CEL and BLINKING GLOW PLUG LIGHT(Long Post)

After searching the forums I only found 4 topics of which one involved MODS. Below are postings from these topics:

Have them replace the glow plug relay. A blinking glow plug light WITHOUT a Check Engine light indicates a problem with the glow plug system. WITH a Check Engine light would indicate that a malfunction has been detected and a "stored" fault code can be found in the ECU memory. (As opposed to a "pending" code, which just means that the ECU has detected a possible problem and is looking for "confirmation" before it starts flashing lights. "Pending" codes can be read with a scan tool, but no warning is given to the driver.)

I made it home and it didn't blink! The service advisor didn't give me the right story. It says here on the "invoice" that the brake light switch was intermittent (using scan tool found a sporadic code 00741-brake light switch) and the switch was replaced, problem solved...so far. I wonder why only 0.71 labor on the invioce? Can they only charge VW a flat rate to change out the switch, and not charge for troubleshooting time? Anyway, for those interested, the part number of the switch is 1J0-945-511-A.

In this case, it was a brake light switch. As mickey said later, the lights are for emission controls, and not for diagnosing problems. Then I was reading the other story:

Got my car back from VW last evening, and am no more educated than I was last week. All they could tell me was that "something" was wrong with the Diesel injection pump, and so they replaced it. Couldn't tell me anything of the nature of the problem, since they just replaced the part without exploring the situation further.

In this story many mentioned about draining the fuel filter to get the lights to shut off. And now is my full story. 1998 NewBettle 41,000. Bought used at 38,500. At first I noticed the tripometer would reset without me hitting the button. Then one day the radio went into safe mode, and the CEL came on. I did the fuel cap magic, and checked the oil, and filled up with amoco premium blend, and threw in some powerservice. The CEL went away for about 300-500 miles. Two weeks ago, the CEL came on and stays on after you start the car, and it idles for a minute or so. Now today, driving down the road, shortly after the blue temperature light went out, the glow plug light started to blink. These stories have only given me one priority, that is to drain the filter as soon as I get back to me car. However, it may be the Glow Plug Relay from what is said in the FAQ. Now I checked the metal fuse on the battery and that is ok, but where the hell is the GLOW PLUG RELAY? The one fuse box is on the left side of the dash, in which you can only get to it if the driver side door is open. Where is the other fuse panel?

That is one question (cause the bentley is not clear on the location). The other thing is about the fact if my BATTERY could cause the problem. With my power loss problems, it was recommeneded to check the wire harness for coolent (where is the harness??) and check the battery. I have been reluctant to disconnect the battery because of these other problems and what happens to the resulting codes. So I hope this is enough info, here are my questions
Where is the other fuse panel where the Glow plug relay resides?
Is draining the fuel filter the miracle cure for the blinking glow plug light. Should I go ahead and disconnect the battery and test it even though all these other things are going wrong and it may/or may not(dont know) reset the trouble codes??

So, you never changed your battery....
It's 4 years old and you're suffering brown outs and you don't want to come up with the $50 for a new battery? Maybe that low voltage that you've been running with fried something by now.
(I'm really not a wise ass but I would have thought you would've changed the battery by now.)

I think the codes are retained even if you disconnect the battery, but I'm not positive. You might need your radio code, but I didn't when I had my 2000 NB's battery disconected for a week.

The glow plug relay is near relay 109 underneath the driver's side lower dash panel cover, I believe. I think it's around $300.

Tripmeter resetting upon engine start-up means low voltage, and that's happening for a reason. As noted above ... the first suspect is the battery!

Low voltage throws all sorts of things out of whack on electronically controlled vehicles - sometimes permanently!! Don't worry about disconnecting/reconnecting, it's not a problem. You might lose the tripmeter reading, the time on the clock, radio station presets, and other relatively unimportant stuff. Fix it NOW, before you fry something!

One other tip, when you have the battery out, check the chassis ground connections located underneath the battery.

