Rail (625Wh) Trek rail Bosch error code 504

Kernow

E*POWAH Elite World Champion
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Jan 18, 2018
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Cornwall uk
stopped for a break and bike switched back on with a 504 error code and was in limp mode , i looked here for reasons and a fix but found nothing and it seems all reasons i could find pointed to using derestricting devices which i dont have , anyway lots posts on you tube telling me to ride for an hour without assistance with system switched on and few running the bike using a drill as in my pic to simulate riding for an hour , i was sceptical but i did this for an hour using a drill with bike in a stand as it advised and hey presto error code gone and no more limp mode ,
ive done a good 15 miles on it and so for error has not returned .
No idea still why the error popped up which is a small concern but just pleased this simple fix worked . I think ill get to a shop when i can to check for updates maybe as its never been updated since it was new in 21
iCloud Photos - Apple iCloud
 

Redders473

Active member
Jul 30, 2020
197
118
Leeds
Mine used to do it bud it can happen randomly. You can go to a shop to clear it or just ride it for an hour and it will clear itself.

It's boring AF riding it around but after an hour turn it off and then it should be cleared.
 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,606
5,098
Coquitlam, BC
Had a similar error (504) and a visit to the LBS and update seemed to fix the problem. Nothing else in the past three years.
 

Tone461

Active member
Nov 29, 2020
120
247
West Midlands
Yep, GF's cube did it quite a while ago. Luckily we weren't that far from the car. Took it to the excellent Race co and they cleared it on the laptop in a couple of minutes. Deristriction error (not), never done it since, totally random .
 

Kernow

E*POWAH Elite World Champion
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Founding Member
Jan 18, 2018
1,436
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Cornwall uk
Mine used to do it bud it can happen randomly. You can go to a shop to clear it or just ride it for an hour and it will clear itself.

It's boring AF riding it around but after an hour turn it off and then it should be cleared.
I did keep riding for over an hour , i had to to get home but it didn’t clear ,
there’s lots of conflicting remedies i read about how long you need to keep riding etc and many say you have to ride without using assistance for that hour , some say it has to be an even speed between 9and 11 mph , heaven knows at what point it actually would clear
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,577
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Weymouth
504 is probably a general code for when the system detects an anomoly...certainly that could be caused by a deresriction device but equally it could be caused by an incorrect speed sensor reading..............and that could either be due to some damage on the speed sensor cable or some restriction on the actual magnet/sensor. The latter most likely being temporary. I would check your sensor and sensor magnet and the sensor cable. Note, one very common area where the sensor cable can suffer damage is where it exits the chainstay ( assuming it is fed through the chainstay).
 

Kernow

E*POWAH Elite World Champion
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Jan 18, 2018
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Cornwall uk
504 is probably a general code for when the system detects an anomoly...certainly that could be caused by a deresriction device but equally it could be caused by an incorrect speed sensor reading..............and that could either be due to some damage on the speed sensor cable or some restriction on the actual magnet/sensor. The latter most likely being temporary. I would check your sensor and sensor magnet and the sensor cable. Note, one very common area where the sensor cable can suffer damage is where it exits the chainstay ( assuming it is fed through the chainstay).
Yes ive checked the sensor and its parts ,that is what the code is for
I did wonder if some dirt had temporarily caused a fault
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,577
5,067
Weymouth
Yes ive checked the sensor and its parts ,that is what the code is for
I did wonder if some dirt had temporarily caused a fault
I seem to remember that Trek use their own sensor rather than the Bosch one and it is dual pole (sends 2 pulses per wheel revolution) ......so might be a bit more sensitive to mud or trail debris blocking the magnet or sensor .
I had a stick pull the sensor from its holder on my bike once. I have kiox300 fitted so I get the fault code on that. I easily put the sensor back in its holder and switched back on but the fault report was still there. Cleared that with the LED Remote square button but the bike still did not work properly. Switched it off and left it for a few minutes .....then switched back on and all OK. So it seems that is the routine required.
 

antarcher

New Member
Jan 20, 2023
4
3
New Zealand
I have a 2021 rail7 that was getting random issues with the speed sensor switch so I went into and electronics store and bought a NZ$5 reed switch from the home security section of an electronics store.

Screenshot 2023-12-31 150608.png


Thought I was smug repositioning the switch for the good old crank hack to go past the speed limit but soon found out that the bosch computer tallies up data and after a while concludes that the 'wheel' isnt rotating as much as expected so throws the 504.

So I hooked up the power drill to crank as Youtube suggested. The set up fell to bits bits after about 45 mins but was enough to clear error.

Think bosch sells you the switch on wire and plug so you have to route all way through chainstay to battery for about NZD$50. I just soldered in the new reed switch (with heatshrink) so avoided all the cost and fuss. The switch even fit the mount perfectly.

The switch is a simple on/off reed so wouldnt expect it can send two pulses per rotation - and of course my speedo is reading sensibly.
 

ebikemotorrepair

New Member
Nov 10, 2023
8
4
Franklin Tennessee
stopped for a break and bike switched back on with a 504 error code and was in limp mode , i looked here for reasons and a fix but found nothing and it seems all reasons i could find pointed to using derestricting devices which i dont have , anyway lots posts on you tube telling me to ride for an hour without assistance with system switched on and few running the bike using a drill as in my pic to simulate riding for an hour , i was sceptical but i did this for an hour using a drill with bike in a stand as it advised and hey presto error code gone and no more limp mode ,
ive done a good 15 miles on it and so for error has not returned .
No idea still why the error popped up which is a small concern but just pleased this simple fix worked . I think ill get to a shop when i can to check for updates maybe as its never been updated since it was new in 21
iCloud Photos - Apple iCloud
Hi Buddy. Not sure if you have solved this problem or not but it is very likely you simply have or had the spoke magnet on the rear wheel misaligned. It isn't impossible for it to have been dirty with something that interfered with the magnetic field as well. Not likely but not impossible. In the future the dealer should be able to clear the code instead of using your drill for an hour. clever idea though. That is definitely a way that works when the speed chips are detected. Anyway hope your problem is resolved and please let us know if you ever have any kind of question at all ebikemotorrepair.com
 

Kernow

E*POWAH Elite World Champion
Patreon
Founding Member
Jan 18, 2018
1,436
1,149
Cornwall uk
Hi Buddy. Not sure if you have solved this problem or not but it is very likely you simply have or had the spoke magnet on the rear wheel misaligned. It isn't impossible for it to have been dirty with something that interfered with the magnetic field as well. Not likely but not impossible. In the future the dealer should be able to clear the code instead of using your drill for an hour. clever idea though. That is definitely a way that works when the speed chips are detected. Anyway hope your problem is resolved and please let us know if you ever have any kind of question at all ebikemotorrepair.com
There’s no spoke magnet on this model , the magnet is fixed inside the rear lower stay and bolted to the disc bolts , so it cant really be moved easily . It was the first thing i checked in case there was a problem or something stuck to it , but found no problem
 

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