Flashing glow plug symbol

Grapeape · January 22nd, 2019, 16:34

Hey all. I hate being a bother but I hope you can help. It was -30 here and when I went to start my 05 jetta tdi the glow plug light was solid then started flashing it turned over very slowly then stopped. It wouldnt turn over anymore. I have the glow plugs I had the fault so I purchased 4 new ones. Also my battery didnt have the cold cranking amps I needed in our cold Ontario weather so I just purchased a new one and put it in. The glow plug light is still going solid then blinking and I believe this is stopping the car from turning over. Thoughts??

KLXD · January 22nd, 2019, 16:57

Never heard of a flashing plug light causing that. Sounds like a bad starter to me, maybe wiring.

Or a bad new battery. Happened to me once in sunny California. Installed it in the store's parking lot and nothing. Buggers wouldn't even hand me a new one. Had to do the warranty paperwork.

How about proof reading your prose?

Grapeape · January 22nd, 2019, 17:02

I dont think so. It just happened when it was so cold. It seems because of the glow plugs.

AndyBees · January 22nd, 2019, 17:28

I have no clue on the 05, but there is a long list of things that will cause the GP light to flash. I use to have the list. Seems MOGolf compiled that list. It may be in a sticky.

VW also used the "the flashing GP light" as an indicator something wasn't happy. Have you had it scanned with VCDS or something similar?

Grapeape · January 22nd, 2019, 17:32

Yes I have the scan software on my laptop and I had the check engine light came on a while ago and I should have changed them then. I bought new ones. As for the scan it came back as 1 and 4 glow plug fault. And I've never had the coil indicator flash until it hit these really cold temperatures.

AndyBees · January 22nd, 2019, 17:44

Grapeape, this may not be applicable to your 05 .. (it does apply to the ALH engine)

MOGolf .......... credit to him. (this is a copy and paste from one of my posts back in 2015)

Causes of flashing glow plug light

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

Grapeape · January 22nd, 2019, 17:51

I'll have to scan it again tomorrow in the light. I believe it was the 18027/1619

Fahrvegnugen · January 22nd, 2019, 18:00

I guess Battery, ground or electrical problem, is the glow plug harness good? Reading Andy’s list makes me think of a bad cable or ground connection, or wires shorting out.

Vince Waldon · January 22nd, 2019, 18:20

The flashing glowplug light means the ECU has detected a "fix me now!" problem NOT related to the glowplugs (dunno why VW chose to use the glowplug light).

Scanning with a good VW-specific scanner is the best next step.. .if there are a bunch of codes clear 'em and see what comes back.

Fahrvegnugen · January 22nd, 2019, 19:03

Oh that’s right Vince. I recall it getting cold and my glow plug lights would flash and ding and my headlights would turn off. I replaced my battery cables and it never did it again.

jokila · January 22nd, 2019, 19:52

Quote:

Originally Posted by Grapeape

I dont think so. It just happened when it was so cold. It seems because of the glow plugs.

Cranking of the engine is unrelated to the glow plugs. You have a power problem in starting the car. Check the wiring and grounds. Is this a manual car? Anything related to the starting system can be suspect. Did you check the voltage of the battery before deeming it a failure?

Grapeape · January 22nd, 2019, 19:55

Yes the battery was shot. And yes it's a standard.

Grapeape · January 24th, 2019, 14:48

Update. I just got a new odb scanner to work with my phone. The only stupid thing I did in a hurry to get it fired up was clear the codes before I saved them. I believe it said it was a 7036 or 7042 powertrain fault code. There was 4 of them. I cleared them but it still wont turn over. Any thoughts. The glow plug light is working normal now. I did replace all 4 of them.

jokila · January 24th, 2019, 15:17

Quote:

Originally Posted by Grapeape

Update. I just got a new odb scanner to work with my phone. The only stupid thing I did in a hurry to get it fired up was clear the codes before I saved them. I believe it said it was a 7036 or 7042 powertrain fault code. There was 4 of them. I cleared them but it still wont turn over. Any thoughts. The glow plug light is working normal now. I did replace all 4 of them.

The codes will come back if the engine is started, but if you are getting zero cranking then you have to look into the starting circuit, from ignition switch to lines that feed power - not necessarily in that order though. eg: clutch safety switch keeps the starter from engaging.

You might try bypassing the starting circuit by jumping the power to the starter. If that works, you would need to figure out the circuit and isolate where the failure point is located.

Grapeape · January 25th, 2019, 09:24

Any idea if there is a way to bypass the clutch safety switch or diagnose it.