Help: 3x breakdowns due to fuel system. Jetta 2008 2.0L manual

[Aralox]

Hi all,

I have a 2008 VW Jetta (manual) with around 90,000 kms on it. I live on the north shore in sydney.

It has broken down 3 times over the last few months as follows:

- Around 5 weeks ago, it would not start in a car park. Cranks fine. Fuel pump did not turn on when car turned on (no sound). NRMA checked battery, tapped tank, gave it gas and cranked, nothing. Towed it to mechanic the next morning. Mechanic changed the fuel pump, ~$750.

- Drove fine for 2 weeks, drove up to Forster for the weekend (around 5h north of Sydney where I live). Parked the car for a few hours. Started it again fine, while going around the roundabout, I felt the power give out, felt a bit like a stall, so I cruised over to the side. Car didn't start after that, same symptoms. NRMA found no spark, no power to the fuel pump. Called mobile auto electrician, he found that there was no signal from the ECU to the fuel pump relay under the steering wheel. Got it towed to a mechanic on monday. They couldn't find any relevant codes, so I had to leave the car up there for 3 weeks while they got people in to diagnose the problem. They narrowed down the problem (by verifying the circuits according to the wiring diagrams) to the fuel pump control module. They replaced it, ~$850.

- I drove it back to sydney, and drove fine to work the next week. On Friday (22/3/19), the car wouldn't start in a shopping mall car park. Fuel pump didn't turn on (no sound). NRMA tried to start it, but it was all the same symptoms. Tried fiddling with the wiring on the fuel pump & module, no luck. Code reader showed P025C fuel pump control module low (can't remember exact code, I remembered description and googled for the code). Booked a tow the next morning.

- This morning, NRMA came by again to help me get the car out of the shopping mall so it could be towed. The NRMA mechanic tried to start it too, after explaining the situation to him, he tried applying power to the fuel pump manually using a battery then trying to start, but didnt work. He then tried removing and cooling down the R1 (big square box) relay at the front, and starting again. It started briefly! But died again, and we couldn't reproduce the situation. The relay felt really hot. We couldn't figure out what relay it was, not mentioned in the owner's manual.

By the way they checked connectivity on all the fuses on the right side of the steering wheel, and in the front. I've never had any problems with my key or central locking. The only other codes that keep showing up is related to the windscreen wiper (888 and driver side door window motor (932).

I will call the mechanics that last worked on my car on monday, and try to sort out a service under warranty.
Does anyone have a full diagram of what all the relays are and where they are in the car? Has anyone experienced this?

I'd really appreciate any advice. Please ask if you would like any more detail.

Thank you,
Pravin

[Hillbilly]

Hi all,

I have a 2008 VW Jetta (manual) with around 90,000 kms on it. I live on the north shore in sydney.

It has broken down 3 times over the last few months as follows:

- Around 5 weeks ago, it would not start in a car park. Cranks fine. Fuel pump did not turn on when car turned on (no sound). NRMA checked battery, tapped tank, gave it gas and cranked, nothing. Towed it to mechanic the next morning. Mechanic changed the fuel pump, ~$750.

- Drove fine for 2 weeks, drove up to Forster for the weekend (around 5h north of Sydney where I live). Parked the car for a few hours. Started it again fine, while going around the roundabout, I felt the power give out, felt a bit like a stall, so I cruised over to the side. Car didn't start after that, same symptoms. NRMA found no spark, no power to the fuel pump. Called mobile auto electrician, he found that there was no signal from the ECU to the fuel pump relay under the steering wheel. Got it towed to a mechanic on monday. They couldn't find any relevant codes, so I had to leave the car up there for 3 weeks while they got people in to diagnose the problem. They narrowed down the problem (by verifying the circuits according to the wiring diagrams) to the fuel pump control module. They replaced it, ~$850.

- I drove it back to sydney, and drove fine to work the next week. On Friday (22/3/19), the car wouldn't start in a shopping mall car park. Fuel pump didn't turn on (no sound). NRMA tried to start it, but it was all the same symptoms. Tried fiddling with the wiring on the fuel pump & module, no luck. Code reader showed P025C fuel pump control module low (can't remember exact code, I remembered description and googled for the code). Booked a tow the next morning.

