[HMcGee]

No spark on my Sportsman, I replaced the Stator and Crank Position Sensor not too long ago and it ran great for a while.
I checked the stator and CPS and they are still in spec, I checked the CPS gap and that is OK. Tried to disconnect the black wire from the key and still no spark.
Tested the ignition coil and it measures to spec.

I see the ignition coil is connected between the ECU and the PDM. How do I determine which is causing the issue?
Is there something else I should be looking at? The speedometer comes on and indicates OK and the starter turns, but no spark. I thought I remembered I could hear the fuel pump click on when I turned the key, but I don't hear that now. (I may be mistaken on this one.)

I see ModuleMasters rebuilds the PDM, I would like to somehow determine if that is the problem somehow before pulling it and sending it off.

Thanks for any ideas in advance,

 

[latebird]

You need 12v on pin 31 of the ECU 24/7 and 12v on the red/wht wire on pin 34 when the key is on then disconnect the black wire from pin 51 of the ECU and see if spark is restored - if you have the voltage on those wires and the black wire disconnected and no spark, take it to a dealer and have them run the diagnostic software on it - if you are missing a voltage at the ECU, let me know which wire does not have voltage.

 

[HMcGee]

You need 12v on pin 31 of the ECU 24/7 and 12v on the red/wht wire on pin 34 when the key is on then disconnect the black wire from pin 51 of the ECU and see if spark is restored - if you have the voltage on those wires and the black wire disconnected and no spark, take it to a dealer and have them run the diagnostic software on it - if you are missing a voltage at the ECU, let me know which wire does not have voltage.

How do I test to those pins? Do I unbolt the ECU, unplug the Connector, and test at the connector pin while unplugged from the ECU? Do I need to pull the ECU where I can see it and use a pointed tester at the wire?

 

[HMcGee]

You need 12v on pin 31 of the ECU 24/7 and 12v on the red/wht wire on pin 34 when the key is on then disconnect the black wire from pin 51 of the ECU and see if spark is restored - if you have the voltage on those wires and the black wire disconnected and no spark, take it to a dealer and have them run the diagnostic software on it - if you are missing a voltage at the ECU, let me know which wire does not have voltage.

I went ahead and pulled the ECU plug and tested at the plug. I have 7.77VDC at pin 31 24/7 and 12.59 with the key on at 34.

 

[HMcGee]

I can see that Pin 31 ties back to a RD splice then another RD/BK splice that ties to the SSCB#1 Pin S, which is the ECU Relay point off of the PDM. I am assuming this is an indicator that the PDM is bad since it is only at 7.77VDC?

 

[Vern220711]

I have an 05 sportsman 500 and it’s turning over good. I’ve drained the oil and replaced it, rebuilt the carb and cleaned thoroughly, getting spark but still will not start I sprayed starting fluid into carb through intake and it hit once but still did not start what else can I do to get this thing going

 

[HMcGee]

Any other ideas on why I only have 7.77 VDC on pin 31? Should I go ahead and send the PDM in for a rebuild?

Thanks,

 

[latebird]

I can see that Pin 31 ties back to a RD splice then another RD/BK splice that ties to the SSCB#1 Pin S, which is the ECU Relay point off of the PDM. I am assuming this is an indicator that the PDM is bad since it is only at 7.77VDC?

Sorry for the delay, I had a network problem to address - just got things back up and running

To test - jump 12v to the the red wire at pin 31 - if that fixes it, then the SSCB is the problem component, but you may have multiple problems if the SSCB is defective.

 

[latebird]

I have an 05 sportsman 500 and it’s turning over good. I’ve drained the oil and replaced it, rebuilt the carb and cleaned thoroughly, getting spark but still will not start I sprayed starting fluid into carb through intake and it hit once but still did not start what else can I do to get this thing going

Check the valve adjustment

 

[HMcGee]

Sorry for the delay, I had a network problem to address - just got things back up and running

To test - jump 12v to the the red wire at pin 31 - if that fixes it, then the SSCB is the problem component, but you may have multiple problems if the SSCB is defective.

In general how would I make this "jumper" and have the module plugged in? Use a trailer wire splice and piece of wire between the two wires? Same for the "disconnect the black wire" note, how is that done usually? I am curious because these are all factory cables with connectors on the end that are not easy to disconnect and jump.