You guys are so nice

Do not beat around the bush, just punch me in the face and tell me CHANGE YOUR BATTERY

AGREED. I am checking with the dealer, blindly, to replace the battery(they have been good about anything I have found wrong with my used car). However an UPDATE, draining the fuel filter and starting the car back up blew out some smoke and then ALL LIGHTS WENT OUT. I will get the battery I was going to get the new battery but I wanted to see if my CEL and BGPL were electrical or something more serious. I believe I am cool, I will relive this topic if no one has BRIGHT opinions to give me

Oh forgot to mention velvet foot.

I just got the car used, so thank the previous owners . This and the fact they killed the AC. Imagine that, a black car in the summer with no AC. (Dealer looking at it)

I gave you the opinion back on April 5th that it could be the battery. It's 4 year's old and maybe not maintained!

http://forums.tdiclub.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=3&t=007459&p=

I know, Married with kid and my wife and I run two cars to work. Its new to me but I am getting better with the time I have. Battery is going to be 59.99, not so bad. Will keep you posted.

This post to velvetfoot.

I am going to do the battery tonight this is 5/1/02. However I posted that everything was cool. Even after draining water out of the Fuel Filter, the CEL is on and the GPL is blinking again. The battery will hopefully be the cure to this problem. And Gofaster, you were saying to check grounding when I take the battery out, where else should I check, someone mentioned the wiring harness, is this under the battery??????

It's not a good sign that you're GPL is blinking. I don't think a glow plug relay will kick off the GPL. It seems that you should get the error codes read as well. Hopefully it's the brake switch, a $10.00 item. You could be throwing $ at this though, without getting someone with a vag tool and with the expertise to interpret it.

I should do the battery first though, do you agree? then worry about what codes are produced?

I agree. It's 4 years old, and not wicked expensive and so you'll need one soon anyway no matter what. Afterwards, maybe you should read and clear those codes and see what comes back. If it's running well and you still have that blinking GPL, perhaps it's only the brake switch. Perhaps you could hook up with a Fred'ite in your area. I think they GTG's in MD as well.

To Velvetfoot

I ran the current draw, and open circuit test on the battery and it was a steady 12.7V and only drawling 300mA.

Its just horrible, now we can narrow down (I hope) before this car goes to the dealer. Its not the glow plug relay, cause I would be drawing more current if it was. Also, (AT least the malfunction) could be a GLOW PLUG itself. I tried testing the Glow plug bus but I could not find the ground point. It was ready some voltage, but I was in a rush and did not know what voltage the glow plugs have when you take of the temperature sensor Will have to buy some G12 too Everything else on the car is normal. And looking in the car i understood what Gofaster was talking about under the battery and checking for grounding since all the damn wires run under it. I have posted for VAGCOM help in two places. I am not sure if anyone will be able to help me before friday.

Beetle is at the dealer tonight. Tomorrow we will see if they are a GOOD service shop. More details later. When this is said and done, it will be a good FAQ for ODD Problems.

Will someone explain to me the point of draining the fuel filter when the glow plug light blinks?

The glow plug light is used for many things, only one of which has anything to do with glow plugs.

Problems with the injector pump, perhaps caused by water in the fuel, could cause a blinking glow plug light. That's what I heard anyway.

In the owners manual, you are told to do it if the glow plug light is blinking. "Pull off the side of the road, draing the fuel filter, then TAKE YOUR CAR TO AN AUTHORIZED VOLKSWAGEN DEALER."

EPILOGUE:

So here is what the dealer tells me. The CEL was for sporatic voltage (Thanks for the correct input Velvet because there was probably a few codes from the earlier instance). When I drained my fuel filter, the car did not start afterward. So a person was there helping me, offered a jump, I was like "Why not", and eventually it turned over blowing NICE SMOKE and then the engine RAN GOOD. So in this case, I AM SURE draining the fuel filter was the right move with the Blinking GPL, however, it boils down to the defective battery or a grounding problem. Remember early I posted the battery tested fine. I will deal with this as a seperate ISSUE, and close this, another crazy story in the life of a turbo-diesel. MORALE OF THE STORY: Any electrical problems can lead to Check Engine Light, and Blinking GLow Plug Light. (Notice neither light had anything to do with the problem, just their as FAULT INDICATORS)

You have to be *&#%*# kidding me.

