www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2014 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You



Go Back   TDIClub Forums > TDI Model Specific Discussions Areas > VW MKIV-A4 TDIs (VE and PD)

VW MKIV-A4 TDIs (VE and PD) This is a general discussion about A4/MkIV Jetta (99.5-~2005), Golf(99.5-2006), and New Beetle(98-2006). Both VE and PD engines are covered here.

Reply
 
Thread Tools
Old October 14th, 2012, 11:12   #1
freakwithracket
 
Join Date: Oct 2010
Location: Columbus, OH
TDI(s): 2003
Fuel Economy: 50.57mpg
Default Manual Glow Plug Switch

For whatever reason, my glow plug system does not work correctly. I have tested just about everything, plugs, harness, CTS sensor, swapped out the GP relay and ECU, and the GP light stays on for only a second before going out, even with the CTS unplugged. So I think I want to wire up my glow plugs to operate manually. I want to install a cabin button to activate them. Does anyone have any insight on how this could be accomplished while not causing a CEL? I have searched but not found much information on this.
freakwithracket is offline   Reply With Quote
Old October 14th, 2012, 19:53   #2
xyfzrider7x
Veteran Member
 
Join Date: Sep 2012
Location: mount union,PA
TDI(s): 2000
Default

Thy dont stay on very long at all even on cold mornings mine only stay on for 2 or 3 seconds
xyfzrider7x is offline   Reply With Quote
Old October 15th, 2012, 06:47   #3
freakwithracket
 
Join Date: Oct 2010
Location: Columbus, OH
TDI(s): 2003
Fuel Economy: 50.57mpg
Default

Thanks for the post. The question here is not how long they should stay on. When its 5-10 outside they should definitely stay on for more than 2 seconds by the way. The issue is that no matter how cold (even 0) they do stay on for more than a second, if they are even actually on. I am about done looking for the issue, and just want a manual setup.
freakwithracket is offline   Reply With Quote
Old October 15th, 2012, 06:52   #4
40X40
Experienced
 
Join Date: Feb 2006
Location: Kansas City area, MO
Fuel Economy: TBD, new data forthcoming
Default

Is the light intended to stay on as long as the glow plugs are operating, or is the light going out an indication of 'ok to start'? IDK.

Go see a guru.

Bill
__________________
www.IHMSA.ORGhttp://www.youtube.com:80/watch?v=Xtsxt7xgbpc
If you omit pertinent info from your question, you cannot reasonably expect a good answer.//Not affiliated with any vendors except as a customer.// Wise people lurk more.// I'm not a guru.// 'I got actual real friends in the real world'-T'sTDI/ If you were the only entry, there wasn't a race.// Grammar and spelling really are important, but I don't claim to be good at it.// Typical drivers can't.
40X40 is offline   Reply With Quote
Old October 15th, 2012, 08:50   #5
turbocharged798
Veteran Member
 
turbocharged798's Avatar
 
Join Date: May 2009
Location: Ellenville, NY
Fuel Economy: 40-50mpg
Default

The light just mean OK to start, it does not necessarily run with glow plug operation.

If the light is not staying on when you unplug the CTS, then the ECU is not seeing the correct temp. If the ECU is not seeing the correct temp, then you will have a lot bigger issues than the glow plugs.

At that point, I would connect VCDS and see what the ECU is reading for coolant temp when the CTS is unplugs. It should be something ridiculous (-40*F IIRC).
__________________
99.5 Jetta TDI; DLC1019 nozzles, G60/VR6, ASV .5mm pistons, PD100 rods, Malone Econo tune, EGR delete, ASR/EDL, bilstein TCs MFA cluster, e-codes,rally armor mud flaps. Beater car. 325K miles.
04 Jetta TDI . MFA cluster, e-codes, reverse light mod, LED trunk light. 180K.
turbocharged798 is offline   Reply With Quote
Old October 15th, 2012, 08:59   #6
n1das
Veteran Member
 
n1das's Avatar
 
Join Date: Jun 2002
Location: Nashua, NH, USA
Fuel Economy: Who cares? It's a DIESEL! Great fuel economy comes as a bonus!
Default

Quote:
Originally Posted by 40X40 View Post
Is the light intended to stay on as long as the glow plugs are operating, or is the light going out an indication of 'ok to start'? IDK.

Go see a guru.

Bill
I second Bill's recommendation to go see a TDIclub GURU in your area.

I'm not a guru but I'm somewhat familiar with the GP behavior. On 2002 and 2003 TDIs (ALH engine), the GP light is an OK to Start light. The GPs actually stay on up to about 10 seconds longer if you wait longer. There is no need to cycle the key to get extra glow time.

The 2002s and 2003s have a 4-wire GP harness and a solid state GP relay. You won't hear this relay click because there are no moving part(s) inside and the relay is located under the windshield wiper cowling. IIRC, the change from the older 2-wire GP harness to a 4-wire harness was due to changes in OBD-II requirements which now require individual monitoring of system components (can't monitor components as a group).

Older TDIs prior to 2002 (not sure about 2001) had a 2-wire harness and a mechanical GP relay. IIRC, the GP light on the dash showed when the GPs were actually ON and you could hear the GP relay click on or off.