- This morning, NRMA came by again to help me get the car out of the shopping mall so it could be towed. The NRMA mechanic tried to start it too, after explaining the situation to him, he tried applying power to the fuel pump manually using a battery then trying to start, but didnt work. He then tried removing and cooling down the R1 (big square box) relay at the front, and starting again. It started briefly! But died again, and we couldn't reproduce the situation. The relay felt really hot. We couldn't figure out what relay it was, not mentioned in the owner's manual.

By the way they checked connectivity on all the fuses on the right side of the steering wheel, and in the front. I've never had any problems with my key or central locking. The only other codes that keep showing up is related to the windscreen wiper (888 and driver side door window motor (932).

I will call the mechanics that last worked on my car on monday, and try to sort out a service under warranty.
Does anyone have a full diagram of what all the relays are and where they are in the car? Has anyone experienced this?

I'd really appreciate any advice. Please ask if you would like any more detail.

Thank you,
Pravin

Why dont you take it to a proper VW workshop instead of people without correct diagnostic gear for the model

[Aralox]

Yes that's definitely the plan from this point onwards, now that the car is in sydney.

[JustCruisn]

Without the correct scan tools any repair is just a guess. For what you have paid so far you could have had it towed back to Sydney for much less.
I'll put a fiver on it being the cam position (hall) sensor.

[Aralox]

Haha, I'll keep that in mind, I actually have been told that some of the sensors on this jetta can be problematic. And I should have mentioned, the place in forster is an auto electrician - 'great lakes auto', they did actually have the VW scan tools. They didn't scan any relevant codes after the breakdown in forster though, only the ones mentioned in my post. To be honest I'm at the point where I might just go ahead and replace the cam position sensor blindly if you reckon that's got anything to do with this.

[saabman]

THat scenario sucks big time.

I personally hate the idea of blindly replacing parts with out KNOWING that the part is faulty. if your stuck on the side of the road and its an all Ive got to try thats one thing but been in a workshop it makes my blood boil when they do it. end of rant.

Getting a good scan and logging everything that is going on when the car tries to start is a good place to start. Whats the battery voltage, cam angle sensor should be able to be logged as well. Whats the fuel pressure?

Fuel pump failing to activate could be bad wiring in the drivers door harness or a bad door lock module. Intermittant problems are an absolute cow to chase down.
damaged wiring between fuel controler and ecu. the list of posibilities is endless.

It beats me why CAM and CRank postion sensors dont throw a fault code - SAAB' sdo the same thing - youd think they could tell starter motor running and no signal from the position sensor with in 5 seconds - throw a code but they dont.

Yes sensor are prone to fail

The relay getting hot is not a good sign - maybe post a pic of the fuse box indicating the particular relay - a relay getting hot could be a bad connection in the socket as well - one pin may show signs of excessive heating.

[saabman]

For service information have a look here

Volkswagen Workshop Manuals

Is it a diesel or petrol engine?

[brad]

There's a good independant on the North Side. Someone here will chime in with his name...

[Aralox]

Thanks saabman. I'm sorting out a VCDS scan using a friends help soonish, so I'll hopefully have more concrete info on codes etc. It's a petrol engine. Here are some pictures showing the relay

[saabman]

I had a quick look last night in Elsa win and that really appears to drive lots of stuff related to and probably the ecu as well. I didn’t notice fuel pump though but it does the fuel pressure regulator.
You mentioned that relay got hot, heat in a electric it hit indicates high resistance - either by design like a heater element or bad connection.
Either way where you have heat you have lots of powerloss.
Which the car running ( does it run at the moment) check the voltage between any of the following fuses and ground. The fuses have a little hole above the contacts you can stick a meter probe in , either hole will be fine.
Fusss 14, 23, 22, 13, 15, 24, 21. It should be up around 14v with engine running. Then while measuring the voltage give the relay a bit of tap and see if you notice any fluctuation in the voltage reading.

I suspect a VCDS scan will show some low voltage readings in conjunction with the heat from that relay which would point to that relay haveing bad contacts (worn/coroded) .

If you can get a full VCDS scan for faults also get a scan of all the sensors as well. It’s too early in the morning I can’t remember the right name of the scan.