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17945 Fuel Shut Off Solenoid code?

I keep receiving the following code, 17945 Fuel Shut Off Solenoid.
The Car goes into Limp mode.
I clear the code and it comes back a few days or engine starts later.
I replaced the fuel cut off valve and “O” ring but I still get the code. Sometimes 600miles, sometimes 20miles.
Never goes into Limp mode after a good engine start. Seems to throw the code on random start ups.
Have good 12 volts to the solenoid connection.

Any ideas?

2001 Jetta TDI

Thanks
 

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The fuel cut off valve on the injection pump? It should either be 12v with the ignition to "ON" or none when off. It's possible that the solenoid is bad but I am guessing a broken wire is causing the fault. Trace the wire along the harness and see if it's rubbing anywhere. These are the only two tests given in the service manual.

The solenoid is also called the n109 solenoid, BTW.

Some people report a bad o-ring which slips and either interferes with the functiom of the solenoid or lets in air, which would feel similar to limp mode. A few tiny air bubbles is acceptable, a bubble that is half the diameter of the fuel line is not.
 

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That is definitely a possibility, what other symptoms?

It's probably not the n109 fuel cut off solenoid since you already replaced it.

The o-ring could be causing fueling issue and causing limp mode but 2nd a wiring fault. Maybe corrosion on the wiring harness connector?

As a last resort, you could try switching the ECU and seeing if that changes anything. I've heard that mk4 TDI ecus sometimes do go bad. You didn't say which year it was for, you may need to reset the immobilizer if you try to swap the ECU. If you can't do that, don't try to swap it because then you are locked out and need a tow to the dealer. This would be a last resort so try some other things first.
 

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17945 Fuel Shut Off Solenoid code?

I keep receiving the following code, 17945 Fuel Shut Off Solenoid.
The Car goes into Limp mode.
I clear the code and it comes back a few days or engine starts later.
I replaced the fuel cut off valve and “Oâ€￾ ring but I still get the code. Sometimes 600miles, sometimes 20miles.
Never goes into Limp mode after a good engine start. Seems to throw the code on random start ups.
Have good 12 volts to the solenoid connection.

Any ideas?

2001 Jetta TDI

Thanks
This is a tough one, you fixed or checked all the obvious stuff. My guess is a wiring fault or other issue that is causing it and for whatever reason, this code is coming up. Do you have a stock EGR valve and anti-shudder valve? Did you change the adaptation value? Although it shouldn't give that code, when people on a stock car mess with the EGR, it can throw a code. Maybe for whatever reason, it's somehow setting another code related to engine shutdown.

The ecu could be bad. Coolant migration?
 

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If it were coolant migration he could check quickly by removing the coolant level sensor plug. Some other symptoms might be seen too. Again, it's possible it's a bad ecu. Don't know why they fail.
 

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Discussion Starter #6
This is a tough one, you fixed or checked all the obvious stuff. My guess is a wiring fault or other issue that is causing it and for whatever reason, this code is coming up. Do you have a stock EGR valve and anti-shudder valve? Did you change the adaptation value? Although it shouldn't give that code, when people on a stock car mess with the EGR, it can throw a code. Maybe for whatever reason, it's somehow setting another code related to engine shutdown.

The ecu could be bad. Coolant migration?
Yes I have a stock clean EGR valve and anti-shudder valve. And yes I did change the adaptation value per recomendations to 33768 prior to this trouble. everything elese is stock. Could they be linked? If so I will try changing back to stock EGR adaption and see what happens. You raised an interesting question...
 

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Discussion Starter #7
If it were coolant migration he could check quickly by removing the coolant level sensor plug. Some other symptoms might be seen too. Again, it's possible it's a bad ecu. Don't know why they fail.
checked for coolant migration in the connector and wireing... none, nice and clean. thanks
 

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It's not the injection pump, I see no reason why it would cause it and you already replace the solenoid and oring. I don't think it's the ECM but it's possible. Is it getting more frequent or no change? Have you checked the wiring all the way from the solenoid to the ECM? You can try asking on TDIclub or VWvortex and see what they say as well.
 

