The ECM gets battery power that is unregulated (other than the voltage regulator from the alternator). The ECM generates the +5V for sensors and it is regulated by the ECM.. You should not see any change in the +5 volts unless the ECM drops below somewhere between 7-10 volts, maybe lower. If you saw 5.75 volts at the sensor wire, and suspect it's the system relay, it is more then likely ECU ground is flakey. When the ECM switches on the system relay, it is essentially trying to drive one side of the coil in the relay to ground while the other side of the coil is driven from the handlebar switch. If the ECM ground is bad, it's ground could shift upwards.. It looks to be about 0.7 volts.. Check the black wire in the sub harness and follow it through the 12 pin connector all the way to a round lug that fastens to the frame in the main harness.. If you have a wiring diagram you see it.. Check the number 12 pin connector between the bike harness and the EFI harness.. Pin 12 appears to be the ground for the ECM.

 

Johnny,
Did you open the links? Boardtracker sells the manual for $48 plus shipping and the used one on eBay was $30.

edit :
I deleted the pages from the 2008 manual as they were different systems.

 

....

 

Guess it's been said. But unplug the plug on the IAT and the ECM. Make sure with a good volt/ohm meter that there is less resistance the 1 ohm for pin 1 to 7 Lt GN/7 wire and pin 2 to 26 BK/W wire. Look closely at both female and male pins and both connections are ECM and the new IAT. I am with you. It's a connection. And it might take 6 hands to pick it up. 4 for holding meter probes on wire and two to wiggle wire if that truly is the problem.

 

I live here in Canada and of course our dollar is on the low side as of late and probably staying that way for a while. A used manual might suffice if I can find one locally.

 

I'll buy the one on eBay and mail it to you. Shouldn't be anymore than 45 C.
Let me know.
Bill

 

OK, thanks again :-)

I see that Pin 28 and 10 from the ECM are grounded to Stud 2 which I have located and inspected - Grnd pin 12 ties in with ECM at pin 10 too and the instrument cluster, VS Sensor and Fuel Gauge which are all 5V I assume - I'll take another look here in the near future to see what voltage is being sent through that stud from ECM but I'm sure it's normal. I though initially that IAT sensor might be throwing an error due to too much voltage.

I have noticed just lately that although the CEL is still on constantly, it seems to pulse once every several seconds even when just the ignition is on and the motor is not running :-/ like it's cycling through something.

 

I'll post a couple of the schematics, if they are the same as the 2005 then I think there is some confusion as to which pins are the actual grounds. 10 & 28 are the power grounds that go to the Left Hand Stud. Pin 12 is the CKP ground. To check the IAT resistance disconnect the ECM at connector 78 and ohm wires 7 and 26 resistance should be between 2K and 5K ohms. Connect the ECM and disconnect the IAT and turn Ign. on, you should read 5v at IAT connector 89B. Disconnect both ends and check the connectors to make sure all the pins and sockets look even, that none are recessed so they may not be making good contact. Ohm the wires while wiggling like Ripsaw said, this may take more than one person. Check continuity to ground to make sure you don't have a rubbed spot somewhere. I don't see how the system relay could be playing a role in P0113. If your not getting DTC's for ET, MAP or TPS then I think your ground is good.

Follow the trouble shooting guide I posted earlier

 

Not sure where the confusion is if it was my stuff but I was discussing the sub harness connector not the ECM.. Pin 12 on the sub-harness connector is where the ECM gets it's ground to the frame. The rest of your stuff sounds good.. I don't know if a bad ground can cause P0113 but it can cause a higher than normal +5V reading on the meter if the meter reference is battery ground and not ECM. FWIW, Bad power or ground can cause all kind of issues.


BTW, The main harness picture you are showing is for an FLHT/FLTR bike.. I think this is an FLHR type bike.

 

My mistake, I was looking at the ECM connector 78 and pin 12 is CKP you are referencing connector 8 and 12 is the right hand ground. Looking at his picture you're right it most likely is a Road King.

The reason I said I thought the ground was good the ET Has DTC P0118 which looks to be nearly identical to P0113 .

I'll post the correct schematics and re-post the trouble shooting guide.