Mysterious Engine Light: Load Calculation Cross Check - Lower Limit Exceeded

Indi said:
If I recall correctly the manual was worded slightly vaguely, seeming to say that as long as it went through a range of values between 12 and 97 when the pedal went through its motion then it was within tolerance even if it didn’t cover the full 12-97 range, I’ll plug in VCDS and check it out again tomorrow
Click to expand...
The Ross-Tech notes mention G79 and G185, the two throttle pedal sensor, Block 03, & 04 Group 062. Both are shown as 0%, to 100%.
Mac.
 
PlasticMac said:
The Ross-Tech notes mention G79 and G185, the two throttle pedal sensor, Block 03, & 04 Group 062. Both are shown as 0%, to 100%.
Mac.
Click to expand...
12-97 is the range the manual gives as 'ok' for the diagnostic of that particular sensor, with anything outside indicating a problem:

The percentage value in display zone 4 should also rise steadily but without covering the full range of values
(12...97 %).
If the display values do not appear as described:
- Check whether connector of accelerator pedal position has become detached, is not properly engaged or
if the contacts of the connector are corroded.
- Test voltage supply and wiring to accelerator position senders
=>Page 97 .
 
I'd guess that applies to both throttle pedal sensors, G79 & G185, and, probably, that they should match/track each other?
Mac
 
Hi Mac, had a look through the Engine Groups and blocks as you suggested (this is all new to me so I'm learning something :) )
Noticed a couple of odd things -

1. Group 060, Block 2, Throttle Drive Angle Sensor reads 95.4%, Range is supposed to be 85 - 10% ?

2. Group 061, Block 2, Voltage Supply is Blank, Range is supposed to be 12.0 - 15.0 v ? I tried this with engine running and not and with logging on and off but block 2 remained blank in all cases.
 
NeilA2 said:
Hi Mac, had a look through the Engine Groups and blocks as you suggested (this is all new to me so I'm learning something :) )
Noticed a couple of odd things -

1. Group 060, Block 2, Throttle Drive Angle Sensor reads 95.4%, Range is supposed to be 85 - 10% ?

2. Group 061, Block 2, Voltage Supply is Blank, Range is supposed to be 12.0 - 15.0 v ? I tried this with engine running and not and with logging on and off but block 2 remained blank in all cases.
Click to expand...
No voltage sounds odd, but I don’t have anything to compare with.
Maybe another member could check as a comparison?
Suggest you do a Throttle Body Adaptation.
Not done it myself, but this from Ross-Tech:

Throttle Body Alignment (TBA) - Ross-Tech Wiki

wiki.ross-tech.com wiki.ross-tech.com
I think we're in the right area 🤞
Mac.
 
I think methodical checking, using measuring blocks, of all sensor related to EPC, is the only course of action. One of them is telling fibs. Check that the static reading makes sense, then, where possible, exercising them, to make sure they cover close to their full range. Very easy for me to say sitting in my metaphorical "armchair"
Mac.
 
1706194825241.png

1706194883841.png

This is blocks 60-62 with my foot off and on the accelerator pedal respectively.
As @NeilA2 found, zone 2 of group 61 is blank, even though when I hover the mouse over it it says "Specification: 12.0...15.0 V"
 
I suspect it may prove difficult to nail down as it is an intermittent fault, sometimes appearing with a mile and today not at all in a 12 mile trip. (It's the first time in a week or two that I've had a trip its not showed up in, of course it would be on one I was logging 🤣)
 
I also notice all 3 groups show "for EPC (G187)" when I hover over "Throttle Drive Angle Sensor 1", yet group 061 shows a different value entirely than the other two. Also the specification for group 060 is 10-85% whereas group 062 is 3-97%, making zone 1 group 060 out of spec?
I don't know enough about what I'm looking at to know whether this is normal or not but thought it was possibly worth mentioning
 
It is odd, that, what should be the same parameter, displays so differently.
Take a look at the descriptions for groups 060, 061, & 062 shown on this Ross-Tech document.
They are not quite the same.
The .lbl/cbl files are where they block descriptions come from.
When we were working on the FSI lbl files, we learnt that they were created, from original Audi info, in German, so typos, and interpretation errors are possible.
The lbl files are all frozen back in 2012. If anyone has access to the later cbl version, it would be good to see if anything has been updated.
Mac.
 
I did wonder if voltage supply not showing up could be anything to do with a battery being changed out and then not re introduced to the system. I think my battery has been replaced at some point in the past. I have no idea what the battery changing procedure should be. Any thoughts anyone?
 
