Brake issues after lay up Euro T1N

Good evening from The isle of Portland in dorset, Uk sprinter People!. I have an issue with my 2003 sprinter brakes, I am hoping that someone will be kind enough to give me some advice.

So i bought this van from a friend, it has been layed up for a while due to having a front to rear brake pipe rusted out.
Anyhow got that job sorted with new flexi's, front discs and pads, slider pins cleaned and regreased.
Was hoping that it would bleed up but i have had endless issues with it. brake pedal is spongy, quite hard with ignition off but falls to the floor when engine running.
brake pad light abs and asr light remain on immediately once running. Ihave been told of an issue where there is low voltage the the module, but i am getting 12.08 v Is there anyone out here who has any ideas for me?

Re: Brake issues after lay up

Islebiker said:

...
brake pedal is spongy, quite hard with ignition off but falls to the floor when engine running.
...

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What you describe may be normal. Review this post.
https://sprinter-source.com/forum/showthread.php?p=112320#post112320

Islebiker said:

... brake pad light abs and asr light remain on immediately once running. I have been told of an issue where there is low voltage the the module, but i am getting 12.08 v Is there anyone out here who has any ideas for me?

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You should scan for DTC's using a Sprinter specific scan tool. That should give you a direction.

vic

Re: Brake issues after lay up

12.08V with the engine running is far too low. The voltage should be around 14V.

Re: Brake issues after lay up

You may not have 12.8 V to the module, but through the module. It might be worth finding and cleaning the ground lug for the ATC module (I believe under the drivers seat). A corroded ground can easily restrict electrical flow enough to cause a drop of 2V

The brake pad light is the wear indicator grounding out. If you replaced the pads and not the wear sensors that light will stay on until the sensors are either replaced or disconnected.

So far as the brake feel, you might try using a vacuum bleeder at each corner until you have no bubbles and clean fluid coming out.

Re: Brake issues after lay up

Wow thank you all of you for all the quick replies and info. I shall test voltage with engine running! doh! Thank you Brennwagon for giving me the location of the earth, i had heard of issues but did not know where to look. have a mityvac bleeder here which i use on bikes and have gone round several times. oh and i have found some broken inulation on a pad sensor wire, so 1 down 2 to go! Aqua Puttana thank you for your suggestions, gonna try the brakes out again later. Sadly, used a snap on reader and it would not talk to the van. have a cheap one here that doesnt have all the options on it so gonna try that. Once again thank you for the replies.

Re: Brake issues after lay up

Thank you for your replies, I have gotten a little further along the path of finding the issue and have managed to isolate where the issue may be. I would very much appreciate any tech advice possible at this stage.
So when ignition is turned on abs and asr light on. after about 5 secs the abs light goes off for a fraction of a second and then re-lights. Due to this i suspect it is not a speed sensor as the light comes on without moving. i can hear the relay click on and off with the abs light. when ignition is turned on i will get a click from the abs pump but no more.
Ok so have done a few smaller jobs to rule them out
cleaned and inspected all fuses.
done lock to lock reset after each job.
replaced brake light switch.
checked and cleaned earth under seat.
checked voltage at the abs pump pins with engine running and got 14v on 2 of the pins
put power direct to abs motor, and the motor spins.
unfortunately the van wont talk to scan tool still so a bit stuck!

Re: Brake issues after lay up

Islebiker said:

...
unfortunately the van wont talk to scan tool still so a bit stuck!

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Being that your scan tool won't communicate.
Depending upon type and wiring, some aftermarket units have been known to interfere with OBDII communication. There are 2 ea. CAN Bus systems. One for the engine, the other for peripherals so not all CAN bus problems will affect engine running.

Have you tried a different scan tool? A generic will do to test basic communication.

Are you using a Euro round connector to parallel OBDII adapter/cable? Some are known to not have a full complement of pins/connections.

My first priority would be to establish scan tool communication. Once that is up to speed some of your other problems may go away.

vic

Re: Brake issues after lay up

yes have basic scan tool i am testing on it tomorrow instead of the snap on one. still be using the same plug though as that is the only one i have available. converts to standard 16 pin.came with the snap on scan tool i believe.

Re: Brake issues after lay up

Islebiker said:

yes have basic scan tool i am testing on it tomorrow instead of the snap on one. still be using the same plug though as that is the only one i have available. converts to standard 16 pin.came with the snap on scan tool i believe.

