Best thing to use? MAF cleaner?

I think my peculiar 01314 code in the abs is still banging on about the original code I got when the power cut. One possible cause being IAT sensor so may try giving it a clean. Last run car was ok but abs and tcl lights doing strange things with ignition on, engine off. It could be sorted as last ignition cycle all fine. I just have a nagging feeling something may come back to haunt me. Fitting a new brake pedal switch today seemed to work well but like I say I'm still not 100% sure. Annoying thing is when this 01314 code for check dc memory pops up, I have no other codes to check! How annoying is that?

I use IPA to clean mine, or injector cleaner at a push.

 

There are some tests that you can carry out on the ABS unit in VCDS if you think you may have issues, but experience of other vehicles with ABS faults has always got me to check that battery voltage is consistent too.

 

If the voltage dips, you may be getting to a threshold where it throws error codes. This is a simple check that costs almost nothing to do, just get a suitable length of twin core, carefully route it out of the bonnet and in through the n/s window. Connect the cable to the battery with suitable terminals, and connect to a multimeter in the car. Get a passenger to monitor the voltage while you drive. You may also be able to log battery voltage in VCDS, but I've never looked.

 

Not sure it's actually an abs issue as such, just that code and light trying to urge me to sort something else out. Tell you what though Phil I ain't got a clue when it comes to electrics. I do have a multimeter though. Would just checking the battery terminals at idle tell me anything? If so how do I set up the multimeter for that? Do you think that fuse box thing on top of the battery and the earth could have something to do with it?

Is maf cleaner ipa by the way sorry?

 

Is maf cleaner ipa by the way sorry?

Not sure, do you have a link to the product at all?.

 

As regards battery, yes, do a voltage reading at idle after starting it, then see if it rises as you pick the revs up to about 1500rpm - do that bit with a load on the system like headlamps on and heated rear window. Post back the readings you get.

Cheers Phil what do I set the meter to? I don't have a link I'm afraid and the can doesn't really state it, but I've just done a search and people appear to have used maf cleaner, contact cleaner and even Carb cleaner. Just got to be careful not to damage the wire sensor.

sounds like a plan, as regards meter, set to DC volts in a range to read up to about 20volts, that should be adequate, do not select a range lower.

Thanks Phil, will see what I can do with 1 pair of hands and 1 pair of feet.

Ok so checked battery:

Cold with engine off (overnight) 12.61 first reading, then 12.41 strangely.

Cold start idle 14.3

Idle loaded (fan, stereo, lights, rear window) 14.18

Then I set throttle with a brick to 1500rpm, loaded 14.2

Fine then yes?

Cleaned intake air temp sensor (will post a little how to later) and have to say you could visibly see a film of dried black oil over the wires. As soon as I sprayed with Carb cleaner the copper colour began to get revealed so it now looks better, not run car yer though. I may need a new sensor as the top of one of the wires looked dark and this wasn't oil I don't think. Anyway, what is there is now clean.

I decided to disconnect the battery and then clear any codes with vcds to reset everything, so time will tell I guess. I suspect I may have a small air leak somewhere but whatever it is it is small.

I was thinking about putting my standard airbox and scoop back on instead of the modded box with 80mm pipe. Would you recommend I do that?

Oh I did notice my injectors and head area seemed more ticky/clicky than usual, that could just be in my head though plus car wasn't run up to temp.

Ok so just went to clear all codes from disconnecting battery. While running vcds with ignition on, tcl came back on and abs started flashing. Bear in mind car hadn't even been started. Started it abs continued to flash and tcl came on, they then both went off and stayed off. Taking it for short run now will see if they stay off.

Short drive, seemed to run smooth. Pulled up at destination abs flashed. Turned engine off, went through another ignition cycle lights stayed off, sat at idle for ten mins, no lights, engine off, another ignition cycle drove home, no lights.

Will just add that even after abs flashing there is no code, not even the red herring 01314 code. Do you think I'm looking at a good old fashioned wiring issue? Must admit I've not checked the relays yet, fuses look fine and carrier on top of battery also fine. There is a split in my scuttle panel around halfway along, is there still some panel underneath to protect ecu? I'm hoping it's not a bit of water ingress...

Voltage figures look ok, I would be inclined to check the connector onto the abs unit and look for any manky pins in the connector, something does not want to play nice in your playroom there.

Cheers Phil, which connector is that and where is it? I've not explored abs system before. I checked brake fluid level and got some contact cleaner on the plug for that in case it was anything daft. Not driven it since mind.

I'm also thinking abs sensor/s but aren't codes thrown pretty efficiently for that?

