2002 No Glow plug light

[TB]

I had my 02 tdi off the road for a year and a half but started it up regularly and let it run. I put it outside and let it sit for two weeks and now the glow plug light does not come on. The injector pump solenoid is not getting power either but when I jumper the injection pump solenoid to 12 volts, the glow plug light comes on and it starts and runs just fine.
Should I find the glow plug fuse first? Relay 109 is fine, I had a spare..
Thanks 450 k

 

[Mozambiquer]

You've got no power from the relay 109. Check for the ecm fuses.

 

[TB]

Thanks for the reply. Will do! I'm not sure why anything would change but she's an old girl...

 

[TB]

You've got no power from the relay 109. Check for the ecm fuses.

I found two bad fuses and replaced them. Relay 109 still isn't kicking in. With the cover off the relay I can manually close the relay and the glow plugs and the injector solenoid work but it won't react when I turn over the key... Any more thoughts?

 

[Vince Waldon]

Best bet would be to track down the schematic and follow the electrons from the battery to Relay 109... they are going missing somewhere along the way.

That said, a worn ignition switch is common on older TDIs and can cause these symptoms. There's a set of contacts that provide power with the key "on" but interrupt power when the key is turned to "start" but also a set that provide power in both the "on" and "start" position... which is the case for Relay 109. The majority of loads are on the first set of contacts (so that these loads are off when attempting to start the engine) so you don't always notice the second set getting dodgy.

Lots of threads here with good pictures detailing how the switch section of the ignition tumblers gets replaced.

Following the electrons methodically is still the best (and cheapest in the long term) approach.

 

[TB]

Best bet would be to track down the schematic and follow the electrons from the battery to Relay 109... they are going missing somewhere along the way.

That said, a worn ignition switch is common on older TDIs and can cause these symptoms. There's a set of contacts that provide power with the key "on" but interrupt power when the key is turned to "start" but also a set that provide power in both the "on" and "start" position... which is the case for Relay 109. The majority of loads are on the first set of contacts (so that these loads are off when attempting to start the engine) so you don't always notice the second set getting dodgy.

Lots of threads here with good pictures detailing how the switch section of the ignition tumblers gets replaced.

Following the electrons methodically is still the best (and cheapest in the long term) approach.

Thanks Vince. I just found my old Haynes manual! I'll keep on keeping on I agree, gotta be something between the ignition and relay 109. Keep ya posted..

 

[csstevej]

Just for $hits and grins……what color is the 109 relay you have now?
If it’s the black one they are prone to failure…..the newer ones are gray.

 

[TB]

Just for $hits and grins……what color is the 109 relay you have now?
If it’s the black one they are prone to failure…..the newer ones are gray.

It is a gray one. I had replaced it some five years ago. I bought a new one and it didn't make a difference. Somewhere, the power isn't getting to that relay.

 

[csstevej]

Ahh ok….
Critter damage by the ECU?

 

[TB]

From the schemati

Ahh ok….
Critter damage by the ECU?

Don't say that LOL. I'll check that for sure. It was sitting for quite a while.

 

[csstevej]

Lol…..hopefully if that the case it will be right at the ECU……thats where I had a nest on a NB I bought for one of my daughters……. Luckily no chewed wires……