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Hi from a fellow Brit!

I have a basic 14 pin to 16 pin cable (from eBay) and with this cable I can only access the Engine ECU as only four pins are actually populated, this may be the source of your no communication problem.

Compare the 'pin out' of your cable to my write up here... https://sprinter-source.com/forum/showthread.php?t=77817

I also have a genuine Autel adaptor and a fully populated AliExpress cable (although I had to reconfigure the latter to match the Autel) and with either of these I can access all modules on my T1N.

I hadn't fully read your OP with your location and associated that with your no comms issue at first.

Keith.

Re: Brake issues after lay up

This thread is now in the wrong forum section, please can it be moved to a correct location.

Thanks.
Keith.

Thanks Keith. I have just got another cable and that one has just tested as 4 wires! gonna test the old one now! not sure how to move this post though. bit above my level of ability there!

Islebiker said:

Thanks Keith. I have just got another cable and that one has just tested as 4 wires! gonna test the old one now! not sure how to move this post though. bit above my level of ability there!

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Unfortunately you will only ever be able to access the Engine ECU (ECM) with a '4 wire' cable.

The only cable with all pins connected I have found is the one from China via AliExpress. With a discount code for first purchase it cost me less than £3 and arrived in under a week.

BUT - it still did not work for anything other than the ECM until I resoldered the pins on the OBD end as per my table on the earlier thread.

The only other way I have found to access any other module is with the Genuine Autel 14 to 16 pin adaptor (which has the pin-outs I copied for the 14 wire cable).

Keith.

THank you for your response. I am sorry that I do not know how to move this thread.
I have got a bit further on now, i have had a friend over and we have started checking wheel sensors as we have had no luck getting the the obd2 port to work. we have snipped the rear sensor wires and tested them, we got around 1.6k ohms on both rear sensors still and an ac pulse of .2v when tyres revolved. (we did adjust gap one side to get it working so at least we have solved an issue i didnt know i had yet!) But we did find that there was a very low voltage out to the sensors less that a volt. Could this be why my abs and asr light are not going out? and possibly the port issue too?

Thank you for the advice. i have tested the new lead and it is 4 wire, the other lead that i was using i have tested continuity and it has all pins.

I Have had a friend help me over the weekend and we snipped the wires to the rear sensors to get a test on them. about 1.6 k ohms each side and .2 vac when wheels spun. (Had to adjust gap one side so sorting an issue i didnt know i had yet!!!) We tested for voltage going to sensors and found it very low less that a volt. Could this be the reason the abs and asr lights stay on? and possible why the obd2 port doesnt work?. Oh and edc light stays on too not sure if this could be related.

Anyone got any ideas?

Islebiker said:

Thank you for the advice. i have tested the new lead and it is 4 wire, the other lead that i was using i have tested continuity and it has all pins.

Anyone got any ideas?

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Do the pin-out connections of your second lead match this table...



Keith.

Thank you for the Diagram keith. I have been using the lead from my friends set which is a launch system. are you saying that the pins in this are not the same as the sprinter one?. and so the mod to communicate with it?.

Islebiker said:

Thank you for the Diagram Keith. I have been using the lead from my friends set which is a launch system. are you saying that the pins in this are not the same as the sprinter one?. and so the mod to communicate with it?.

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Quite possibly!

My MD802 and AliExpress 14 wire lead would only communicate with my ECM until I resoldered the pins to match my Autel CV-14 adaptor (which does communicate with all modules).

Keith.

Thank you so much!! I have ordered the lead from aliexpress. got my fingers crossed! hope you have a great xmas and all the best for the new year!

Hi guys thank you for your help. I have a friend of mine coming down over the holidays to have a look for me. He has the kit to run the brakes through the bleed prodedure and remove faults. hopefully he can find out the issue! I havent asked him to before because he lives around 200 miles away!. Sterling effort on his behalf and i can see myself being indebted for a few drinks to come! In the meantime he has sent me some tech data that you guys may find handy. I have been testing the circuits and have eliminated most of the components so is starting to look like the module. got a chart showing individual pin locations in the obd2 plug too. will upload as soon as i find out how. have them downloaded on my computer at present.

Hi @Islebiker did you ever make any progress with this? It seems I'm having a very similar issue and just wondering if you managed to get to the bottom of it?