S/N: RKB01316 Machine is throwing a bunch of codes relating to the def pump. I troubleshot 3862-5 due to its latest occurrence and highest count. Wiring all checked out. When I took off the electrical connector on the def pump, there was water and possibly def coming out from behind the pins in the pump. With that, I changed out the pump and the same codes are active. I was going to do a def dosing system verification test, but ET wont allow it due to the active codes. Any suggestions help.
No Active Codes then.?
All of the same active codes are still present. I'm wondering if the harness is contaminated, causing all the codes. Is it worth trying to pull pins out of the connector to check? Or just install a new harness?
I’d be taking a good look at the harness for any obvious damage, or indeed checking continuity, before shelling out for a new one that may or may not fix the problem.
Continuity and the harness are good. The connector for the def pump looks like it has crystallized def on it. I don’t know how to de-pin that certain connector. If that all checks out, what else could it be? The DCU?
You need one of the Tirr 4 experts to comment on that.
I don't know anything about CAT (their DEF systems should be the same as everyone else) , however, if the connector has DEF fluid migrating into it from the DCU side, then the DEF fluid could have migrated down into the wiring of the harness (between the wire strands and the the wire insulation), corroding the wire. Just because it ohms well doesn't mean it can carry a load. All you need for a good ohm reading is for 1 wire strand to be complete, even if the rest were open. Based on the code (current below normal), I would be suspecting high resistance somewhere in the harness since you replaced the pump.
If you had def in the connector, change the PETU (DEF module) harness. The DEF fluid will wick through the wires and cause all kinds of issues as mg2361 has already stated.
I replaced the harness and the codes are still present. Is there a certain test or calibration I need to complete for it to clear the codes?
I was able to see that the pump created pressure up to around 130psi and it did purge the lines, so everything appears to be working properly. Cat is coming out on Monday to do warranty work on another machine of mine. I will see if they can clear the codes out.
Yes you need to run an after treatment system functional test.