A 2011 Jetta TDI with a KermaTDI Stage 1 tune is experiencing issues with the immobilizer and cooling fans. The fans run continuously after the ignition is off, draining the battery. Replacing the battery doesn’t solve the problem, and the instrument cluster displays “Immobilizer Active – SAFE.” Various troubleshooting steps, including disconnecting the battery and leaving the ignition on, haven’t resolved the issue. A full VCDS scan reveals several fault codes across multiple modules.
VCDS Scan Results and Analysis for 2011 Jetta
The following fault codes were identified using VCDS Release 23.3.0:
Address 01: Engine (CJA)
- 001152 – Coolant Fan Control Circuit 1 (P0480): This code indicates a problem with the electrical circuit controlling the cooling fans. This likely explains why the fans are constantly running and draining the battery. Further diagnosis of the wiring, relays, and fan control module is necessary.
- 005488 – Engine Start Blocked by Immobilizer (P1570): This is the root cause of the “Immobilizer Active – SAFE” message. The immobilizer is preventing the engine from starting due to a potential issue with the key, immobilizer module, or engine control module (ECM).
Address 03: ABS Brakes (J104)
- 01325 – Control Module for Tire Pressure Monitoring (J502) (No Signal/Communication): This suggests a communication problem with the tire pressure monitoring system (TPMS). While likely unrelated to the primary issues, it should be addressed separately.
Address 08: Auto HVAC (J301)
- 13701888 – Function Restriction due to Faults in Other Modules (U1113): This code confirms that the HVAC system’s functionality is limited due to faults in other modules, likely related to the engine and immobilizer issues.
Address 19: CAN Gateway (J533)
- 01304 – Radio (No Signal/Communication – Intermittent): Points to an intermittent communication issue with the radio. This may be unrelated to the main problems.
- 01303 – Telephone Transceiver (R36) (No Signal/Communication): Indicates a communication problem with the telephone module. Likely unrelated to the primary issues.
Address 25: Immobilizer (J334)
- 9456128 – Engine Control Module (ECM) not authorized (B104A): This critical code confirms that the ECM is not authorized by the immobilizer, preventing engine start. This often requires specialized procedures or tools to re-authorize the ECM.
- 9456681 – Key (B104C) Implausible Signal: This suggests a problem with the key’s transponder chip or the immobilizer’s ability to read the key signal. Trying a spare key or checking the key for damage is recommended.
Address 44: Steering Assist
- 03803 – Steering Angle Sensor for Steering Aid: This code indicates a problem with the steering angle sensor, which could affect various systems, including stability control and power steering. While possibly unrelated to the starting issue, it requires further investigation.
Conclusion and Next Steps
The VCDS scan of this 2011 Jetta reveals significant issues with the immobilizer system and cooling fan control circuit. The P1570 (Engine Start Blocked by Immobilizer) and B104A (ECM not authorized) codes suggest a likely need for immobilizer component replacement or reprogramming using specialized equipment. The P0480 (Coolant Fan Control Circuit) code requires further diagnosis of the fan wiring, relays, and control module. Addressing these issues requires advanced automotive knowledge and tools. Consulting a qualified Volkswagen technician or a specialist familiar with VCDS and immobilizer systems is strongly recommended.
