Can read, but not delete fault DTC codes

1. sri_130 Frequent Poster Joined: Apr 2012 Doyncaster Posts: 783

   #1 10th August 2018, 12:58

   Anyone had this issue?
   My OBD2 scanner thing, used to work as normal. But now, it can read the codes, says it's erased them, but it hasn't. Ignition off/on again, they are still there. I know I've remedied at least one of the codes as well! FFS.
   
   I bought an Elm327 cable, but struggling to get that to connect at all, to even read codes using scantool, despite it showing as connected and correct drivers on the laptop.
2. Chipwizards Frequent Poster Joined: Nov 2009 Posts: 576

   #2 10th August 2018, 21:53

   Are the ignition and battery power wires to the ECU connected exactly as stock?
   
   If not, then the 'deleted' codes, which are only deleted in RAM, don't get written out of the non-volatile EEPROM where codes are more permanently stored. So when you power it back up and the codes are read back from the EEPROM they are still there.
   
   Data (codes, adaptions etc) are written from RAM during the 'shutdown' phase after they key is turned off, which typically lasts about ten seconds.
3. sri_130 Frequent Poster Joined: Apr 2012 Doyncaster Posts: 783

   #3 12th August 2018, 09:35

   Quote:

   Originally Posted by Chipwizards Are the ignition and battery power wires to the ECU connected exactly as stock? If not, then the 'deleted' codes, which are only deleted in RAM, don't get written out of the non-volatile EEPROM where codes are more permanently stored. So when you power it back up and the codes are read back from the EEPROM they are still there. Data (codes, adaptions etc) are written from RAM during the 'shutdown' phase after they key is turned off, which typically lasts about ten seconds.

   Same as it always has been Wayne.
   I'll try another reader.
   If not, will have to ask you to delete them when I come back