2005 GTX SC TOPS, fuel pump and idle air bypass cycle without DESS

[Hokiebob]

An update from earlier post. Without DESS on post, all three in title cycle every 5 sec or so-obviously will kill battery. When I install the DESS, things appear normal with no codes and runs well. I’ve cleaned all ground connections and am at a loss. What could it be other than mpem-its bizarre. Removing one of the small grounds from the battery post turns them off, along with disconnecting mpem1 connector or large 30A main fuse. Thx for any suggestions

 

[shelford777]

An update from earlier post. Without DESS on post, all three in title cycle every 5 sec or so-obviously will kill battery. When I install the DESS, things appear normal with no codes and runs well. I’ve cleaned all ground connections and am at a loss. What could it be other than mpem-its bizarre. Removing one of the small grounds from the battery post turns them off, along with disconnecting mpem1 connector or large 30A main fuse. Thx for any suggestions

I’m having the same exact problem. But now the display lights up and beeps with out the dess plugged in. When I put the Dess on it will not work either.

 

[Jpse]

I have all these problems on a 06 gtx , look for thread 2006 gtx cluster stays on the fuel pump is on and beeps three times as though the key is on dess post when it is not
I changed mpem, rectifier, dess post, no fix plugged in an ecm with its key( yet from e newer ski without mpem) but ski was finally off put key on post it double beeped and powered up so I concluded it was the ecm and wasn’t going to pay 800$ for an ecm bought a auto marine power disconnect and mounted in glove box 8$

 

[Scriz]

Had the same issue with my 2004 GTX. Changed everything, to include the wiring harness, before swapping out a new ECU. ECU fixed it. I also used a switch in the glove box for awhile before I found a decently priced ECU.

 

[Jpse]

Thanks for info been revisiting it and checked eBay and saved search for ecm gonna wait for a reasonably priced one also