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Discussion Starter #1
Hi there, I'm an auto/diesel technician diagnosing a crank, no start on an 06 Vrod. I specialize in electrical/electronic diagnostics, but bikes are new to me.
The bike was on a trip, rider stopped for fuel and wouldn't restart, only cranks. Another technician looked at it and diagnosed an IAC motor. Replaced component. Concern not resolved.

Upon my receiving the bike, I have determined the system relay is not receiving a ground from the ECM to energize the relay.
At the relay:
-White/Black wire (86) from hand control switch has battery voltage when switched on and 0V when switched off. (y)
-Blue/Gray wire (30) has constant power from the battery. (y)
-Green/Orange wire (85) never receives ground from the PCM to complete the circuit. (n)
-Yellow/Green wire (87) does not (cannot) output power to the fuel pump, injectors, or coils resulting in crank, no start concern.

If I connect a jumper wire from the battery ground to the Green/Orange wire (85) at the relay, the bike starts. It will not idle on it's own because the IAC motor is completely closed. It will idle if you manually hold the throttle open a little bit.

Battery was replaced, all fuses are good. Swapped the System relay and the starter relay. They both function. I used a DVOM to ensure the Green/Orange wire between the module and the relay is OK, it is not open or grounded and only drops 2 mV. I used a scope to check CKP, VSS, and TPS. They're all outputting a good signal. Used the factory manuals to troubleshoot the ECM and I keep coming to the conclusion of replace and reprogram the ECM.

ECM failure is very uncommon in the auto/diesel world. Before I condemn it I wanted to ask if there could possibly be an input that I am overlooking causing the ECM to not provide ground. Per the manual, a Bank Angle Sensor failure would result in the starter disabled. Any ideas?
 

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Hi there, I'm an auto/diesel technician diagnosing a crank, no start on an 06 Vrod. I specialize in electrical/electronic diagnostics, but bikes are new to me.
The bike was on a trip, rider stopped for fuel and wouldn't restart, only cranks. Another technician looked at it and diagnosed an IAC motor. Replaced component. Concern not resolved.

Upon my receiving the bike, I have determined the system relay is not receiving a ground from the ECM to energize the relay.
At the relay:
-White/Black wire (86) from hand control switch has battery voltage when switched on and 0V when switched off. (y)
-Blue/Gray wire (30) has constant power from the battery. (y)
-Green/Orange wire (85) never receives ground from the PCM to complete the circuit. (n)
-Yellow/Green wire (87) does not (cannot) output power to the fuel pump, injectors, or coils resulting in crank, no start concern.

If I connect a jumper wire from the battery ground to the Green/Orange wire (85) at the relay, the bike starts. It will not idle on it's own because the IAC motor is completely closed. It will idle if you manually hold the throttle open a little bit.

Battery was replaced, all fuses are good. Swapped the System relay and the starter relay. They both function. I used a DVOM to ensure the Green/Orange wire between the module and the relay is OK, it is not open or grounded and only drops 2 mV. I used a scope to check CKP, VSS, and TPS. They're all outputting a good signal. Used the factory manuals to troubleshoot the ECM and I keep coming to the conclusion of replace and reprogram the ECM.

ECM failure is very uncommon in the auto/diesel world. Before I condemn it I wanted to ask if there could possibly be an input that I am overlooking causing the ECM to not provide ground. Per the manual, a Bank Angle Sensor failure would result in the starter disabled. Any ideas?
Green/orange wire only receives ground signal from ECM for 2secs when ign is turned on just to prime fuel line, then will only show a ground when the motor cranks and the ECM receives a signal from the crank sensor. It is possible that you have a faulty crank sensor so I would look thre first, but it has been known for the ECM to fail not giving this ground signal. It is not common but I have heard of some failures.
 

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Discussion Starter #4
The CKP has been replaced, although it was validated with the scope. No change. Per the manual the TSSM functionality disables the starter so I ruled that out on those grounds. HD has given a $365 price on the replacement ECM and a $50 labor charge to marry the modules. But I am waiting on a two week arrival time for parts. I'll keep ya posted.
 
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