Thanks,

 

[latebird]

I have special tool to remove the pins to disconnect wires or remove wires from the connectors - for the shade tree mechanic, you cut the wire and splice it back together.

A trailer wire connector? You are talking about the POS Scotch lock connectors? I suppose that would work, but for testing, I just pierce the wire insulation with a straight pin and use a test lead with an alligator clip to connect between a power source and the wire in question.

 

[HMcGee]

I jumped 31 and got some clicking like it used to , like the fuel pump or something, but no start.

 

[latebird]

Without being able to connect it to diagnostic software, best guess is a faulty SSCB - part number 4011657 it is in essence a $545 fuse, but is is also the rec/reg for charging the battery - it controls the fuel pump, lights and ignition and tries to protect the ECU - to get it fixed without buying parts that are not needed, take it to a dealer who can diagnose and fix it - yes you have to pay for the labor, but you bought the EFI and the technology that goes with it and it takes technology to correct it.

It would be a real pisser to buy an SSCB and find out it works the same as the old one, then buy a CPU for $505 and ultimately find out it was a poor connection in one of the splices in the wiring harness that was the root of the problem.

 

[HMcGee]

Thanks for the advice latebird, are these splices hidden throughout the wiring harness, are they labeled in any way? I will keep working the issue and post a resolution once I come to one.

 

[latebird]

Some are visible and accessible and some are buried - you simply need to remove all the plastic to get to them

 

[HMcGee]

I went ahead and sent the SSCB and they found no issues, I went ahead and had it rebuilt for good measure. No change on the bike since reinstalled though. I re-checked pin 31, with the plug unplugged I get 7VDC key off run switch off. With the plug plugged into the ECU I get 0 VDC at pin 31. So I have no voltage at pin 31. If I jump 12VDC to the pin 31 wire I can hear the fuel pump (I think, like it used to) click on but the bike still will not start. Where is pin 31 supposed to be getting its voltage from? Pin S of the SSCB? That is the ECU Relay on the SSCB which somehow ties back to the KAP input on the ECU?

Thanks,

 

[latebird]

Pin 1 and 31 gets voltage from splice #1 - splice #1 gets it's voltage from rd/bk splice (wire 109) - the red/blk splice gets voltage from wire 64 on pin S of plug #1 of the SSCB - again, it points to either the SSCB or the wiring as a problem.

Now the red/blk splice supplies 12v to the red/blk wire of the fuel injector - if you have 12v on the red/blk wire of the injector and only 7v on pin one and pin 31 of the ECU with the key on (there should be no voltage to either pin 1 or 31 with the key off) - the problem would appear to be the splice.

The dealers have a diagnostic software for troubleshooting EFI machines - the complexity is overwhelming for the average owner. It's akin to using a programmable logic control to make a lawn mower run.

However, if you persist and are diligent, you might stumble upon or discover the cause of the problem

 

[HMcGee]

Will keep at it, I am trying to find a local dealer or repair shop that can run diagnostics. I am concerned that the diagnostics device requires 12VDC from the same splice based on the wiring diagram. I do not have 12VDC at the diagnostic plug right now. Looking at the SSCB diagram, and reading the service manual, the KAP EFI Input Controls the ECU Relay Output. I do not think I have 12VDC right at pin S. I am assuming something is wrong with the KAP EFI input or an overload on pin S is shutting the IPS down.

 

[latebird]

You are correct - there needs to be 12v on the red wire on pin A of the diagnostic plug.

Following the circuit, you should have 12v on SSCB1 pin H from the key switch and if the SSCB is functioning correctly, 12v on SSCB1 pin S - pin S supplies 12v to the red/blk splice

 

[HMcGee]

Thanks,

I will do some more testing this afternoon. As a note, the diagram I have shows pin H coming straight from the battery tied to the starter solenoid. It is hot all the time. I do have 12VDC at that point.
Maybe I can disconnect Pin J1-S at the SSCB and see if it fires up, then start adding everything back one by one to see what causes it to shutdown. That would at least tell me that it is trying to come on and that the ECU Relay Control and KAP EFI and Run Input are OK.