Hi all, first post! But have a check engine light on the car, which read "Emissions workshop" and I'm also experiencing limp mode issues if I put my foot flat to the floor, however if I key it off and on again it clears temporarily. So plugged the OBD scanner (TopDon) in for it to give back a communication error saying it cant read my car. Then plugged a second OBD scanner (SnapOn) in as thought it might be my scanner that is the problem, but nothing and the same message saying it cant find my vehicle or read any codes. Any help would be appreciated

Read on here someone with similar problems. They had an aftermarket radio that for some reason was stopping scanner connecting to obd port.

Ai came up with this which I think is correct. Not sure re fuse number

Troubleshooting Steps: 

• Check Fuse 12: Check the fuse box on the driver's side dashboard; fuse 12 (top section) is critical for OBD functionality.

• Remove Aftermarket Radio: A common issue in VAG cars is that aftermarket radios bridge the diagnostic K-Line, preventing tool communication. Pull the radio out and try the scanner again.

• Test for Power/Ground: Use a multimeter to check for

  12V12 cap V

  12𝑉

  at Pin 16 and a solid ground at Pin 4 of the OBD port.

• Inspect Connector: Ensure the port is firmly attached to the dash and pins are not pushed back.

• Try Another Scanner: Ensure the scan tool is compatible; some cheaper tools fail to link on older VAG models. 

If the port has no power, the issue is typically a fuse or power wiring; if it has power but no communication, focus on the radio or a faulty ECU. 

3 minutes ago, Alasdair1 said:

Read on here someone with similar problems. They had an aftermarket radio that for some reason was stopping scanner connecting to obd port.

Ai came up with this which I think is correct. Not sure re fuse number

Troubleshooting Steps: 

• Check Fuse 12: Check the fuse box on the driver's side dashboard; fuse 12 (top section) is critical for OBD functionality.

• Remove Aftermarket Radio: A common issue in VAG cars is that aftermarket radios bridge the diagnostic K-Line, preventing tool communication. Pull the radio out and try the scanner again.

• Test for Power/Ground: Use a multimeter to check for

  12V12 cap V

  12𝑉

  at Pin 16 and a solid ground at Pin 4 of the OBD port.

• Inspect Connector: Ensure the port is firmly attached to the dash and pins are not pushed back.

• Try Another Scanner: Ensure the scan tool is compatible; some cheaper tools fail to link on older VAG models. 

If the port has no power, the issue is typically a fuse or power wiring; if it has power but no communication, focus on the radio or a faulty ECU. 

Thanks mate, I appreciate this. I do have an aftermarket radio, so will disconnect fully and try without it installed or worst case get the multimeter out and test for power. I’ve heard the ecu’s drink water sometimes since they’re located under the scuttle panel so I’m hoping it’s not that!

Hope its just the radio/fuse and nothing major once you get the scanner to work.

Alasdair