How To extend glow time with Vag-com - ALH

If I understand the workings, the gps are on when the rpm's are under 2500 rpm until up to a reasonable temp (somewhere near normal).

Which is why "shift at 2500 cold" to keep the gps on for the "afterglow".

I don't know about other models but on my 2003 the coolant plugs stay on until I hit 100F or 37C. I tried running the RPM up, it didn't matter they stay on until they hit that temperature. Even in the middle of summer they will run until they hit 100F, again the stock setting is about 70F on the coolant plugs.

Ooops - I didn't read the "coolant" part of "coolant glow plugs". I'm sure the coolant gps are on until it hits whatever temp the ecu is set for. Sorry for my misreading and misleading post.

Brock_from_WI said:

I don't know about other models but on my 2003 the coolant plugs stay on until I hit 100F or 37C. I tried running the RPM up, it didn't matter they stay on until they hit that temperature. Even in the middle of summer they will run until they hit 100F, again the stock setting is about 70F on the coolant plugs.

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Are you saying that on your car after you did the "extend glow plug time" adaptation for the cylinder glow plugs that the cooland glow plugs now stay on until a higher temperature?

Yes, once I adjusted the starting glow plug time it made the colant plugs stay on longer as well. My guess is this mod is basically telling the ECU the engine is cooler than it really is.

I tried this mod in the past...didn't really see a difference in starting ability or smoke.

This week I started at 3F and it glowed for about 10sec (normal adaptation) and smoked for about 3 sec after starting but then ran fine.

I guess the GPs are still in good shape although original after 135k/11yrs.

I'm sure this mod will work for people with weak or 1 bad GP until they get it corrected.

Coldest I have started was -22F, not too bad for PA!

2006 A5 Platform

Hi guys great thread!!!!! will this work on the 2006 Jetta? I cannot seem to make it work. Keeps on saying that channel 12 is not available.
That been said is it even possible to adjust the glow time on the A5?
minus 23 the other day and the indicator light went out after 3 seconds.
And no it did not start.........well it did eventually, but it was not pretty.

When I got the coolant temp from the Vag-Com it says that the glow time for the plugs with the coolant temp was only 1.6 seconds and this was also a -0.9 degrees celsius.

No. Your car has ceramic glow plugs, just like the 2004+ A4 cars. The glow time can't be extended. Are you sure your coolant temp sensor is working properly?

Now the availability of replacement ceramic plugs is another debacle...

-Jason

Thanks for the info.....I have hooked up the Vag-com and looked at what the coolant temperature is, and it matched up with the outside temp.
Is there a more in depth check that can be done? where exactly is the sensor on the A5 pd engine? it has been suggested to unplug it to see if the glow time extends any longer.......is this a valid test with the A5?

Lug_Nut said:

Re questions about 1Z adaptation:
Depends on which ECU is installed. The original North American market 1996 Passat TDI ECU (with the BK suffix after the part number) does not support this adaptation. The 'smoke fix' replacement ECU (GQ suffix) might. The 1997 and later FA Passat and JB Jetta do allow this adjustment.
I've added a manual over-ride to allow me to power the glow plugs for as long as I hold the button. My BK doesn't allow adaptation. More importantly to me, the high percent of biodiesel I choose to use can benefit from heat assist at an ambient temperature where petrodiesel might not need and the stock ECU program doesn't activate the glow plugs.

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Would this apply to a 1995/6 AAT? I can't find the correct channel to adjust it and I do have the problem of having to crank for ages (sometimes a 2nd battery) to get it started.

Cheers
MG

The AAZ engine (turbocharged, cable operated pump, no intercooler) has a separate time module installed in the fuse and relay array. There is no ECU per-se in that model to which a similar software tweak can be made.
The AAZ has a mechanical cable in the dash that the operator can pull to operate a "cold start assist", sort of like a choke on a gasser, to change the fuel delivery and timing, but the glow plug timer in the AAZ is initiated by opening the driver's door with, I believe, just one temperature input (so the glow plugs don't come on in the hot summer months).
Other than installing a manual override pushbutton to allow the operator a level of control, there are no 'automatic' manipulations possible.

Today I changed the glow plugs when the ignition.
The question is, what parameters to change the engine, if we did it extend the period of glow plugs?

Glow plug

hey guys i got a code that is saying "cylinder 3 glow plug circuit /open" i have checked all the glow plugs and they all work but the code still comes on any one have any idea what i can do?

I respond to someone, please, to post #104 ?

The parameters are stated in post #1.

