PROBLEM | POSSIBLE CAUSES | SOLUTIONS & TEST POINTS |
| The car's battery may be low or dead | Connect a better charger to see if you can get communication to any of the Control Modules |
There is no power or voltage to the Control Units or the Scanner. | Ensure the Ignition Switch key is in the on position; otherwise, the entire system might not get the voltage it needs to communicate.
| |
Broken, short-circuited, dirty or corroded Control Unit harness connectors causing bad contacts. | A factory scanner dedicated to the car brand is always recommended. | |
The scanner is not compatible or does not have the correct communication protocol to talk to the Control Units | A factory scanner dedicated to the car brand is On BMWs from 1995-2001 you have to scan through the Round 20 Pin connector under the hood, if there isn't one, connect through the regular OBD2 under the dash. It’s always recommended. | |
Are you using the correct diagnostic connector? (BMW Only) | On BMWs from 1995-2001, you have to scan through the Round 20 Pin connector under the hood, if there isn't one, connect through the regular OBD2 under the dash. | |
Are there other damaged electronic modules in the car? | If you have other electronic issues, such as a bad ABS, TCM, or Air Bag modules, it can break the communication line. Try disconnecting one module at a time, and re-test for scanner communication. | |
The car's Immobilizer "Drive-Block" is activated (Porsche 993 models) | Disable the "drive-block" system by pressing on the key fob button. This will enable communication to the DME (See our YouTube video). |
| WARNING Some of the testing procedures described in this guide could be dangerous if done improperly. We recommend that they are performed by an ASE certified mechanic |
| DOWNLOAD FULL PDF Click the link to get access to the complete troubleshooting guide: http://bit.ly/34JezNP |