Posted 5/11/2014 14:06 (#3863913 - in reply to #3863027) Subject: RE: Challenger MT645C Code E3521
I would take the cover off where the DEF dosing module is and unhook the wiring harness from the module. If DEF comes out of the connector, then you have a bad module. I would replace the wiring harness also at the same time. DEF will wick up the wiring harness and it can get as far as the ECU of the tractor. That is where I would start.
Challenger MT645C Code E3521