In my 2002 Golf TDI (sold it in 2010), one trick I would do in the bitter cold weather was keep the driver's door open when I turned the key. Keeping the door open was only to keep the interior lights on while starting the car. When I first turned the key to ON for GP operation, I could see the interior lights dim slightly while the GPs were ON. The GP light on the dash went out but the GPs remain ON for up to about 10 seconds after the GP light goes out. I would hit the starter the instant I see the interior lights brighten back up when the GPs finally turned OFF. This helped starting in below zero F conditions because the GPs stayed hot long enough and lightened the load on the battery during cranking.
I thought about doing a mod to wire up a light to the GPs so that I have a "real" GP light to know for sure when the GPs are actually on or not. I never bothered with the mod because I stayed on top of maintenance and never had any cold start issues with the car during my 8 years and only 361k miles of ownership.
__________________
David Sterrett, N1DAS
2014 BMW (F10) 535d XDRIVE ///M-Sport, 255hp & 413 ft-lbs of AWD stomp 'n go fun!
2012 BMW (E70) X5 XDRIVE35d, 265hp & 425 ft-lbs of AWD stomp 'n go fun!
n1das is offline   Reply With Quote
Old October 15th, 2012, 09:53   #7
Vince Waldon
Veteran Member
 
Vince Waldon's Avatar
 
Join Date: Apr 2009
Location: Edmonton Alberta Canada
Default

Quote:
Originally Posted by n1das View Post
IIRC, the GP light on the dash showed when the GPs were actually ON and you could hear the GP relay click on or off
Not intending to be picky here... just commenting for clarity.

I've a 2001 with the old-skool relay and I added an LED on my dash connected directly to the glow plug harness. I can confirm that the factory LED in the cluster is independent of the glowplugs actually having power... so more of a "OK to start" LED as well.

The other thing learned with my extra LED is that those pesky glow plugs run all the time, summer or winter, for up to a couple minutes *after* the engine starts. Emissions and driveabilty I'm told.. but it does help me understand why people get P0380 codes in the middle of Florida.

When they are in after-run mode they go out whenever the engine goes over 2500 RPM...which makes the relay click on and off as you run thru the gears.
__________________
Vince Waldon
Edmonton AB Canada
2001 silver TDI Jetta, Malone Stage 1.5
2001 blue TDI Jetta, Malone Stage 3. Grrrr baby... very grrrrrrr!
1970 Bay Window bus... not so grrrrr
Vince Waldon is online now   Reply With Quote
Old October 15th, 2012, 11:07   #8
freakwithracket
 
Join Date: Oct 2010
Location: Columbus, OH
TDI(s): 2003
Fuel Economy: 50.57mpg
Default

This is reposted form another thread of mine. I am not just re posting, I just want to avoid much of the normal "my glow plugs don't work" suggestions that I have already tried. So a question abut the LED, did you just use a scotch connector or something on one of the harness wires? I think that could be incredibly helpful. I have LEDs in the cabin now, and its difficult for me to see the lights dim.

To recap, all the glow plugs have a resistance of 8.8 or 8.9. The harness seems to be alright considering I get a error code when I unplug any one of the glow plugs. By unplugging the CTS the ECU defaults to the fuel temp senor. When unplugging the FTS the ECU can read the CTS just fine, and both when plugged by itself are consistent with the other. When both are unplugged the ECU defaults to -4.5c. In either of these instances the glow plug light give .5 seconds. VCDS testing of the glow plug relay dims the cabin lights until the test has finished. I swapped out a different relay with no effect. The fuse is fine. No fault codes whatsoever. I did try to swap out the ECU with no effect but now I am wondering if it was alright. I did not do anything with the mobilizer so perhaps my test flawed. My gut says programming flaw, that for whatever reason the ECU programming is wrong, as demonstrated by its lack to default to -40 when the CTS is unplugged, and the fact that during output test it can turn on the GP relay but during regular use it cannot...tells me that it just does not want to even though the input factors such as coolant temp are functioning correctly.
freakwithracket is offline   Reply With Quote
Old October 15th, 2012, 11:22   #9
Growler
Got Soot Vendor
 
Growler's Avatar
 
Join Date: Nov 2003
Location: Millersport, Ohio
Default

Are you getting voltage at the glow plug harness connections when the coolant temp sensor is unplugged? you will need a helper to cycle the key for you while you check each plug port on the harness.

and VCDS to clear the codes that this will throw.
__________________
~Aaron~
Schnurren 2001 Golf 2 door. Knurren 2003 Jetta Wagon.
TDI Service Calendar link.Click Here.
Growler is offline   Reply With Quote
Old October 15th, 2012, 11:50   #10
firehawk618
Veteran Member
 
Join Date: Aug 2003
Location: Marysville, WA
Fuel Economy: unknown, will track on fuelly
Default

Funny how the OP says they want to just hook up a manual switch and isn't interested in any more troubleshooting but every post is troubleshooting.

All you have to do is run a wire to your GP relay and either power or groudn that wire.

