BigDogBro1
Made in the USA
Hi Guys,
Well I started to get my bike ready to go this season and after installing the battery (Interstate Pro on Battery Tender all winter) I go and turn ON the key and PRESS RUN and the relay that feeds the 12 volts to the fuel pump, O2 sensors and other related EFI components starts to chatter ON/OFF at a VERY fast rate (almost like a buzzer).
After doing some diagnosis, running test jumpers and doing voltage checks, I find that the S&S EFI box is the problem. The wiring diagram shows that the relay power passes thru the EFI box but in reality there must be some signal conditioning electronics to drive the RELAY in the path which went bad.
I happened to have a new UNLOCKED EFI box as a backup. Although it was not yet loaded with any EFI MAP box file I figured I would still try it. Long story short it got the bike back to a key ON / RUN button fuel pump run for 2 seconds / then engine crank MODE.
I loaded the new EFI S&S UNLOCKED BOX file with "BDM_Off_road_calibration_C281_unlocked.box" with help from Tom "Groundpounder". The maps will have to go thru a LEARN time and I may need to MERGE the maps once but so far (no test ride yet) things are back to a better outlook for the season.
My bike engine is stock except for the V&H Big Radius pipes.
Hope this helps any of you out there that may get the same problem.
UPDATE: 4-22-15
I bench test powered (pin 10 is Ground and pin 13 is +12 volts) my old 55-5029 ECM and see if would talk to the computer thru the 9-pin serial port, NO LUCK. The Protune2 software would not recognize the ECM on any port. I opened up the ECM module and removed the PCB to check for any reason for the failure. The only obvious thing I saw was a spot on one of the Fairchild memory chips that looked like it got HOT and burnt the conformal coating on one corner.
I also spoke with Tom Hampton from S&S and he mentioned that the battery connections should be done by attaching the POSITIVE terminal cables FIRST and then the negative terminal cables. He claims it has something to do with the way the ECU controls its ground referenced control signals. In my opinion that Delphi made ECU should be bullet proof in regards to the input +12v electrical power conditioning. These systems should be designed internally to protect any sequence of power connection. Normally a electronic computer device designed for automotive use has been designed to survive the harsh electrical environment it is to be placed in. Also I don't recall any mention in the Bigdog Service Manual about battery cable connection preferences. And to add insult to injury S&S wants $550+ dollars for the USB version of the ECU replacement. As our EFI bikes continue to age I have been noticing more and more problems with these Delphi/S&S ECU EFI controllers...is this the new EHC?
Ride Safe!
BDB1
Well I started to get my bike ready to go this season and after installing the battery (Interstate Pro on Battery Tender all winter) I go and turn ON the key and PRESS RUN and the relay that feeds the 12 volts to the fuel pump, O2 sensors and other related EFI components starts to chatter ON/OFF at a VERY fast rate (almost like a buzzer).
After doing some diagnosis, running test jumpers and doing voltage checks, I find that the S&S EFI box is the problem. The wiring diagram shows that the relay power passes thru the EFI box but in reality there must be some signal conditioning electronics to drive the RELAY in the path which went bad.
I happened to have a new UNLOCKED EFI box as a backup. Although it was not yet loaded with any EFI MAP box file I figured I would still try it. Long story short it got the bike back to a key ON / RUN button fuel pump run for 2 seconds / then engine crank MODE.
I loaded the new EFI S&S UNLOCKED BOX file with "BDM_Off_road_calibration_C281_unlocked.box" with help from Tom "Groundpounder". The maps will have to go thru a LEARN time and I may need to MERGE the maps once but so far (no test ride yet) things are back to a better outlook for the season.
My bike engine is stock except for the V&H Big Radius pipes.
Hope this helps any of you out there that may get the same problem.
UPDATE: 4-22-15
I bench test powered (pin 10 is Ground and pin 13 is +12 volts) my old 55-5029 ECM and see if would talk to the computer thru the 9-pin serial port, NO LUCK. The Protune2 software would not recognize the ECM on any port. I opened up the ECM module and removed the PCB to check for any reason for the failure. The only obvious thing I saw was a spot on one of the Fairchild memory chips that looked like it got HOT and burnt the conformal coating on one corner.
I also spoke with Tom Hampton from S&S and he mentioned that the battery connections should be done by attaching the POSITIVE terminal cables FIRST and then the negative terminal cables. He claims it has something to do with the way the ECU controls its ground referenced control signals. In my opinion that Delphi made ECU should be bullet proof in regards to the input +12v electrical power conditioning. These systems should be designed internally to protect any sequence of power connection. Normally a electronic computer device designed for automotive use has been designed to survive the harsh electrical environment it is to be placed in. Also I don't recall any mention in the Bigdog Service Manual about battery cable connection preferences. And to add insult to injury S&S wants $550+ dollars for the USB version of the ECU replacement. As our EFI bikes continue to age I have been noticing more and more problems with these Delphi/S&S ECU EFI controllers...is this the new EHC?
Ride Safe!
BDB1
Last edited:
