDS 17.0 (Cluster ON)
After managing to get the vehicle started and the instrument cluster functioning, a second scan was conducted. While some modules now showed “OK” status, communication errors with the Instrument Cluster (Address 17) and Immobilizer (Address 25) were now reported as “Sporadic.” This further suggests an intermittent communication problem. Additionally, a fault code appeared in the Steering Assist module (Address 44):
- Address 44 – Steering Assist:
- Steering Angle Sensor (G85) fault.
Post DTC Clear Scan with VCDS 17.0
All DTCs were cleared and another scan was performed. Most fault codes were cleared, however, several persisted:
- Address 01 – Engine: The same four fault codes remained: P0506, P2181, U0155, and P0513. This suggests these faults may be related to the original issue and not simply communication errors.
- Address 0F – Digital Radio: Three fault codes related to the satellite radio antenna remained. These are likely unrelated to the no-start issue.
Conclusion
Using VCDS 17.0, the diagnosis points toward an intermittent communication issue, potentially related to the instrument cluster or a wiring issue within the CAN bus system. The persistent engine codes (P0506, P2181, U0155, and P0513) even after clearing DTCs require further investigation. The P0513 (Incorrect Immobilizer Key) code specifically warrants attention as it could be contributing to the no-start condition. Next steps should include inspecting wiring harnesses and connections related to the instrument cluster, CAN gateway, and immobilizer. Further diagnostics using VCDS 17.0’s measuring block functions could help pinpoint the source of the communication breakdown.
