Why did programming fail?

Common causes include:

• The locomotive is on MAIN output A instead of PROG output B.
• The programming track is not isolated.
• Dirty wheels or poor pickup.
• The decoder does not support CV readback.
• Track power or programming mode is not set correctly.
• The locomotive has a stay-alive capacitor affecting programming.
• The wrong protocol/connection mode is being used in Engine Driver.

Try cleaning wheels, checking wiring, using the dedicated programming output, and testing with a known-good decoder.

Imported from: DCC-EX CSB1 and Engine Driver FAQs