HarleyTechTalk

Technical Forums => General => Topic started by: jack_top on April 23, 2021, 02:02:34 PM

Title: C0562 abs low voltage problem
Post by: jack_top on April 23, 2021, 02:02:34 PM
I'm having a problem with a code C0562 that showed up uninvited on my Electra flhtcu 2008 display. Abs light is on after starting the engine.

I've read almost all the other posts regarding this code, checked the accu (voltage OK, 1yo, just charged), ground on a battery (ok, cleaned the connections), fuses (ok +cleaning the contacts), front and rear sensor and cables (no cable breaks, no short circuits, no fault codes regarding front or back sensor), checked charging voltage (13.5V on idle, 13.9V - 3000rpm). I thought that there might me a long drop in a voltage when starting the engine, so I connected with extra cables accu from vw multivan (while running) - battery voltage during engine start dropped to 11.9V but abs light and code appeared. Final step was cleaning the plug of the abs ecu, checking voltages on pin 10 and 20 (the same as on accu), on pin 19 (B+ with ignition, 0V with ignition off).
Ground on pins 1 and 11 is 0.4ohm with ignition off and 80ohm with engine working. That's the only thing I don't know if is correct... Shouldn't it be 0.4 ohm all the time?
If you have any other ideas, besides changing abs ecu, please share. Thanks. Jacek

Title: Re: C0562 abs low voltage problem
Post by: kd on April 23, 2021, 02:25:40 PM
Welcome to the HTT site.  There is tons of valuable information here.  Much is in reserve and you can find it by using the Search feature. You should probably read this (https://harleytechtalk.com/htt/index.php/topic,96447.msg1121852.html#msg1121852) from another member's post a while back.
Title: Re: C0562 abs low voltage problem
Post by: Coyote on April 23, 2021, 02:41:22 PM
You can't use the ohm setting on a meter with the circuit active. If you want to check the ground under power, put your neg meter lead on the negative battery terminal, then put the positive meter lead on pin 10, 20. Set the volt meter to milivolts and see what is reads.
Title: Re: C0562 abs low voltage problem
Post by: fleetmechanic on April 23, 2021, 05:28:44 PM
Don't know if it's related , but we had a couple of '08 and '09 FLHTPs with ABS that showed low voltage or No RSP codes and it was stretched or pinched wires on one or both leads going to the front wheel sensor along the frame neck. Ususlly right near the large P clamp.
Title: Re: C0562 abs low voltage problem
Post by: jack_top on April 23, 2021, 10:53:44 PM
Quote from: kd on April 23, 2021, 02:25:40 PM
Welcome to the HTT site.  There is tons of valuable information here.  Much is in reserve and you can find it by using the Search feature. You should probably read this (https://harleytechtalk.com/htt/index.php/topic,96447.msg1121852.html#msg1121852) from another member's post a while back.

Already did everything from this and other posts I've found :-(
Title: Re: C0562 abs low voltage problem
Post by: jack_top on April 23, 2021, 10:56:56 PM
Quote from: fleetmechanic on April 23, 2021, 05:28:44 PM
Don't know if it's related , but we had a couple of '08 and '09 FLHTPs with ABS that showed low voltage or No RSP codes and it was stretched or pinched wires on one or both leads going to the front wheel sensor along the frame neck. Ususlly right near the large P clamp.

True. I think it is the most common problem with abs on those bikes. I've already checked the wiring going to the front and back sensor. Also, there are no additional fault codes shown on a motorcycle computer.
Title: Re: C0562 abs low voltage problem
Post by: jack_top on April 24, 2021, 04:59:20 AM
New codes appeared all of the sudden C1043 Pump Motor Stalled and C1017 Pump motor power circuit open fault.. Can anyone help where does this circuit start and end and what can I do? Thanks.
Title: Re: C0562 abs low voltage problem
Post by: kd on April 24, 2021, 06:04:09 AM
If you don't have a factory service manual, it's a great investment.  The wiring diagrams are at the back.  You may find it in the Instruction Sheets Section at the bottom of the home page. This (https://harleytechtalk.com/htt/index.php/topic,16691.0.html) is a shortcut to them.
Title: Re: C0562 abs low voltage problem
Post by: jack_top on April 24, 2021, 12:48:35 PM
Quote from: kd on April 24, 2021, 06:04:09 AM
If you don't have a factory service manual, it's a great investment.  The wiring diagrams are at the back.  You may find it in the Instruction Sheets Section at the bottom of the home page. This (https://harleytechtalk.com/htt/index.php/topic,16691.0.html) is a shortcut to them.

