What do my DTC Codes mean (VAG-COM)?

956 Views 19 Replies 8 Participants Last post by CoolWhiteVR6, Feb 20, 2002

BoraVR6

Discussion Starter · Feb 13, 2002

3

I had a CEL come on last week about 5 miles after reinstalling my airbox. I rechecked my connections to the airbox and the MAF sensor, and ordered the VAG-COM software/connector. That came today and I pulled the following codes:
17978 Electronic Control Module blocked by immobilizer 35--10 intermitent
16804 Catalyst System, Bank 1 Efficiency Below Threshold
17536 Long Term Fuel Trim multi., Bank 1 System too Lean
18020 Power System (B+) Terminal 30 Low Voltage
#1 (17978) I think is related to an intermitent problem where about once a month, I turn the ignition on, the immobilizer kills the engine, and the little key icon flashes on under my Tach (then repeat about 6-8 times and the engine finally turns over) . Not sure why this is happening.

#2 (16804) and #3 (17536):seem to be the same thing, but I don't know if this is related to me initially having a loose connection to my airbox/MAF connector or something else all together.

#4 (18020) Not sure if this is related to the others or not
Anyone seen these DTC codes before / have an idea what they mean?
TIA http://****************.com/smile/emthup.gif

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regthagimp

· #2 · Feb 13, 2002

Re: What do my DTC Codes mean (VAG-COM)? (BoraVR6)

#1 - i got number DTC when i used a transmitter that wasn't matched to my immobilizer. I cleared it and i matched the key and it went away. try matching your keys again.
#2 and #3 i have no clue, try signing up to the vag-com group on yahoo. they are very helpful.

BoraVR6

Discussion Starter · #3 · Feb 13, 2002

Re: What do my DTC Codes mean (salty peaks)

quote:[HR][/HR]#1 - i got number DTC when i used a transmitter that wasn't matched to my immobilizer. I cleared it and i matched the key and it went away. try matching your keys again.
#2 and #3 i have no clue, try signing up to the vag-com group on yahoo. they are very helpful.[HR][/HR]

Thanks for the tip. I'm joining the VAG COM yahoo group now. http://****************.com/smile/emthup.gif

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adg44

· #4 · Feb 13, 2002

Re: What do my DTC Codes mean (VAG-COM)? (BoraVR6)

#3 makes me think either your MAF is bad or an O2 sensor is bad. http://****************.com/smile/emthup.gif
Let us know what you find out.

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JettaRed

· #5 · Feb 13, 2002

Re: What do my DTC Codes mean (VAG-COM)? (BoraVR6)

You said you reinstalled your airbox. what was there before? did you have your maf disconnected. also, did you disconnect your battery for any reason. I've never had those codes, but that's all I can think of.
You may just want to clear them and see if they come back. Power System (B+) is your battery. Codes could be old and not related. They stay until they are cleared.

BoraVR6

Discussion Starter · #6 · Feb 13, 2002

Re: What do my DTC Codes mean (JettaRed)

adg44 and JettaRed: thanks for your thoughts http://****************.com/smile/emthup.gif
On #2 and #3: Yes, when I had my airbox out I disconnected the MAF Connector. I'm not positive that it was plugged back in all the way. I checked it again after the CEL came on, but it didn't appear to have much play in it.
#4: I've had my battery disconnected a few times since in the last 15k (I'm at 55k now, the last time codes were checked by a dealer was at 40k an none were reported). It was disconnected when I installed a set of Hella driving lights and disconnected again when I changed the slots my single DIN VW CD player and the radio sat in. So the Battery one may be related to one of those.
I cleared the codes, and plan on checking to see if they come back.
Aside from reoccurance of codes #2 and #3, would I be able to tell from engine behavior if my MAF/O2 was bad? Because I haven't noticed any changes in the way the engine behaves.

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BoraVR6

Discussion Starter · #7 · Feb 13, 2002

Re: What do my DTC Codes mean (BoraVR6)

Bump http://****************.com/smile/emthup.gif

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JettaRed

· #8 · Feb 13, 2002

Re: What do my DTC Codes mean (BoraVR6)

If the MAF or O2 sensors are bad, you may notice worse gas mileage. Some people report bad engine performance. Keep in mind the MAF and O2 sensors are used to control fueling by the ecu according to programmed fuel maps. If either one starts reporting bogus data to the ecu, your fueling will get messed up and cause performance problems.
One way to tell if you might have problems is to look at engine display group 032 for long term trim (2nd block). If the reading is outside of +/- 10% and you have NO engine mods (like a chip), then you probably have a problem. If it's within that range, you're probably OK.
EDIT: If you're going to play around with the VAG-COM much, you should really get the Bentley on CD. It contains a lot of diagnostic procedures that I don't think are in the paper copy.

[Modified by JettaRed, 9:32 AM 2-13-2002]

brian1377

· #9 · Feb 13, 2002

Re: What do my DTC Codes mean (JettaRed)

Also, if you have 55K on the car, you may want to change the O2 sensors. I normally change them every 50k to 60k just to get the best fuel mileage from the car. Just a thought.

