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Discussion Starter · #1 ·
So, before I start pulling the bike apart to figure this out, thought I would post here for some help with a 2014 DCT.

Background (probably important) - Had major back surgery in April and literally laid in bed for three months. After that moved around VERY slowly for a couple more months. Had one of my buddies come out and ride the CTX every three or so weeks until he fell off his bicycle and cracked three ribs. Sucks getting older, but I digress. So finally got out to start the bike and discovered the Earth-X lithium battery wouldn't crank the bike. FYI - Earth-X batteries don't lose voltage like a lead-acid, they lose amperage. It still measured 13.3 when I bought the new one. When I pulled the seat to check out the battery issue I discovered a pile of dog hair. Possible my 95 lb lab decided to stuff his dog hair under the seat but I'm going to go with mouse. Now have a poison trap zip tied under the seat and a Victor mouse trap near each tire.

Problem - When we all start our DCT bikes there is a motor (think it is the ABS pump) that runs as soon as you turn the Ignition to On. I wait the 3 to 4 seconds for the motor to turn off and then start the bike. When I went to install the new battery I installed the Pos cable and as soon as I touched the Neg cable to the terminal, the motor started and it ran and ran. Remove the Neg and I check and the key is Off. I remove the key and same thing. Time it and the motor ran for 15 seconds and no sign of turning off. WTH? I pull fuses until the motor stops and it's the 30 Amp ABS M fuse. Looking around carefully I find no sign of mouse damage. Having spent almost $1K total repairing mouse damage to electrical and fuel line damage on vehicles I know what it looks like. I live on a farm and have had a couple of heart to heart talks with my cats about stepping up their game.

Anyway, anyone have any ideas (guesses accepted) on what the problem might be?

Steve
 

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Are you able to start the engine?
The diagnosis of the ABS system is described in section 20 of the Service Manual .
The ABS modulator is powered directly from battery. But according to the diagram inside of the modulator there is a Power Supply Relay probably turned on by the ignition switch. It is possible that the Power Supply Relay is on which would indicate a malfunction of the modulator.
If there is no DTC, it is difficult to know what is causing the failure. Too much guesswork. We don't know what type of Power Supply Relay this is. Is it electro-mechanical or solid state relay?
If you can start the engine, let it run for a while until it reaches normal temperature. Try it a couple of times.
 

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Discussion Starter · #3 ·
Haven't tried to start the engine as that motor is supposed to shut off after a few seconds and didnt want the engine running with that continuing to run. Like the starter it probably isnt designed for continuous operation.
 

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You don't have much choice at this point. The ABS pump runs until the brake fluid pressure in the system reaches the intended level. The ABS pump motor is internally controlled. Let the engine run for a while so you can count on some kind of miracle or... you have to replace the modulator. We only know about the problem as much as you tell us.
 

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Discussion Starter · #5 ·
Many years ago i worked in an Army R&D facility and one of the department heads had a sign on the wall that said Hope Is Not A Plan.

There's two problems - why does the ABS pump come on when the key is Off and why is the pump not building pressure or the sensor is not detecting it. I think im going to pull the tank and check for mouse damage first.
 

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You don't believe in hopes, rightly so. It is always a good idea to check for mouse damage. But this is not the case.
The operation of the ABS pump is controlled by an internal switch circuit (relay). The only signals from outside come from the speed sensors on the wheels. Briefly it looks like the ABS modulator malfunction. Additionally, you can check if the brake fluid flow through the modulator is ensured - if the brakes work without ABS.
 

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Discussion Starter · #7 ·
Should be able to do some checking of the ABS modulator, hopefully this week. Thanks.

Interesting, when looking to see how much the part costs, got this:


So I'll check and see if that part was replaced as part of the recall.
 

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Many years ago i worked in an Army R&D facility and one of the department heads had a sign on the wall that said Hope Is Not A Plan.
There's two problems - why does the ABS pump come on when the key is Off and why is the pump not building pressure or the sensor is not detecting it. I think im going to pull the tank and check for mouse damage first.
See ABS diagram page 20-3 of the service manual. It appears the ABS modulator has two power circuits going to it. Fuse # 5 (ABS M) 30 amp to power the pump running unswitched straight from the Batt through the fuse box to the Modulator and fuse #4 (ABS Main) 7.5 amp controlled by the Ing switch used as the control voltage for the relay. When testing the circuits with the key off I take a test light and clamp it to the Batt neg lug and test the 30 amp pump fuse and it lights up so this circuit is live with key off but when I test the 7.5 amp fuse with key off it has no power or no control voltage sent to the modulator. I assume the 30 amp pump circuit is always live and controlled by the relay that sends this power to the ground wire attached to the modulator to complete the circuit and run the pump.
If fuse #4 is dead with the key off and the pump is running possibly the relay is stuck latched closed or possibly the wire harness is damaged and providing a ground for the pump to run independent of control. Shade tree mechanic here, just me guessing.
http://www.greenknights36.com/html/files/Pictures/Temp/ServiceManual.pdf
Abs System Diagram - Honda CTX700N/ND Service Manual [Page 485] | ManualsLib
 

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Discussion Starter · #11 ·
Great info. Thanks. Buried in other things right now so it will be a while before I get back to this.

Happy New Year everyone.
 
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