OBD not communicating with ECU?

2003 VOLKSWAGEN POLO
300,000 MILES • 1.2L • 3 CYL • 2WD • AUTOMATIC
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BOFFVW9N
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  • 2 POSTS
Hi, I have used several obd2 adapters and none of them can communicate with ECU. Can anyone help please?
Oct 19, 2023 at 9:44 AM
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JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

The only information I have on the Polo is with a 1.6L engine and my manual has little to no information. Is that what you have? Also, when you connect to the data link connector, is there power present and does the scan tool turn on?

Let me know that first. If possible, check pin 16 in the data link connector (DLC). It should have battery voltage.

Let me know.

Joe
Oct 19, 2023 at 8:15 PM
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BOFFVW9N
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  • 2 POSTS
Hi and thanks for the reply. it 1.2 manual transmission and yes there is 12v on data link and the obd2 scanner power on but still no communication.
Oct 20, 2023 at 5:12 AM
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JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Check the wiring at the ECM to make sure nothing is loose or damaged. Also, make sure the connectors aren't corroded.

You may have a faulty ECM.

Let me know what you find,

Joe
Oct 20, 2023 at 2:29 PM