Check engine light on runs fine.

tfromt

Member
Joined
Mar 7, 2003
Location
Tampa,Florida
TDI
pl gray 2010 jetta
My check engine light came on but the car runs fine. Any ideas what the cause is. I am taking to the dealer this week to have it checked out.
 

ymz

Top Post Dawg
Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
>>I am taking to the dealer this week to have it checked out.<<

The dealer will probably charge too much to read and to fix whatever is causing the CEL...

Try going to AutoZone to get the code read, and then post the result up here...

If you haven't yet made the acquaintance of Keith Scarborough, please try to do so... He's our regional TDI expert, and if you can find him when he has some time available, I assure you he'll take far better care of your car than the dealer will !!! His UserID here is LWB053

All the best,

Yuri.
 

ymz

Top Post Dawg
Joined
May 12, 2003
Location
Between Toronto & Montreal
TDI
2003 Jetta TDI Wagon, 2003 Jetta TDI Wagon
If I had to guess, I would say your CEL is most likely on account of a glow-plug... either corrosion inside the harness, or an out-or-range glow plug... (another popular problem at your milage is coolant temperature sensor)

I doubt this would be covered under the power train warranty, but it never hurts to ask...

(Typical dealership follow-up to this is on the order of $75 to scan the car, and if it's a glow plug fault, replace all 4 glow plugs, and possibly the harness as well...about $400... If you were to find out what the problem is - AutoZone or a local TDI-Club member with a Vag-Com - and you need a glow plug, one of our suppliers here, Danix, is having a promotion on 4 Beru GP's, shipped for $60, I believe... the dealership price will be on the order of $45 each...)

Please drop into AutoZone and at least get the code read (for free!!!!)...

Yuri.
 

WDM

Veteran Member
Joined
Aug 19, 2005
Location
B.C.
TDI
Jetta Mk IV Wagon/2005/Reflex Silver
After 2300km on my new Jetta Wagon I got a CEL one morning which freaked me a bit. Took it to the stealership, they said just drive it unless it flashes and make an appointment if it stays on. Had the code read at a local mechanic recommended through these forums and it was a common GP fault. In the meantime I just drove it waiting to take it to the stealership the next week to have it diagnosed. Two days after it came on it went away and I had since learned of DeoxIT spray and just how common this minor problem is with these cars.

Sprayed my GP harness with DeoxIT, it reacted immediately (like Hydrogen Peroxide on an infected wound). I drove it for the day, re-sprayed it again without any reaction and haven't seen the CEL since. If my brand new GP harness was obviously oxidizing I would hazard a guess that you have a similar problem unless one of your glow plugs actually is bad or your harness is beyond simple fixes like mine. Might be worth a try just treating your harness with DeoxIT or a similar product and seeing what happens.
 

LarryLymb

Veteran Member
Joined
Apr 13, 2002
Location
Lehigh Acres, FL
TDI
Jetta TDI Wagon 2003 Mojave Beige, 5 speed
My CEL light was diagnosed as a bad fuel temp sensor. The dealer replaced the fuel injector pump under warranty. A $30 part would have solved the same problem.
 

LWB053

Vendor
Joined
Aug 5, 2003
Location
Tampa, FLA, USA
TDI
2000 Jetta, Dk Green
Larry, any chance you have the original fuel pump?


tfromt, my contact info is in my profile. I'd be happy hook a VAG-Com up to your car and let you know what the problem is. I'll be doing a TB change in my garage this Saturday if you'd like to drop by...
 

LarryLymb

Veteran Member
Joined
Apr 13, 2002
Location
Lehigh Acres, FL
TDI
Jetta TDI Wagon 2003 Mojave Beige, 5 speed
The dealer sent the fuel pump back to Borsch for exchange. Borsch wanted to know why the sensor were going bad. McBrew replaced his sensor. Have great success on the TB change! I appreciate the invite but 4 hours of drive a bit much with Wilma coming.
 

Borborygmi

Veteran Member
Joined
Nov 13, 2002
Location
Cedar Park, TX
TDI
2003 Jetta Wagon
There is really no way to guess what the CEL might be. Glow plug problems are common. It's unlikely anything that will break the engine. Autozone might help. The stealer will gouge you for 5 minutes work to read the code. Just unconscionable. It doesn't take two of those to pay for a VAG-COM.
 

LWB053

Vendor
Joined
Aug 5, 2003
Location
Tampa, FLA, USA
TDI
2000 Jetta, Dk Green
Not to mention the fact that the dealer will want you to drop the car off sometime next week, and they'll call you in November when they have a chance to look at it...
 