Drive the car several miles everything is cool, then get home, right before I get home, rev it alittle. Guess what. Glow plug light starts blinking.

Well was talking with my dad, and anybody in the forum back it up. If a glow plug is bad, it will draw alot more voltage????? Not sure if this is true or not. But tomorrow I will test out resistance of glow plugs, if that checks out and none are bad, I will check the bus, then (AS SCHEDULED) will get a new battery, and check GROUNDS and the wiring harness.

Originally posted by weedeater:
Will someone explain to me the point of draining the fuel filter when the glow plug light blinks?

The glow plug light is used for many things, only one of which has anything to do with glow plugs.

Click to expand...

<font size="2" face="Verdana, Helvetica, sans-serif">This dates back to some early model 1.6L diesels. On the belly of the car they had installed a water seperator with a water sensor. If the glow plug light started blinking you were to pull over get a small plastic bag from the spare tire tool kit and drain the seperator. The system worked great and I actually had it go off a couple of times during the time I owned my previous Golf.

The newer TDI's obviously do not have this function and anything blinking on the dash is a "code".

DB

On my 2000 Jetta the glow plug light flashed when both brake light bulbs went out. Also the center light was dimly on all the time. I replaced both bulbs and the GPL stopped flashing and the center brake light went off (except when brakes are depressed.) Hope this helped.

Thanks, DBW. I was about to say that about the water sensor. But knowing that a water sensor hasn't been a part of these cars for some time, I couldn't see why anyone would drain the filter (completely??? ) when the glow plug light flashes.

LS: you have to get it out of your mind that a flashing glow plug light has anything to do with the glow plugs. On gas VWs, this light has a different name and is used to indicate other electrical problems (like a burnt out tail light) that don't mean 'take it to the dealer RIGHT NOW'. For TDIs, they reused the lamp rather than add another one strictly for glow plugs.

I will tell you all, because this is an electrical problem, I will start by testing the glow plugs to make sure they are not bad, and I am going to put in another battery. They just cleared the codes, did not replace the battery. While I am changing the battery, I will check for a good grounding connection running from the negative battery cable. The fuel filter needed to be drained and needs to be replaced as per the maintanence schedule. So that is good for the injector pump, but now need my lights to STOP BLINKING, THEY ARE BLINKING AND FLASHING AND FLASHING AND BLINKING AND FLASHING AND....OH

Bonus points to who knows what movie this is from.

Well everyone keeps telling me "Do not assume that the malfunction light has anything to do with the glow plug system". However, The GLow plug light blinks, before I turn the car on. Now when I do the current draw test, wouldn't that test for a BAD GLOW PLUG RELAY???? Mickey stated if I have a lone gpl blinking, its something in that system. Dealer said CEL and GPL were from loss of power, however, not telling me S*** about the problem. So today I will just test the glow plugs, if they test ok on resistance, i will run the voltage test on the bus, if that tests ok, then I will put in my new battery, and leave this at that. If it is a glow plug, or anything else in the system, good time, since its GETTING HOTTER here. AFTER I DO ALL OF THIS, I will need a FREDITE with a vag com because i can trust them better then the dealer. However the fact that I drove it for 5 miles and no light, then it comes on after I stop, maybe its the brake switch. Will post after all this nonsense, and could someone please tell me where the VAG/COM list is?

hello there is few thing the glow plugs harness is probably in trouble there is 4 wires and the dealer twist all together i don t now if this is your problem but it was mine if not check the ground under your battery it is probably corroded or the relay 109 .anyway if your are not sure about the 109 relay just e mail valois he can help you...(the wirring for the glow plug is a vw recall)

[ May 06, 2002, 15:44: Message edited by: boucanier ]

just 1 moe thing i will be at jake place the week end of the 20 with my tool and my vag com and even a lap top for sale if you whant ..jake place is about 160 miles from your place he lives in forked river nj if you whant to come it up to you.

check this topic:http://forums.tdiclub.com/NonCGI/ultimatebb.php?ubb=get_topic;f=25;t=000111