glow plug lite blinking

jxb

Member
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Aug 13, 2017
Location
kennesaw ga
TDI
2006 tdi jetta
2006 vw jetta 208k miles outside air temp 43f tried to start the glow plug lite blinking, would not even try to start no other warning lites on, ckd brake lites ok, no previous problems even with colder weather.
 

STDOUBT

Veteran Member
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Jul 30, 2007
Location
Portland, effing Oregon
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dos jettas
You need to have it scanned for codes. There are numerous causes for that MIL, many of which have nothing to do with the glow plug system. OBD2 might point you in the right direction, but a scan with VCDS would nail it down.
 

vol4til3

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Aug 17, 2020
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Namibia
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golf 4
Must be the brake light switch fail, or you replaced a brake bulb that is not 21W or BOTH your brake bulbs are dead.
 

jxb

Member
Joined
Aug 13, 2017
Location
kennesaw ga
TDI
2006 tdi jetta
No code shown, checked glow plugs with ohm meter, all read about .9 to
1.0 ohms, also checked voltage from harness read 5.9 to 6.0. Lite comes on steady for a few seconds then starts to blink and at that time the voltage readings go to zero. Is there a timer and where is it. fuses have been checked brake lites work normal as do the turn signals.
 

Vince Waldon

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2001 ALH Jetta, 2005 BEW Wagon
As above, issue will have nothing to do with the glow plugs... flashing light just means the ECU has detected a "FIX ME NOW" issue. Brake circuit problem, injection pump problem, accelerator pedal, potentially glow plug relay itself... there's 20+ possibilities unfortunately.

You'll need to track down a VW-specific code reader... the code will be there, just not accessible with a generic OBD2 scanner.
 

Tdijarhead

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Nov 10, 2013
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2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
Here is a list of most of those 20 or so things Vince tells about.

The most probable cause would be related to your brakes


Flashing glow plug light

The flashing glow plug is sort of a super "check engine light". It flashes when the ECU detects that certain very important components are out of spec.

Per a post by MoGolf, the codes that cause a flashing glow plug light are below.
.

00741 Brake pedal monitoring - implausible signal
01044 Control unit incorrectly coded
16705/P0321 Engine speed sensor - implausible signal
16706/P0322 Engine speed sensor - no signal
16955/P0571 Brake light switch (F) - implausible signal
17653/P1245 Needle lift sender (G80) - short to earth
17654/P1246 Needle lift sender (G80) - Implausible signal
17655/P1247 Needle lift sender (G80) - Open circuit/short to positive
17762/P1354 Modulating piston movement sender (G149) - electrical fault in current circuit
17969/P1561 Metering adjuster (N146) - control difference
17978/P1570 Engine control unit blocked
18020/P1612 Control unit incorrectly coded
18026/P1618 Glow plug relay (J52) - short to positive
18027/P1619 Glow plug relay (J52) - open circuit/short to earth
18040/P1632 Accelerator position sender - voltage supply
 

jxb

Member
Joined
Aug 13, 2017
Location
kennesaw ga
TDI
2006 tdi jetta
As expected the glow plug harness fell apart,. and the glow plugs are the original, so I will change both, is there a vw code reader I can buy for a reasonable amount.
 

jxb

Member
Joined
Aug 13, 2017
Location
kennesaw ga
TDI
2006 tdi jetta
As above, issue will have nothing to do with the glow plugs... flashing light just means the ECU has detected a "FIX ME NOW" issue. Brake circuit problem, injection pump problem, accelerator pedal, potentially glow plug relay itself... there's 20+ possibilities unfortunately.

You'll need to track down a VW-specific code reader... the code will be there, just not accessible with a generic OBD2 scanner.
 

BobnOH

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May 29, 2004
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central Ohio
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New Beetle 2003 manual
Reasonable? The Ross Tech VCDS is the most cost effective full function scan tool for your car.
 

Tdijarhead

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2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
Most other manufacturers propriety scan tools run several thousand dollars often with a monthly subscription on top of the purchase price that will be 2 hundred or more per month. Ross-tech vcds is very reasonable.
 