CoolWhiteVR6

· #10 · Feb 14, 2002

Re: What do my DTC Codes mean (VAG-COM)? (BoraVR6)

Just to rehash. These are the codes I pulled on Tuesday when my CEL first came on:

quote:[HR][/HR]17978 Electronic Control Module blocked by immobilizer 35--10 intermitent
16804 Catalyst System, Bank 1 Efficiency Below Threshold
17536 Long Term Fuel Trim multi., Bank 1 System too Lean
18020 Power System (B+) Terminal 30 Low Voltage [HR][/HR]

I'm at 55,000 miles and before Monday the last time the codes were checked was at 40,000 (none were found). I cleared the codes above and my CEL went out.
This morning my CEL came on again and this is the code I have currently (a repeat offender from above):
17536
VAG-COM description: Fuel Trim: Bank 1 (multi) System too lean 35--10 intermitent
Bentley description: Long Term Fuel Trim multi., Bank 1 System too Lean
So now that this is the ONLY code I have, I'm starting to think O2 sensor, but I'll find out Monday when I take into the dealer.

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GmanX

· #11 · Feb 15, 2002

Re: What do my DTC Codes mean (CoolWhiteVR6)

OOOOOOh you got a bad MAF!!! Be proud

Jettaway

· #12 · Feb 15, 2002

Re: What do my DTC Codes mean (GmanX)

Does the VAG-COM software come with instructions on how to change different settings on you car or is it self explanatory?

JettaRed

· #13 · Feb 15, 2002

Re: What do my DTC Codes mean (Jettaway)

quote:[HR][/HR]Does the VAG-COM software come with instructions on how to change different settings on you car or is it self explanatory?[HR][/HR]

Not really. YOu need to go to the vag-com site and post a question there. some other people who have figured things out, like how to make the doors unlock when you remove the key, will point you to sites where that stuff is covered.
I'd really like to get the "booklet" (if there is one) that describes all the code changes you can make.

GmanX

· #14 · Feb 15, 2002

Re: What do my DTC Codes mean (JettaRed)

Get a service manual. Without it a VAg-com isn't of much use. You need it to decode the data.

JettaRed

· #15 · Feb 15, 2002

Re: What do my DTC Codes mean (GmanX)

quote:[HR][/HR]Get a service manual. Without it a VAg-com isn't of much use. You need it to decode the data.[HR][/HR]

I think the question was how to recode things, not how to interpret the codes. You're right though, the vag-com is limited without the Bentley CD.

CoolWhiteVR6

· #16 · Feb 15, 2002

Re: What do my DTC Codes mean (JettaRed)

My current question is for a bone stock VR6 engine (no K&N/no exhaust/no chip) with the following code:
17536 Long Term Fuel Trim multi., Bank 1 System too Lean
Has anyone had this code and what was the cause/result/fix? BTW, I'm using 91 octane gas, but both of these codes have been thrown on the same tank of gas.

GmanX

· #17 · Feb 15, 2002

Re: What do my DTC Codes mean (CoolWhiteVR6)

yep I had that code. Bad MAf was the cause. Call VW get the to pay for it. I did

CoolWhiteVR6

· #18 · Feb 15, 2002

Re: What do my DTC Codes mean (GmanX)

quote:[HR][/HR]yep I had that code. Bad MAf was the cause. Call VW get the to pay for it. I did[HR][/HR]

Thanks for clarifying that you had the same code. http://****************.com/smile/emthup.gif What was your approximate milage when VW paid to replace your MAF?

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GmanX

· #19 · Feb 15, 2002

Re: What do my DTC Codes mean (CoolWhiteVR6)

I think it was around 51k or 52k or something like that. Defintly out of warranty

CoolWhiteVR6

· #20 · Feb 20, 2002

5

Re: What do my DTC Codes mean (adg44)

quote:[HR][/HR]#3 makes me think either your MAF is bad or an O2 sensor is bad. http://****************.com/smile/emthup.gif
Let us know what you find out. [HR][/HR]

My car was in for diagnostic work today at Osborne VW here in Denver. Actually my second trip there. The first time on Monday. They pulled the code, but couldn't find anything wrong.
I just got off the phone with Travis at Osborne http://****************.com/smile/emthup.gif
Code 17978: After spending most of the morning with the second round of diagnostic, the MAF came out of spec to the point it was deemed necessary to replace. The cost of a new MAF and labor is ~$500.

I'm at 56,000 miles. As mentioned earlier in this thread, the emissions warrenty is 50k. Anyhow, Travis told me he had already talked with VWoA. VWoA agreed to cover my MAF replacement (parts and labor) as part of a "Good Will Warrenty."
VWoA http://****************.com/smile/emthup.gif
Travis at Osborn VW http://****************.com/smile/emthup.gif
I'll be picking the car up after work today. And of course, I'll post to this thread again if the CEL comes back on in the next few days.

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