There are a variety of reasons why a controller cannot be read, referencing the exact error code returned from the controller against the EFILive Error Codes.pdf, or the newly added [F8: Tools] -> [F8:Lookup Errors] option in the V8 Scan and Tune software provides details on the exact nature of the issue experienced.
Often errors are not caused by a 'problem' at all, some read errors occur because of ECM or Operating design features (or constraints). Design features/constraints can be summarized into the following categories:
Some manufactures have commenced implementing restrictive architecture preventing the contents of the controller from being read. These controllers do not adhere to the typical "EFILive process" for tuning supported vehicles. Customers will need to obtain a suitable base file for editing and flashing purposes. Controllers that have read restrictions in place include:
- Cummins 2010-12 CM2200A (CMD)
- Cummins 2013-15 CM2350B (CME)
- Duramax 2011-15 LML (E86A & E86B)
- GM Diesel Family B Engine 2014-15 (E47) *Note: Mapping support not available.
For some Custom Operating Systems EFILive writes tune files to non-readable memory. These tune files cannot be read out from the ECM. Custom Operating Systems that prevent the controller from being read are:
- Cummins 2006-07 CM849 (CMB) CSP5
- Cummins 2007-09 CM2100A (CMC) CSP5
- Cummins 2010-12 CM2200A (CMD) CSP5
- Cummins 2013-15 CM2350B (CME) CSP5
- Duramax 2007-10 LBZ/LMM DSP5
Traditionally when an ECM is locked it cannot be reflashed by any tuning tool until it has been unlocked. Only the original tuner was able to unlock the controller to allow it to be reflashed. While that type of locking protects a tuner's IP it also creates problems for customers when their vehicle needs to be reflashed elsewhere. If the customer is no longer able to visit the tuner's shop or the original tuner is no longer in business or the tuner simply refuses to unlock the controller then sometimes the only option is to replace the controller.
EFILive Auto-Locking uses a modified locking strategy. When an ECM is Auto-Locked all non-EFILive reflashing tools (such as GM's TechII) will be prevented from reading and flashing the controller. However EFILive's Tuning Tool will always be able to reflash the ECM. Depending on the Auto-Lock status of the file being flashed, the ECM will either remain locked or be unlocked at the completion of the flash. Auto-Locking is available on LS1B, E38, E39, E40, E54, E60, E92 & E98 controllers.
The Problem Reading a Controller knowledgebase article provides helpful tips for troubleshooting controller reading.