no communication with scan tool.
May 31, 2019 at 3:47 AM
ECM not communicating with scan tool
1999 BMW 540I
DOUGLAS COOPER
- MEMBER
- 1 POST
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KASEKENNY
- ✓ASE Certified Mechanic
- 18,907 POSTS
Hi Douglas,
There are three things that a scan tool and module need in order to communicate with it. Power and ground for the module, and a communication wire. Your vehicle uses the wire in cavity 12 and 17 to communicate with the ECM. If these wires are not intact it will not be able to talk to it.
If the ECM does not have power or ground, then it will not be online and the scan tool will not be able to communicate with it.
However, if you have power, ground, and good communication lines, then most likely the module is just defective.
Your power wire for the ECM is pin 7 and ground is 3,4, and 5.
Let me know if you have more questions or I can assist further. Thanks
https://www.2carpros.com/articles/how-to-check-wiring
There are three things that a scan tool and module need in order to communicate with it. Power and ground for the module, and a communication wire. Your vehicle uses the wire in cavity 12 and 17 to communicate with the ECM. If these wires are not intact it will not be able to talk to it.
If the ECM does not have power or ground, then it will not be online and the scan tool will not be able to communicate with it.
However, if you have power, ground, and good communication lines, then most likely the module is just defective.
Your power wire for the ECM is pin 7 and ground is 3,4, and 5.
Let me know if you have more questions or I can assist further. Thanks
https://www.2carpros.com/articles/how-to-check-wiring
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May 31, 2019 at 7:19 PM
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