Managed to get a log of some sensor values when the light comes on during my journey home, I sorted the data and graphed it in excel but cannot see anything that stands out to me. I've attached it here, the percentage based values use the axis on the right, whereas the rpm and manifold pressure are on the left axis.
Despite my attempts its still not the easiest to make sense of...

The light came on around the 180-185 seconds mark.

I think it just coincidentally lined up with me taking my foot off the pedal which doesn't make it easier to look for anomalies, I'll try and get another reading tomorrow.
 

Attachments

  • Log and Graph.zip
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NeilA2 said:
I did wonder if voltage supply not showing up could be anything to do with a battery being changed out and then not re introduced to the system. I think my battery has been replaced at some point in the past. I have no idea what the battery changing procedure should be. Any thoughts anyone?
Click to expand...
I'd not think so. More likely an error in the lbl file.
I'll ask Ross-Tech Support, they might know.
Having written it, I then forgot to post! I did ask Ross-Tech. Their reply was:
The label file [036-906-034-APE.lbl] has been created for various
vehicles and engine codes (see below). Consequently, it's possible that
not all configurations will display all the measuring values in every
field, which may result in some empty fields.

ref: Audi A2, Skoda Fabia, Caddy, Golf, Bora, Jetta, Lupo, Polo
Engine codes: APE, AQQ, AUA, AUB, BBY, BBZ, BKY
Mac.
Again, would be good to see if the later cbl version is the same.
Mac.
 
PlasticMac said:
I'd not think so. More likely an error in the lbl file.
I'll ask Ross-Tech Support, they might know.
Having written it, I then forgot to post! I did ask Ross-Tech. Their reply was:
The label file [036-906-034-APE.lbl] has been created for various
vehicles and engine codes (see below). Consequently, it's possible that
not all configurations will display all the measuring values in every
field, which may result in some empty fields.

ref: Audi A2, Skoda Fabia, Caddy, Golf, Bora, Jetta, Lupo, Polo
Engine codes: APE, AQQ, AUA, AUB, BBY, BBZ, BKY
Mac.
Again, would be good to see if the later cbl version is the same.
Mac.
Click to expand...
How do I get the cbl file? I have full and registered VCDS and as far as I know it’s up to date, are there separate add ins for certain engines?
 
Indi said:
How do I get the cbl file? I have full and registered VCDS and as far as I know it’s up to date, are there separate add ins for certain engines?
Click to expand...
As a registered Lite user, I'm not sure.
I know @Andrew is watching this thread, and he can give you more, as he's a full VCDS user too. I suspect he'll be along later.
Mac
 
Indi said:
How do I get the cbl file? ......
Click to expand...
Good Afternoon,

I suspect the cbl file does not exist, it is not worth Ross Tech creating one now for an old engine.

.CBL files are encrypted so no chance of reading them.

There is no 036-906-034-APE.cbl with my full VCDS but I have the 036-906-034-APE.lbl, you will be the same.

I expect when a particular cbl file is created and added to VCDS it replaces the corresponding lbl file if it exists since the lbl is now redundant. Hence the fact the lbl file is being used implies no cbl.

Label files are stored in the Ross-Tech directory normally on C drive. Navigate with File Manager to c>ross-tech>vcds>labels and you will see them all, too many to digest. Refine view further by using the Search in File Manager, top right, and entering such criteria as 8z. In this case enter 036 and you will see the label file.

lbl files are readable and editable with Notepad, just click on and it will pop up, but do not alter unless you know what you are doing.

Andy
 
PlasticMac said:
As a registered Lite user, I'm not sure.
I know @Andrew is watching this thread, and he can give you more, as he's a full VCDS user too. I suspect he'll be along later.
Mac
Click to expand...
As Indi has full VCDS I cannot contribute anything further even if I had an AUA engine to plug it into to.

Out of interest if you look at the screenshots of measuring blocks with our BAD engine in Media you will see a voltage is returned in Group 061.

Andy
 
I know that much of what on is not always useful, but this seems relavant:
The primary causes for an EPC light turning on relate to the throttle system. However, other conditions may also trigger the light. The most likely causes for an EPC light turning on in your Volkswagen are:
Brake light switch
Cruise control
Engine speed sensor
Mass air flow sensor
Throttle pedal
Throttle body
Traction control
So, we are, (probably),in the right area, but maybe a slightly wider net is required.
Mac.
 
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