The dreaded “Vcds Error 37” often leaves VW and Audi owners scratching their heads. This error, specifically “requiredTimeDelayNotExpired,” indicates a security lockout within the EDC16 engine control unit (ECU). This article delves into the intricacies of this error, explaining its causes, and outlining the steps to resolve it.
EDC16 Security Access vs. EDC15 Login
It’s crucial to distinguish between the “security access” function in EDC16 ECUs and the “login” function in older EDC15 systems. Unlike EDC15, EDC16 ECUs do not have manual adaptation channels. Adaptations are handled automatically through “ECU learning.” However, EDC16 incorporates security layers to protect specific diagnostic routines, including reading, writing, and flashing the ECU.
Understanding VCDS Error 37: The Security Lockout
When a diagnostic tool like VCDS attempts to access secured functions, the EDC16 ECU requests a password. Incorrect password entries trigger a security counter. After four consecutive incorrect attempts, the ECU enters a security lockout, resulting in error 37. Even with the correct password, the ECU will refuse access until a specific time delay has elapsed.
This lockout mechanism is indicated by the error string: 7F,27,37. Here’s a breakdown:
- 7F: Negative response (session refused).
- 27: Security access requested.
- 37: requiredTimeDelayNotExpired (reason for refusal).
VCDS might display this as error 01 02, referencing the specific step within the diagnostic routine where the error occurred. The detailed error string (7F,27,37) is often encrypted within the device log.
Time Delay and Resetting the Lockout
The initial lockout duration is 20 minutes. Subsequent failed attempts double the delay, up to a maximum of 255 minutes (4 hours and 15 minutes). To reset the lockout:
- Leave the diagnostic interface (e.g., VCDS cable) connected and properly communicating with the vehicle.
- Keep the ignition key ON (engine OFF).
- Leave the driver’s door open.
- Wait for the required time delay to expire. 40 minutes often suffices, but it could take up to the maximum 255 minutes.
Bypassing the Lockout
After the time delay, the correct security access password (12233 for VCDS) can be entered. Specialized flashing tools often automate this process by inputting the correct code automatically. Some tuning companies might intentionally set the lockout duration to the maximum 255 minutes to deter unauthorized access to the ECU’s diagnostic routines, essentially implementing a form of read protection. This modification is typically stored in the EEPROM, leaving the flash memory (and the tuning itself) untouched.
Conclusion
VCDS error 37 signifies a temporary security lockout in EDC16 ECUs, triggered by repeated incorrect password entries. Understanding the mechanism behind this error and following the correct reset procedure are crucial for regaining diagnostic access. Patience is key, as the required time delay can be substantial. Utilizing the correct security access password (12233 for VCDS) or a specialized flashing tool is essential after the waiting period. Remembering the distinction between EDC15’s “login” and EDC16’s “security access” prevents confusion and ensures proper diagnostic procedures.