I will look when I get home and advise you which wire to tap and what to send to it.
firehawk618 is offline   Reply With Quote
Old October 15th, 2012, 12:32   #11
csstevej
Veteran Member
Default

Are you saying each GP is reading 8.9-8.9 ohms of resistance? It should only read about .8-1.5 or there abouts of resistance. That may be some of your problem.
__________________
2001 golf auto to 5 speed manual swap,G60/VR6 clutch setup,coolant migration mod.
csstevej is offline   Reply With Quote
Old October 15th, 2012, 12:40   #12
Vince Waldon
Veteran Member
 
Vince Waldon's Avatar
 
Join Date: Apr 2009
Location: Edmonton Alberta Canada
Default

To run an LED on the dash that tells you when your glow plugs have power I tap into the glowplug harness in the cableway that runs behind the air filter.

Thin green wire in this picture:




Ignore the big red wires at the bottom of that picture... they are going to this:



Got tired of flaky harness connectors and am trying an experiment with spade lug connections.
__________________
Vince Waldon
Edmonton AB Canada
2001 silver TDI Jetta, Malone Stage 1.5
2001 blue TDI Jetta, Malone Stage 3. Grrrr baby... very grrrrrrr!
1970 Bay Window bus... not so grrrrr
Vince Waldon is online now   Reply With Quote
Old October 15th, 2012, 13:26   #13
JB05
Veteran Member
 
Join Date: Oct 2005
Location: Il.USA
Fuel Economy: 43/41/40
Default

I too have a pilot light for the GP's and was surprised to find that they run practically year round, although the duration varies. Another thing worth mentioning is I have a scan gauge and the coolant temperature is always a few or more degrees warmer at cold start up than the outside temperaure, sometimes 10 degree difference.
JB05 is offline   Reply With Quote
Old October 15th, 2012, 15:39   #14
dtvenus
Newbie
 
Join Date: Sep 2012
Location: Huddersfield, UK
TDI(s): Seat Leon
Default Wiring up heavy duty glow plug switch to replace relay

My issue was the glow plug relay switching on only when the engine started! No good for warm up and no good for the glow plugs. Fortunately I left the harness pulled off the new plugs I'd fitted and used Easy Start spray, until I decided to fit a manual switch after my nephew suggested this was an option.
Bought a heavy duty push switch which releases as soon as you let go ( good, because you don't want the plugs on after the engine starts). Along with 17 amp wire (should ideally be 35 I think, but the glow plug circuit is only switching on the 5 seconds needed to warm up the combustion chamber) and two 35 amp connectors. I'm in the UK and couldn't get the male blade connectors to slot in the 12 volt supply and exit to the plugs, where the relay plugs into the rail underneath the steering wheel ( My TDI is a Seat Leon). I bought flat round connectors designed for bolting to a threaded stem. I filed them at each side to get down to the same width as the heavy duty blades on the relay.
Drilled a hole for the switch in the plastic trim which completes the facia under the steering wheel. Jobs a gud'n as they say. The circuit is fused from the battery supply, so if the wiring I've put in managed to short out, it should blow the fuse. ( I tested all this would work by first pushing a connecting wire into the two slots where the relay fits, and taking a reading at the harness to plug connectors. I would advise to do the same first).

Last edited by dtvenus; October 15th, 2012 at 15:52.
dtvenus is offline   Reply With Quote
Old October 15th, 2012, 17:18   #15
Alchemist
Veteran Member
 
Join Date: Nov 2007
Location: Huntsville, Ontario
Default

This should be what you are looking for. The ECU sends 5V from pin 9 to the glow plug control module (aka relay) via a blue/black wire, which connects to pin 10 the ST terminal. The control module sends 12V to the plugs as long as it is getting 5V from the ECU. All you need too do is put 5V on this line and the plugs will be on. The easiest way to get the 5V is with a regulator such as 78L05. Radio Shack probably has them for a reasonable price. It is a very small device and uses a simple hookup, just 12V in, ground and 5V out.

Paul
__________________
04 Golf, Evo skidplate, South Bend SMF and Stage 3 clutch, ventectomy, 176K miles, RocketChip tune.
99 Ranger about to be TDI. 02 Jetta parts car
VCDS, Heated shop with hoist
Alchemist is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Glow plug flashing & brake light switch out-coincidence? lmquinn TDI 101 9 April 19th, 2007 21:13
Glow Plug Light Flashing - Not Brake Switch benmarks TDI 101 14 February 11th, 2007 11:17
Flashing Glow Plug; Brake light switch? VWScully VW MKIV-A4 TDIs (VE and PD) 4 October 2nd, 2004 18:34
Intermittent Brake Light Switch Flashing Glow Plug TDI John VW MKIV-A4 TDIs (VE and PD) 1 July 27th, 2004 13:31
Flashing Glow Plug light/Brake switch troubleshoot IowaStater VW MKIV-A4 TDIs (VE and PD) 2 July 27th, 2004 08:40


All times are GMT -7. The time now is 22:44.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2014
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
© 1996 - 2013, All Rights Reserved
Page generated in 0.15581 seconds with 10 queries
[Output: 132.48 Kb. compressed to 111.40 Kb. by saving 21.08 Kb. (15.91%)]