Miyagi

Member
Joined
Mar 2, 2005
Location
Sacramento area, CA
TDI
01' Golf GLS 4-dr
My 2001 Jetta GLS has a CEL that came on a few weeks ago, but the car drove fine. Then the glow plug light came on shortly after starting the car. One of the two began to flash, so I took it to Las Cruces, NM dealership. They found a glow plug preheater wire (is this part of the GP harness you guys are referring to??) that appeared to be cut. (Morrris Auto Group VW in Anchorage, AK was the last place I took it to, suspect they are up to no good.) Well, Las Cruces repaired the wire, saying a new wire set/harness would cost me $600, so this simple wire repair may work. It did, but now the CEL is back. Car still drives fine.
I'll see if the local Autozone can scan it, but those of you with VAGCOMs, what does it cost and where's good place to buy them? Also, any other ideas why the CEL keeps coming on? The previous time (9 months ago) it was a MAF gone bad. The car now has about 63,000 miles.

Miyagi
 

bhtooefr

TDIClub Enthusiast, ToofTek Inventor
Joined
Oct 16, 2005
Location
Newark, OH
TDI
None
http://www.ross-tech.com/Merchant2/merch...ory_Code=VAGCOM - $99 (you'll have to download VAG-COM. That's to get a serial number to unlock everything)
http://www.dealz4all.com/product_info.php?cPath=23&products_id=41 - $27.88

Or, you could get a cable with the VAG-COM. However, that'll be a much cheaper solution, doing it that way, with the cheaper cable from another supplier. Note that that cable requires a serial port, which newer laptops don't usually have. Ross-Tech recommends a PCMCIA serial port adaptor, and NOT a USB one.

Note that I have never used VAG-COM, and don't know about the quality of that cable. This is just from checking the Ross-Tech site, and googling for cheap cables.

The VAG-COM software itself is only sold by Ross-Tech, as they make it.
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
All purchasing info from the source of Vag-Com can be found here.

The CEL is likely related to the glow plug system - could be a gp itself is bad, could be the wire splice that was put in is mimicking a bad gp, could be dirty contacts between the gp harness and the gps themselves.

Get the CEL codes pulled and report them here so we can guide you as to what the problem may be.
 

Miyagi

Member
Joined
Mar 2, 2005
Location
Sacramento area, CA
TDI
01' Golf GLS 4-dr
rdkern,
Autozone scanner came up with one code:

P0380 Glow plug/heater CKT A Malfunction

Guessing the wire repair they did isn't holding up. Is there any other place besides the dealership to get a new wire harness?
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
Try world impex

When I saw this like - the harness was about $30 - possibly a tad more with shipping.

You may not need it - I'd suggest you start by cleaning the connections between the harness and gps, check the ohms of the gps themselves, and check to see if you have power at the connectors. Isolate the problem, then repair the parts that are not working. Find Wingnuts Glowplugs 101 thread - it's worthwhile reading for you at this time.
 

DSL HED

Veteran Member
Joined
Aug 14, 1999
Location
S. Portland, Maine
TDI
2012 Jetta wagon DSG
I'd recommend cleaning the GP harness with Deoxit D5. My wife's 2000 Jetta had a check engine light that was on steady, so I connected VAG-COM and got the Glow Plug intermittent code. The car ran fine and all the plugs checked out for proper resistance so I ignored it most of the summer. The car needed to be re-stickered, and since I live in the one county in Maine where they do "enhanced" testing, I had to make the CEL go away. I sprayed the harness with the Deoxit, waited about 15 minutes, and sprayed it again, and the code hasn't reappeared yet. Thanks to Wingnut for the great glowplug how-to.
 

Miyagi

Member
Joined
Mar 2, 2005
Location
Sacramento area, CA
TDI
01' Golf GLS 4-dr
Just to make sure I'm spraying the right part - you pull the boot off the glow plug, then spray inside the boot?

I've run the entire procedure from Wingnut's GP 101...everything checked out fine, and the CEL is still on. The Jetta has 63,000 miles, is a 2001 with manual 5 spd. Is it possible that the fault light just needs to be reset? Or will the CEL just not go out until the problem is fixed?

Does to P0380 code mean that it could really be anything (GP, coolant GP, relay. etc)
 

yosemitesamiam

Veteran Member
Joined
Mar 15, 2003
Location
Colorado Springs
TDI
01 Golf, 02 Jetta
HA...you and I both. Just got done scanning mine. Fault code P0380 -Glow Plug/Heater malfunction. Being listed as Intermittent. Too bad I live in Southern California...if I lived anywhere else, I might have to replace it!
 

WDM

Veteran Member
Joined
Aug 19, 2005
Location
B.C.
TDI
Jetta Mk IV Wagon/2005/Reflex Silver
When I spoke to my local mechanic (a member on the forums) about the GP harness and contact cleaner he suggested that I also use some dielectric grease after treating the GP harness with DeoxIT. Got a tube and put a small dollop on the head of each glow plug then put the harness back in place. Did the same with the coolant glow plugs also. This prevents corrosion after cleaning with the contact cleaner.
 
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