DTC U1301 / Speedo and Tach Randomly Die

[Dr. Dolittle]

I was on day 5 of my trip last week. Bike had been running flawlessly with the 30K service done the week before and all fresh fluids. Running about 70MPH on I-24 just outside Chattanooga, the speedo and tach needles both went to zero for about a second along with illumination of the red key (check engine) and the red battery icon. Everything immediately returned to normal and the engine never missed a beat throughout this event. This would repeat itself at random times the rest of the day.

Pulled the codes and P, S, SP, and T all display a U1301 = ECM serial data high. P also displayed PN 32933-08.

I was passing right by the dealer I purchased the bike from on the way home so I stopped in for them to take a look. After about 2 hours they said they would have to keep the bike overnight for further troubleshooting. Since my wife was gone and I had no way to get home, I declined their offer and rode the 45 minutes to my house.

Did my own troubleshooting yesterday. Discovered the battery negative screw was about 1/4 turn short of being fully tight. Fixed that. After seeing it mentioned in a variety of places on the internet, including this forum, I also used some electrical contact cleaner and dielectric grease on the plug on the side of the Throttle Control Actuator.

Cleared all the codes and wouldn't you know, it happened again as soon as I started the engine.

I cannot make this happen no matter how much I bounce the bike around and wiggle every wire I can get my fingers on.

Any ideas what this could be and what I should try next?

 

[Breeze3at]

My buddies '07 did the same thing several times last September. I don't remember what he said the codes were. He pulled and cleaned the speed sensor. It did it a few more times, then stopped doing it. It has not done it since October, and he has no clue what it was. His bike was right at 30K also.

 

[Dr. Dolittle]

My buddies '07 did the same thing several times last September. I don't remember what he said the codes were. He pulled and cleaned the speed sensor. It did it a few more times, then stopped doing it. It has not done it since October, and he has no clue what it was. His bike was right at 30K also.

I've read several threads that mention the VSS, vehicle speed sensor. But they all also complained about things like the turn signals not self cancelling and the cruise control not engaging.

Neither of these apply to what's happening to my bike.

I hate to dig in there and clean or replace that bugger if I don't have to!

 

[Jack Klarich]

I have a question about the age and charge on the battery? This happened on my 97 FLHT an early warning of a shorted battery

 

[STEVE07]

We had a member a while back that had this problem and as I recall it turned out to be a bad splice in the factory harness that in time started to come undone not sending enough voltage to the speedometer and tach. I believe it is the grey/blue wire.Check for voltage at the back of the gauges.

 

[Dr. Dolittle]

I have a question about the age and charge on the battery? This happened on my 97 FLHT an early warning of a shorted battery

Battery is less than a year old - I will load test it tomorrow to be sure it's still good.

We had a member a while back that had this problem and as I recall it turned out to be a bad splice in the factory harness that in time started to come undone not sending enough voltage to the speedometer and tach. I believe it is the grey/blue wire.Check for voltage at the back of the gauges.

Is the splice something that is already there? Because I haven't spliced anything into the harness! I will add the gauge voltage test to my list of things to do.

 

[dbmg]

Hey Doc,
This might be a long shot but do you have a security system on your bike? Maybe change battery in remote and see what happens.....

 

[Hoople]

If your bike is a FLHX or FLHXI check 16 position black Molex Connector 1B-1A (especially Pin 13- Light Green/Violet wire) for water entry or oxidation.

Connector location is Inner fairing - right radio support bracket. There are a few others, but that one is higher on the list.

 

[Dr. Dolittle]

Hey Doc,
This might be a long shot but do you have a security system on your bike? Maybe change battery in remote and see what happens.....

Nope, no security.

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If your bike is a FLHX or FLHXI check 16 position black Molex Connector 1B-1A (especially Pin 13- Light Green/Violet wire) for water entry or oxidation.

Connector location is Inner fairing - right radio support bracket. There are a few others, but that one is higher on the list.

Thanks - I was going to pull the outer fairing to check the voltage at the gauges so I should be able to get a look at this item also.

 

[Dr. Dolittle]

We had a member a while back that had this problem and as I recall it turned out to be a bad splice in the factory harness that in time started to come undone not sending enough voltage to the speedometer and tach. I believe it is the grey/blue wire.Check for voltage at the back of the gauges.

Voltage at the back of the gauges is normal.

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If your bike is a FLHX or FLHXI check 16 position black Molex Connector 1B-1A (especially Pin 13- Light Green/Violet wire) for water entry or oxidation.

Connector location is Inner fairing - right radio support bracket. There are a few others, but that one is higher on the list.

Didn't see any signs of water entry or oxidation. I went ahead and applied electrical contact cleaner and dielectric grease to the entire connector.

Did the same thing to the ECM connector, the TCA connector, and the connectors on the back of the individual gauges.

Also, the battery load tested fine, only dropping to 10.5v after 15 seconds.

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I will clear the codes again, cross my fingers, and go for a ride in the morning.