Where is the Glow plug relay on a 2003 Not under the windshield

Hello all,
I am trying to replace the glow plug relay to get rid of the annoying light/ engine code. I have read that for the 2003 jetta the relay is under the plastic shield under the windshield. I removed it and can not find the relay... everyone say it is in your face but I simply cannot locate it. I opened up the plastic cover with the wires going into it on the driver side and I can't seem to find it under there... Is there anyplace else that they put these darned things for this year?

I don't know how to post pics but I have taken some if that helps and someone can help me get them on here... also I am in southern vt (brattleboro) if anyone lives close by and could give me a hand. Thank you.

The GP relay is not on the Relay Panel as per the Bentley Manual. In your case, I'm thinking it may be up in the area above the accelerator pedal. It is a rather large relay compared to those in the panel. It is secured by a screw and has among other smaller wires, two large red wires going to it.

I've read comments/discussions/debates as to whether or not that relay is malfunction prone.

Have you "priced" a new one!

There is a long list of reasons for the GP light to be on. I'm not sure if any of these will also cause the CEL to be on at the same time. ......... I hope this helps.

Here is the list:

Copied this from a post here in the club.

MOGolf I think did the most of it, I can't remember who else to credit.

Causes of flashing glow plug light

Because this is a frequently asked question, I (MOGolf) went digging through info for '01 ALH and made the following list of known reasons for the glow plug light to flash. They are listed with the VW code and generic reader P code.

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
17970 - Quantity Adjuster (N146): Upper Limit Reached
P1562 - 35-10 - - - Intermittent

It also flashes when an interface tool has put the ECM in 'basic settings' mode.

There may be more; these are the ones I found documented.

The brake light monitoring includes the clutch switch (manual transmission cars). It also includes a possibility of blown brake light bulbs.

I also had a NB that had a blown bulb on one side(glow-plug light flashing), replaced it & customer left, came back& other side the dual filament had broken & fused across the taillight filament inside the bulb. Replaced the bulb, good to go.

I am not sure when they moved it, but I think yours is in the same place as mine. I seem to remember that any 4 wire glow plug harness car (as opposed to the two wire system) will be there.

It is in the windshield plenum.
It is NOT in your face. I have had a half dozen open and never noticed it.
It is tucked under a large wire run from the ECU, on the car left side of the ECU, on the front lip of the plenum.
I never noticed it until I was pulling a 2005 wreck apart.



It is not large at all. Easy to miss.

I am pretty sure that it is the relay... I had the code scanned at an auto parts store and it showed an error code for all the plugs... replaced all plugs and harness and still the same code... I have already bought the relay and just want to install it... I appreciate the descriptions but if anyone had a picture that would be the most useful to me as I am a visual learner. I will however go outside and try to find it again... Thank you all for such quick replies and all the help...

Andy and Dan got you going on the right path. The relay is not failure-prone so look at the rest of the system.


Here is where a GP relay resided - this is all that was left after an arc flash at the GP relay. Some hail knocked holes in the rain tray allowing rain to get into the connections of the GP relay, increasing resistence until the flash happened. Lesson learned to all - replace a broken $70 rain tray to prevent further damage to your $300 GP relay and $600 engine wiring harness.

also this is the relay I bought... the guys at idparts swear its the correct one http://www.idparts.com/catalog/product_info.php?products_id=389

Thank you greengeeker... I have that picture was worth a thousand and within 30 seconds I found it... It is now replaced... along with all other components of the glow plug system and still that damn light went on.... how do I go about checking through the checklist that Andy provided? The light doesen't flash it it just goes on and stays on... I don't have a vagcom but the code reader at the auto parts store says it is the glow plugs? What gives? I am so frustrated with this thing!

If your glow plug light goes on and stays on it is not the glow plugs but possibly your brake light switch on the brake pedal.

Step 1: Find someone local-ish with vcds (vagcom) to scan your car for stored codes. DO NOT THROW ANY MORE PARTS AT YOUR CAR UNTIL YOU COMPLETE THIS STEP.
Step 2 will be determined by step 1.