In their wisdom, Genie/Deutz threw a curve in their DEF header arrangement. Story starts with a bad DEF temp sensor; NA as a service part. Have to replace entire header (seems unnecessary). Ordered replacement and find a revision/update. Different hole size in the bottle. Can't use it. Can't get a new bottle. Found a NIB header with an almost identical PN. Seller says it's one rev back, but is built the same. Numbers below. Any comments on compatibility? Machine Model: GTH1056 Machine SN: GTH10E-13283 Original PN on header: 0460-6710 2002351-00 20 W 35 Source has a 0460- 5 710 (this is not the entire header number, so a little confusing. This is the level sensor only, a component of the header ass'y) Ordered a current rev header from two sources and neither interchanged. One said they contacted Genie for help and only was told "obsolete". Electrically, the change was only to lose a module where two sensor wires (has to be temp and level) merged and allowed a harness connection point. The update seems compatible with the harness plug. I would like to know if the previous iteration would work.
Ok, so can anyone school me a bit on CANBUS? This DEF header has a 4 pin connection. Diagrams I find show a Gnd, B+, CAN Hi and CAN Lo. Roughly 2.5V above and below Gnd. A DVM will check this I am thinking. My question really is to determine how and why the ECU will not read actual temp in the tank while showing a 100% fill level. If the signal was completely missing, could that explain the extreme reading? I am not full (not 100% anyway) but like the NTC thermistor, does the R value of a magnetic level gauge (reed switches) go high when full, or low? If it were also high, I could see a problem if there was an open circuit in the harness between the DEF sensor and the ECU. That would sort of mimic a high R value. I think.
No B+ available at the DEF header. Problem resolved. Now pumping DEF all over the floor due to missing hose. Apparently the system was disabled at some point. Case closed on this issue.