Thanks, but I'm getting 'The topic or board you are looking for appears to be either missing or off limits to you.'
Title: Re: C0562 abs low voltage problem
Post by: kd on April 24, 2021, 02:18:50 PM
It must only b e available to supporting members.  Some of us donate to the upkeep of the site.  There's lots of extra benefits when you do.  I guess access to these libraries are one of them.  I for one have always felt it was good value. In the mean time a genuine Harley Factory Service manual is where the diagrams are.  If you don't have one you will benefit greatly by getting one.  By Genuine I mean not a Clymer or other aftermarket version.  They lack important detail.  Orrrr .... consider becoming a site supporter too.  :wink:

I just found this site information at the start of the donation page.  It explains what you get for your extra support.

https://harleytechtalk.com/htt/index.php/topic,20023.0.html
Title: Re: C0562 abs low voltage problem
Post by: jack_top on April 26, 2021, 01:00:54 AM
I'm waiting for a Clymer manual to arrive tomorrow. These are annoying problems...
Title: Re: C0562 abs low voltage problem
Post by: jack_top on April 30, 2021, 01:40:34 AM
In Clymer flow charts (Fig 167) I read "Operate the system within 6,5V and at a speed above 5mph". What exactly mean "Operate the system within 6,5V"? Thanks.
Title: Re: C0562 abs low voltage problem
Post by: kd on April 30, 2021, 06:34:46 AM
It sounds to me to be missing part of the explanation. Did you read all of the material leading up to the test procedure?  Clymer is notorious for incomplete info. I won't use one and would suggest you see if you can find a Factory Service Manual.  You will get a much better description.  Maybe someone with more experience on the ABS system trouble shooting can fill in the blanks.
Title: Re: C0562 abs low voltage problem
Post by: jack_top on May 14, 2021, 04:54:46 AM
Update. I've changed ABS module, paired in HD service, and now I'm having C1025 and C1032 errors present. What is going on?
Title: Re: C0562 abs low voltage problem
Post by: Fugawee on May 14, 2021, 06:13:26 AM
I don't know if this helps You or not...or if You are already aware of what those codes are.

C1025=Front Wheel Speed Sensor Intermittent Signal
C1032=Front Wheel Speed Sensor Open or Shorted
Title: Re: C0562 abs low voltage problem
Post by: fleetmechanic on May 14, 2021, 09:11:13 AM
If the wires to the front sensor are ok it could be the encoder in the wheel bearing itself.  We cured  one like this by replacing the bearing.
Title: Re: C0562 abs low voltage problem
Post by: jack_top on May 14, 2021, 11:54:17 PM
Quote from: fleetmechanic on May 14, 2021, 09:11:13 AM
If the wires to the front sensor are ok it could be the encoder in the wheel bearing itself.  We cured  one like this by replacing the bearing.

So it's possible that the abs front tire sensor is OK and it's a wheel bearing problem?
Title: Re: C0562 abs low voltage problem
Post by: rigidthumper on May 15, 2021, 04:59:35 AM
I found a spot on some early ABS touring bikes, especially cop bikes, where the wire would break inside the sheath- follow the wire from the front sensor to where it plugs into the factory harness-unplug it, and set aside. The break would usually occur between the plug and where the harness goes under the fuel tank. The wire would break inside the insulation, due to repeated flexing. You have to gently pull on the plug, effectively stretching the wires- if the wire is broken inside the sheathing, you'll see the plastic insulation get thin in the broken area. May be one, or both wires. May have to cut the conduit to allow access for repair. Repair is done with solder, heatshrink, and maybe a new piece of wire to ensure the stress is removed from the wire. Plug in, clear codes, and verify repairs completed successfully.
Title: Re: C0562 abs low voltage problem
Post by: jack_top on May 16, 2021, 04:11:55 AM
Quote from: rigidthumper on May 15, 2021, 04:59:35 AM
I found a spot on some early ABS touring bikes, especially cop bikes, where the wire would break inside the sheath- follow the wire from the front sensor to where it plugs into the factory harness-unplug it, and set aside. The break would usually occur between the plug and where the harness goes under the fuel tank. The wire would break inside the insulation, due to repeated flexing. You have to gently pull on the plug, effectively stretching the wires- if the wire is broken inside the sheathing, you'll see the plastic insulation get thin in the broken area. May be one, or both wires. May have to cut the conduit to allow access for repair. Repair is done with solder, heatshrink, and maybe a new piece of wire to ensure the stress is removed from the wire. Plug in, clear codes, and verify repairs completed successfully.

This could be the case. I'm following clymer guide regarding the error codes and I'm having sudden drop of the voltage measuring on pin 18 while wiggling the handlebar. It seems that the blac/violet cable has a faulty wire.
Title: Re: C0562 abs low voltage problem
Post by: jty on May 19, 2021, 12:35:42 AM
In my 2008 FLHRC I've had that for both front and rear. The culprit were the abs line connectors under the right side cover and headlamp. Once you open and close the connectors few times, the tension of the contacts wear out. I twisted the female contacts with a needle and the problem was solved
Title: Re: C0562 abs low voltage problem
Post by: jack_top on May 19, 2021, 12:07:55 PM
Mine problem was solved with a new black violet and black blue wires replacement. Because of the front plug and it's poor connection I just went for a solid connection knowing that in case of... I would have to cut the cable again. Codes dissappeared, I went for a drive and everything seems to be in order. Abs is working. That was mistery solving adventure. Thanks for helping :-) and CU on the roads in Poland :-)