Remember: On a John Deere, a D1A code is a , not a scream about mechanical failure. Treat it like the electrical issue it is, and you’ll be back in the field within the hour.
Turn the key off. Open the hood.
: Diagnostic trouble codes are actively stored in this module. Cycle the hazard switch again to flash the actual multi-digit fault numbers. Decoding Real John Deere DTC Formats john deere d1a code full