I've also put my standard bottom of airbox back on. I don't think it's totally connected but I just want to take a bit of pressure off the maf. With the cold feed it was pulling in 170g/s which is a fair whack and good for 212 break. But on vcds extrapolating the torque figure shows around 207bhp which I think is about right so I just want to reign in the intake to balance it out a bit.

Sensors usually throw codes even when they are starting to fail, my Father in Law had one on and off for 3 months til it finally went. I'll try to get a piccie for you of the connector on the ABS pump and post back later. Just be careful taking it off as they can be a little stubborn, a squirt of WD40 works wonders to start it moving.

This is about the best I could find on the piccie front:- http://workshop-manuals.com/skoda/octavia-mk1/brake_systems/abs_adr_tcs_edl_esp/electric/electronic_components_and_fitting_locations_abs/edl/tcs_mark_60/removing_and_installing_the_hydraulic_control_unit_and_the_bracket/

it is item 7 that you need to check.

 

Although to be honest I was thinking while I was looking, what is the state of the fuse box on top of the battery, is it starting to melt underneath?. Also check the state of the ABS fuse, as these can hairline crack, but look ok at first glance, it is only when you undo the securing nut that it falls in 2 halves. I would also check the main battery earths under the tray, as they can cause problems too. I would check these before you go to the ABS control unit.

 

I did have a bit of a visual check around of the box on the battery and the earth and it all looked ok. Will have a closer exam. Where is the abs fuse? Cheers Phil

Thanks for the pic, take it the plug is just below the reservoir next to the strut?

Found the fuses for abs

http://forums.vwvortex.com/showthread.php?951306-Here-s-a-list-of-fuses-for-MKIV-cars-%28fuse-too-for-search%29

Checked battery fuse carrier underneath, no melting all looks clean as a whistle. Pulled out abs fuses look clean although I will replace them just in case there is a crack I can't see like you say. The in car fuse related to abs/esp (presume it's just for the dash signal/light?) whilst is intact does look like at some point it has got rather warm, there is slight charring on it so will also replace this.

Been looking through some stuff on abs unit once again it seems codes are thrown readily for it, seen where it is and don't have time to check it just yet, how the hell do you actually get access to it? It's in a very awkward place. Think I'll definitely try these fuses first.

Earth below battery also looks fine, what am I looking for with that, what kind of signs that it's playing up?

If the fuse is in one piece, it wont be a problem, when they go, they crack but look like they are in one piece. As soon as you loosen the mounts, they fall in 2 bits.

 

The ABS connector is a pain, you just have to struggle I'm afraid, hence the WD40 comment earlier.

 

As regards the earth point, take the mounting nut or bolt off (there is more than one earth point), and inspect the earth terminals to make sure they are bright and clean - also check the body points that the cables secure to and make sure they are clean too. Before you loosen the earth points, take the battery terminals off first, to avoid any minor disasters if you slip with a spanner or something.

 

A sign of an earth playing up, really is the sort of behaviour you are experiencing - oddball intermittent faults with no obvious cause.

 

Ok, cheers Phil, where are they all? Are they visible/accessible?

The abs unit/connector is the one below the airbox near strut?

The ABS unit is basically one unit containing an electric pump, a hydraulic valve body and an electronic control unit. When you look at the unit you will see that the connection is like a mini version of the engine ECU plug, and is the only one in view (item 7 in the picture). From memory, I seem to recall you pull a lug upwards on the plug - like the window control unit plug idea. If you follow the brake hard lines from the master, you will see where it is. I would suggest you don't do anything to get air in the system at the ABS unit hydraulics, as you will only be able to expel it by using VCDS in correct mode to run the pump.

 

On my VRS, which is an 03, I had an earth point under the main battery tray, which you could only get to with the battery out, when I looked at my friends 02 when we were stripping it, his was on the leg itself, so there would appear to be 2 options.

Cool, I'll lift out the battery and take a look, mine is late 03.

Right, progress (in a way). Thought I'd try a short run see if anything had settled down, tcl and abs light came on and stayed on. Didn't go anywhere. Lifted out battery found 3 earths there, cleaned up and put all back. Tcl light didn't stay on but abs did, oh and the handbrake light is flashing and beeping. Vcds says

18057 powertrain data bus

Missing signal from abs controller p1649

Also had 18010 voltage too low, I assume from battery being disconnected. As I cleared the codes, 18057 came straight back.

Scanning abs block for codes = no response from controller.

Suppose I need to check unit plug if I can figure out a way to get to it...

Also getting 01316 abs no communications