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Discussion Starter #13
It's not the injection pump, I see no reason why it would cause it and you already replace the solenoid and oring. I don't think it's the ECM but it's possible. Is it getting more frequent or no change? Have you checked the wiring all the way from the solenoid to the ECM? You can try asking on TDIclub or VWvortex and see what they say as well.
No it's not getting more frequent.. every 3 or 4 days of on and off driving. This is getting frustrating carrying around my laptop and Vag-Com to reset it. :eek:
 
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No it's not getting more frequent.. every 3 or 4 days of on and off driving. This is getting frustrating carrying around my laptop and Vag-Com to reset it. :eek:
You need vag com to reset it? I thought you could reset limp mode just by turning the car on and off. Maybe there is something more serious?
 

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Discussion Starter #15
Yes I need to reset the code for it to come out of limp mode.
Restarting the car will not clear the code or get it out of limp mode.
 

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:dunnoUpdate: 17945 Fuel Shut Off Solenoid code?

2001 Jetta TDI 130,000 miles.

At random start ups I receiving the following code, 17945 Fuel Shut Off Solenoid, and the Car goes into Limp mode, No CEL light. I can tell it has thrown the code because the engine will rev to about 2000 RPM momentarily at the start up.

I clear the code and it comes back a few days or engine starts later.
I replaced the fuel cut off valve and O ring but I still get the code. Sometimes 600miles, sometimes 20miles.
Never goes into Limp mode while driving, only when the 17945 code is thrown at random starts. Never trips the Check Engine Light. Have good 12 volts to the solenoid connection. Voltage good to solenoid, engine off 12.5 volts, running 13.8. Voltages solid with a good wiring and connector shakedown. Cleaned ECU terminals, they were clean and under the hood looks like a new car no corrosion anywhere.
Have a stock clean EGR valve and anti-shudder valve, and clean intake. I did change the adaptation value per recommendations to 33768 prior to this trouble, everything else is stock. I did change it back to stock and still have the problem.

Went 4 days and at least 15 starts this time before 17945 thrown again.
Decided to try disconnecting the battery and shorting the battery leads together to reset the computer as a shot in the dark try at this point. Cleaned battery terminals at both ends and added an extra 4awg ground straight to the starter. No luck code thrown and limp mode the next day.
I really doubt it's the ECU but I'm sure that's what the dealer would try to sell me!
Any ideas?
Please any help would be great!

Thanks

New info:
Found my Idle Injection Quantity read 18mg/r so being I could not adjust it down that far by Vag-Com I used the Hammer Mod to bring it down to 4. Now throws the 17945 code every start and revs high and smokes at start.
So changed it to 11. Mg/r and same thing. So changed it to 18.6 and is hard starting “5 seconds cranking” but no 17945 code yet and no smoke. Will drive it like that for a while and see if the code is thrown again.

Any ideas?
 

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I think something is wrong with your pump or ECU. My GUESS is that it should not be throwing these codes simply by moving the quantity adjuster. At this point you could try swapping the ECU with a known used good one since it's the cheapest and easiest solution. I normally wouldn't suggest buying parts without confirming the problem but you can't confirm the problem without swapping the ECU with a good one.

It's not an engine problem, it's not a wiring short or corrosion on the plug since you checked for broken wires, cleaned the grounds and the ECU pins, etc.. That narrows it down to ECU, injection pump, or bad solenoid.
 

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Discussion Starter #18
I think something is wrong with your pump or ECU. My GUESS is that it should not be throwing these codes simply by moving the quantity adjuster. At this point you could try swapping the ECU with a known used good one since it's the cheapest and easiest solution. I normally wouldn't suggest buying parts without confirming the problem but you can't confirm the problem without swapping the ECU with a good one.

It's not an engine problem, it's not a wiring short or corrosion on the plug since you checked for broken wires, cleaned the grounds and the ECU pins, etc.. That narrows it down to ECU, injection pump, or bad solenoid.
I'm starting to think it's something in the injection pump, but because I don't understand the inerworkings I'm at a loss...
 
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