evopilot

i hope that someday somebody on the internet reads this thread and can hopefully use3 my information to not spend so long trying to source the cause of the problem 😄

So an update. Last week after a few weeks of searching i was able to source some genuine VAG diagnostics cables to work with ODIS I picked up VAG 1598/42 and VAG 1598/39 This then allowed me today to check the signals being received by the ECU which narrowed it down to a fault on wire/pin 44 on the 94 pin side of the ecu, the ECU was seeing voltage permanently but this should have dropped to a earthed signal once the clutch was pressed in. The culprit wire came out of the master cylinder on pin 3 then split into two parts.... one length went into the convenience module in the boot and the second branched off and went into the ecu at pin 44 as i mentioned above. Pin pointing that the convenience module was getting the correct signal i was able to narrow down that the trouble was after the cable splits and went to the ecu. I ran a fresh length of cable myself from the split to the ecu pin 44 and BINGO she fired up, gave the car the once over on ODIS and the error was fully gone. Nearly six months of the car sitting up in my garage and shes back on the road

only thing that would make me not believe it was the mounts is that the problem suddenly goes away on the 5th start or so map does sound like a strong likely candidate imo

seen similar once and their was a wiring loom issue on the starter motor, best to get the faults if any read to help narrow it down just incase

Legend as always Steve, thank you

Anybody know roughly were too look for this?

thats a huge volume of diagrams im afraid id need something a little more specific

thats a shocking price

Invest in ODIS if you can, it goes far deeper then VCDS can

there are many, any particular ones you are looking for?

no need to code the battery to the car unless im very much mistaken also Kevin the best bit of VAG software you can buy is ODIS with a cable, there's a few usually on adverts.ie and are worth their wait in gold. If your using VCDS for coding its easy but for the deeper dive into your car and codes ODIS is the only way to go Ive tried them all over the years

yes it can be done with VCDS coding for sure, ive disabled the system myself. If you want to "hide" a fault i couldn't say with certainty but i would say it would be the same

the fault is in relation to lack of air flow detects at the EGR so if you have replaced the EGR itself id be taking off and cleaning the pipework as far upstream and downstream as possible from the EGR

The function is there in the car but as their is no SD card inserted it has never worked 😕

Cheers Steve, have you a link to the original thread and ill check it out?

very interested in following this thread, my car came without the SD card for maps and it bugs me i dont have navigation 😕

Small update but after installing ODIS and following the trouble shooting Ive narrowed down the issue, its a bit picture heavy but the below is the step by step of ODIS pointing out the ECU is not seeing the clutch pedal being pressed: Ready to be tested: Switch is being picked up as being pressed but the ecu/can cannot see the pedal being pressed J623 and G476 testing to follow asap but at least im no longer throwing darts at the issue

man i cant thank you enough for asking these guy the questions you have already, its much aprecaited. ive pulled up the flow chart for the convenience ecu, so tomorrow after work ill have a look were ive marked the red x and see what condition that wire is in and voltage etc maybe test for continuity, this is the wire i wasn't sure should have 6.8v on it after reading online to simply earth this connection to "trick" the ecu into thinking the pedal was pushed in

So connector from the loom replaced today with a fresh connector block and wiring, unfortunately its the same fault Audi advised today to use a genuine clutch master cylinder/switch on this make/model of car That leaves: Replace convenience ECU in boot as that is the component whats throwing the error (a long shot and not overly expensive) Replace engine bay loom section (most expensive of all options) Replace main ecu (bit of a hail mary this option and not sure on cost of ecu) Replace clutch master cylinder/switch with genuine one (this will be the 5th sensor/switch if i buy this... madness)

if you could get your hands on the voltage specs id be forever grateful mate Also side note ive ordered a new connector block a wiring from Audi, should be here Wednesday to try rule out the connector block itself