Vince Waldon

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Apr 25, 2009
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2001 ALH Jetta, 2005 BEW Wagon
OP if the issue was the glow plugs themselves you would have a solid Check Engine light and a 380 code that your generic scanner would be able to see. :)
 

Nuje

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Island near Vancouver
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2015 Sportwagen; Golf GLS 2003; 2016 A3 e-tron
Most other manufacturers propriety scan tools run several thousand dollars often with a monthly subscription on top of the purchase price that will be 2 hundred or more per month. Ross-tech vcds is very reasonable.
Yep - you're not going to do much better than VCDS. If you're going to own a 10+yr. old car for any significant length of time, this will pay for itself in year one, almost for sure.
 

STDOUBT

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Location
Portland, effing Oregon
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dos jettas
As expected the glow plug harness fell apart,. and the glow plugs are the original, so I will change both, is there a vw code reader I can buy for a reasonable amount.
You said the glow plugs are all ohm'ing withing 0.1 of each other? and they are all about 0.9?
Don't change them, they're fine!
Plugs should all be between 0.5 and 1.5 ohms, and within 0.2 - 0.3 ohms of each other.
 

Tdijarhead

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Location
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2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
Here’s a guy on this forum selling a vcds. After you get rid of your car you can usually get at least half of the purchase price back by selling it. I have an older unlimited vin cable, I paid $249 or $299 I don’t recall. I could probably get close to $200 if I put it up for sale today. The residual value of a vcds is quite good.

 

wonneber

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2006 vw jetta 208k miles outside air temp 43f tried to start the glow plug lite blinking, would not even try to start no other warning lites on, ckd brake lites ok, no previous problems even with colder weather.
Please clarify "would not even try to start"
Did the starter work and the engine crank over?
Do you hear the fuel pump in the tank running for a few seconds?
Scanning for codes to diagnose it should be cheaper then throwing guessing at it parts.

As mentioned above, did you check if both brake lights are working?
I had that cause the GP light to blink.
 

AndyBees

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May 27, 2003
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Southeast Kentucky
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Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
Hoards of excellent advice for the OP and a list of possibilities as to why the GP light is flashing as well as a good reference on an OBD port code reader.... Heed the advice! And, I agree 100%, the GPs are fine. The broken up GP harness is fine too! The harness on my 03 is OE and has the broken plastic with pieces missing ! It's function is fine! .... but, I do understand peace of mind!
 

jxb

Member
Joined
Aug 13, 2017
Location
kennesaw ga
TDI
2006 tdi jetta
Please clarify "would not even try to start"
Did the starter work and the engine crank over?
Do you hear the fuel pump in the tank running for a few seconds?
Scanning for codes to diagnose it should be cheaper then throwing guessing at it parts.

As mentioned above, did you check if both brake lights are working?
I had that cause the GP light to blink.
Engine turned over normally, tail lites are working normally, heard fuel pump work,
 

AndyBees

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May 27, 2003
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Southeast Kentucky
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Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
To be clear, it is not "tail lights" ........... it is the Brake Lights. The left and right brake lights are monitored by the ECU and the upper in the window light is not monitored by the ECU.
 

Tdijarhead

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Nov 10, 2013
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Lawrenceville PA
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2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
^^^^ Have your wife or a helper step on the brake pedal while you watch for brake lights. No brake lights equal flashing glow plug light.
 

BobnOH

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May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
I had posted earlier that it may have been brake lights. But that ain't right, would not cause no start.
Assume all was well before this condition.
A good code scan is going to help. But you also can check things over for loose plugins or piping, blown fuses, crispy wires, etc.
 

wonneber

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Oct 12, 2011
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Monroe, NY, USA
TDI
2014 Jetta Sportwagen, 2014 Tiguan,2003 Jetta 261K Sold but not forgotten
is there a vw code reader I can buy for a reasonable amount.
VCDS Lite is free to use but has a few functions not enabled.
For reading codes it will work.

Do you have a laptop and an OBD cable to use?
The hard part is finding a cable that will work correctly.
The USB cables may not work.

Maybe someone here can post which one they bought that works.

Check: Ross-Tech: VCDS-Lite: Download (ross-tech.com)
 

noob_tl

Well-known member
Joined
Mar 30, 2012
Location
Central Indiana
TDI
2003 NB
I can't find the ebay receipt, but this one looks exactly like mine, and it works well with VCDS-Lite.
 
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