If this request is in reference to your intent to reduce the glow plug operation after starting, (as you request in your other posts in other threads), understand that this change of computer setting will also have an effect on the temperature at which glow plugs operate before starting the engine.
If you are considering changing the computer value to turn off the glow plugs after the engine is running, you need to know that that change will also change how long the glow plugs operate before starting the engine, and also change the temperature at which they become active.
You might find that to have sufficient glow plug operation before engine start requires you to have some mandatory glow plug operation after the engine starts. I don't believe the pre-start and post-start glow plug operations are separately adjustable.


I can't believe how long I searched to find this thread!
of course,I get easily sidetracked.....

Well, my latest A3, with ED series ECU, is now adjusted from 32768 to 32750 and the glow plugs are cooking before cranking which is a big help with B100 on a 35F morning!
A3 and B4 TDI controllers identified so far:
AT: (euro and aussie) adaptation not supported
BK: (North American 1996 B4) not supported
ED: (1997 A3) supported
FA: (1997 B4) supported
GQ: (replacement for BK) supported
JB: (1998+ A3) supported

The EB computers used in the 99.5 golf / jetta support it. Seems like all EDC15 comptuers support it, but the older OBD1 era EDC12 ones do not.

-Jason

When I try to logon with the 12233 it always gives me an error.

Catlin987987 said:

When I try to logon with the 12233 it always gives me an error.

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Do you have a registered version? I think that could cause that to happen.

mmm, no, but I am trying to convince the wife to let me order it this week.

GP System Diagnosing

Hi guys, thanks for the info in this thread! Couple things that I can't wrap my head around.

I have a 99.5 ALH (Bone stock ECU) and having problems with GP "ON" time. They will NOT stay on for longer than a second even in 0-32*F temps. No GP codes current or stored, replaced the GP harness recently (previous owner ruined the old one), all GP's at .6ohms, and even installed a new coolant temp sensor (OE VW) as I was getting abnormal gauge readings. I haven't pulled the GP's to check for soot/abnormal wear and I don't think they were ever replaced. Also checked coolant temp with VCDS and it is around 79-80*C just below the 190*F level on the cluster. I haven't checked the temp when cold yet as I usually have to drive somewhere to access VCDS. I have to unplug the CTS to get it to start normally and I get around 10 sec of glow time and lots of "after glow" below 2500rpm for about a minute or so.

Ultimate question: Will this adaptation affect "cold" glow time, or does it only apply to glow time after the cold-warm "threshold"?

The adaptation increases both the threshold at which the plugs start to glow AND increases the length of the glow in relation to the temp.

So, if your car glows for say 1 second at around 0*C for example, it should glow for 3-4 seconds after the adapation at that same temp. Likewise, if you had no glow at all at say 5*C, you should get some glow at that temp after the adaptation.

I should also mention that if you have a 99.5, there are 2 coolant temp sensors. One in the housing on the head and one in the upper radiator hose. One controls the temp gauge and the oher sends a signal to the ECU to tell it how cool/hot the coolant is. These 2 sensors were combined into one 4 pin sensor on the 2000+ cars. So its possible your poor cold starts are still caused by one of the CTS's being faulty if you only changed one.

Thanks for the clarification Wingnut! I'll do the adapt. change when I can get someone with VCDS or $350...

I replaced this CTS on the coolant flange attached to the head. It is a 4pin rectangular socketed sensor that I thought controlled both gauge and ECM input? When unplugged the gauge ceases to operate and GP time is increased to the max. Also get a CEL and code for CTS ckt, so my thought is that the ECM looks for the sensor for injection quantity/timing input. I thought that the sensor in the coolant hose was to control the hi/low cooling fans turn on point?

*I've also come to the conclusion that I have a bastard car and an obsession for odd year vehicles, so weird stuff is not uncommon to me - like my 1984.5 Sportster that they only made for a half year and is hard as hell to find parts for!

I thought i would bump up this thread for the time of year it seem appropriate. My Golf has the hard start at around 40 problem, timing and compression are good, coolant sensor is new. I will be trying this in the AM.
Great info wingnut.

Wow i need to have this done my GP do not seam to come on at all till 40F i have a long cranking time sometimes when i am just above that temp.

Did mine and made all the difference.

TDI32 said:

Wow i need to have this done my GP do not seam to come on at all till 40F i have a long cranking time sometimes when i am just above that temp.

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Your gp's are working as designed - you have another issue with respect to hard starting.

Error: Channel 12 Not Available

Hi Guys,

I have been trying to modify my glow timing settings as per Wingnut's method, however I am unable to access Channel 12 (Error: Channel 12 Not Available), even after logging in with the 12233 code. In fact the only channel I can access is Channel 02 (Idle speed). I have only just purchased a legit Ross-Tech VAG-COM unit, so I may be making a rookie error, however the install and registration process went smoothly. Anyone able to throw me a bone on this one. Cheers.