Alternative but expensive options which id rather not do due to the cost and no guarantee of helping would include, purchasing a new convenience control ecu, installing a new wiring loom or new main ecu My gut is telling me wiring loom issue and their seems to be allot of people breaking manual versions like mine so that might be an option but hopefully i can get a section of it and and the full car loom doesn't need to be purchased: Hopefully however somebody know the voltage specs on the sensor etc before i go down that road

OK so spent a good bit of time at this yesterday and even tried a new clutch position sensor (clutch master cylinder/switch 4) and im happy now the problem is not the sensor it can not be as the problem is following even the brand new sensors installed.... (side note if anybody is looking for a sensor i have a few spare for sale lol) Also to rule it out i even tried a hail Mary and purchased and fitted a brand new main battery, the thought behind this was sometime the engine would throw a fault for implausible starter signal which i read could be a symptom of a tired battery. so seen as the battery is 6/7yrs old now i installed a new one. So yesterdays testing: First off a continuity test between the connector that would connect directly onto the clutch sensor and the end point i could trace, the purpose of this testing was to try identify a severed/loose wire etc 1. Brown wire (Main earth for switch) checked and OK, also spliced the cable and created a new earth of my own to double check and that was OK too 2. Green/Grey wire (connection to Main ECU) checked and OK to 17pin coupler, checked and OK to exit wire leaving coupler and checked at pin 89 on main ECU all OK. 3. Blue/Grey wire (Park/Neutral to main harness) checked between plug and further up the cable unsure of actual end point of this wire. 4. Black/Blue wire (To fuse 2 & 4 fuse holder F) I could not tell where fuse holder F was or identify it correctly so continuity could not be verified. However their is voltage on the wire but more on that later. 5. Green/Yellow wire (Parking brake control unit connection) continuity unchecked as the error does not seen to be related and their is voltage on the wire but more on that later too. 6. Red/Blue (To fuse box drivers side doorway) continuity is OK entering and exiting the fuse Voltage at the connector: This test was done using a chassis ground/earth and by using pin 1 below for double checking 1. Brown wire (Main earth for switch) voltage not expected as earth wire and 0 volts found, satisfied earth is good due to above. 2. Green/Grey wire (connection to Main ECU) zero voltage found 3. Blue/Grey wire (Park/Neutral to main harness) 6.8v found 4. Black/Blue wire (To fuse 2 & 4 fuse holder F) 11.8v found 5. Green/Yellow wire (Parking brake control unit connection) 10.1v found 6. Red/Blue (To fuse box drivers side doorway) 11.8v found It would really help if i had some verification of what the voltages etc should be with the clutch pressed and depressed so if anybody could assist me on that i would be ever so grateful. Additional checks: Also i read online that connection wire 3 directly to earth on the loom side not coming form the sensor is a method to trick the ecu in thinking the pedal was depressed however i can confirm this does not work. Actually if wire 3 is snipped the clutch pedal operates correctly to a point and throws zero fault codes but the ecu has no way of knowing you have actually pressed the pedal in. If you earth it as mentioned above the fault trips immediately and we are back to square one. I am worried about this slightly as i see voltage on that wire now (earth test was done prior to voltage test BTW) so by the main harness sending 6.8v down this wire to the connector and i earth it that would naturally cause a fault or trip a fuse i would have thought but no fuses were tripped. Also i gained access to the convenience control ecu down the back and checked that for loose wires but all seemed ok Apologies for the long winded reply but i hope Ive broken it down into readable chunks and either somebody can help me or one day somebody on the web finds this in a search and it helps them hopefully by then my issue is resolved. Closing questions: Does anybody know the voltages i should be seeing or the voltages the car should be expecting etc? Should their be voltage on wire 2? Should their be voltage on wire 3? Where is fuse holder F according to audi?

you need to gt your hands on Elsawin buddy that will have everything you need if your stuck drop a message here with what diagrams your after and ill screenshot it for you

Ive thought about trying similar but the master cylinder has 6 connectors unlikey the older ones that have two 😞

The only coil that is present is a large spring that gives the pedal itself the tension i cant see other switch's in the vicinity other then the brake pedal switch which is different 😞