Alarm output low on bike with no security?

[chester1957]

A friends 02 Fatboy started flashing the 4 ways 3-5 times a few seconds after the key is turned on.
I found in the manual how to check this with the turn signal buttons.
It showed a code 31 alarm output low. This bike doesn't have security installed on it. I followed the manual stating the lt/grn-brn wire should either be open or grounded, I checked this wire and it is neither open or grounded.
I read where a couple of people pulled the connectors and cleaned them and the problem went away. These are sealed connectors and found no problems with them, others with this problem, never came back online to report how they fixed it.
Any thoughts as how to solve this problem? I'd hate to spend the money for a new TSM module and not have it fix the problem.
I've tried clearing the code with the turn signal buttons, but it comes right back.

 

[Hoople]

This bike does Not have Factory security.

Where is this Lt/green-brn wire coming from that you are checking. One end goes to what? The other end goes to what?
If it is not open or grounded then what it is purpose if the bike does not have factory security.

 

[chester1957]

One end is at the TSM the other is at the connector where the ECM of a FI bike would be. As it is a carbed bike there is no ECM, just a couple of modules mounted on the fender where the ECM would be.

The only mod to the bike is the factory H-D run/turn/brake module. I have unhooked this and the problem is still there.

This bike does Not have Factory security.

Where is this Lt/green-brn wire coming from that you are checking. One end goes to what? The other end goes to what?
If it is not open or grounded then what it is purpose if the bike does not have factory security.

I believe all have the wiring, it also has the pigtail and connector for the siren under the TSM also.

 

[Hoople]

Alarm output low, to me, indicates that the alarm wire (assume siren) is shorted to ground.
I could tell you a lot more if I had the flow chart for DTC 31 along with the schematic of the turn signal module in front of me.
Any chance of uploading those pages out of the service manual.

 

[chester1957]

Alarm output low, to me, indicates that the alarm wire (assume siren) is shorted to ground.
I could tell you a lot more if I had the flow chart for DTC 31 along with the schematic of the turn signal module in front of me.
Any chance of uploading those pages out of the service manual.

Sorry I don't have a scanner. What I have found on the net, some fix it by cleaning connectors and clearing the code, others replaced the TSM and some just live with it.
I double checked the p/n on the part and it is indeed the TSM not the TSSM p/n. They only used this part for 2001 and 2002 and is a somewhat common problem.


Thanks for your time Hoop.

 

[softailhog]

Alarm output low, to me, indicates that the alarm wire (assume siren) is shorted to ground.
I could tell you a lot more if I had the flow chart for DTC 31 along with the schematic of the turn signal module in front of me.
Any chance of uploading those pages out of the service manual.

Hey Hoop, not necessarily. I had the same problem on my 02 Heritage, kept getting the 31 code. Turns out that the fuse that powers the siren (even though I don't have one) was corroded and so no B+ was present so the alarm output (to siren)is low (no voltage). The siren sounds when there is no voltage (low) and stops when there is voltage (high). Check and see if you have a fuse marked security system in the box and check to see if it's blown, then check it with a voltmeter and see if you get the battery voltage there. If you do it may be in the wiring as stated earlier but why not check the easy thing first. I would think a short would blow that fuse pretty quick.

 

[Hoople]

Hey Hoop, not necessarily. I had the same problem on my 02 Heritage, kept getting the 31 code. Turns out that the fuse that powers the siren (even though I don't have one) was corroded and so no B+ was present so the alarm output (to siren)is low (no voltage). .

You bring up a Great point. I haven't yet figured out exactly know how HD defines a "Low" or "Hi" with there DTC's since it really depends how you want to look at it. In some electronic circles a "low" is defined when a pull up resistor (a power source reference supply voltage) is pulled to ground with a short.
You still have power, but it is being pulled "low" to ground. (the pull up resistor allows shorting a power source to ground without damage)

But at the same time it also can be looked at from your view point as the power supply voltage is totally missing or "low". Yes indeed, that is also correct.

You probably nailed the OP's problem right on the head with the correct fix...

Thanks for letting me know because I really was not 100% sure how HD defined there logic levels.

 

[chester1957]

Yes, there is a fuse marked security, fuse is good and contacts are clean, first thing I checked.

 

[softailhog]

Saw this elswhere and this led me check the fuse. It explains which wires go where. Do you have the wiring diagram? And even though the fuse is good did you check each side of the fuse with a DVM to see that voltage is indeed present through the fuse?

"Possible causes:
31&32= Middle pin on siren goes low voltage to fire alarm, high voltage to stop.
If the siren responds with 3 chirps instead of 2 the siren battery is bad.
Pin A (Bn/Gy) is positive voltage downstream of the 15amp security fuse.
Pin C (Bk) is ground from pin 12 (Bk) on TSSM"

I would think you need to trace the brown/gray wire from the fuse block down to the
connector for the (not there) siren and see if it's shorted. Pin A and C refer to the pins on the siren. All the 2002 domestic and international carbed Softails have the same wiring harness according to my HD manual. Good luck, I know how frustrating this can be.

 

[91FXRS-Conv]

Sorry I don't have a scanner. What I have found on the net, some fix it by cleaning connectors and clearing the code, others replaced the TSM and some just live with it.
I double checked the p/n on the part and it is indeed the TSM not the TSSM p/n. They only used this part for 2001 and 2002 and is a somewhat common problem.


Thanks for your time Hoop.

What is the part number on the TSM? Could I trouble you to take a pic of the plug into it, showing the wiring of the plug (which wire to which corner of the plug)? I'd appreciate it, fighting similar unrelated problems...