2001 Jetta became possessed, 17957, 17849, 19561, 17552 and 17660

[ninedee_golf_tdi]

A perfectly fine running 2001 sat for a week or so, when I started it today those codes appeared and they are all legit. Timing off the chart, maf actual is 255, iq is now about 14, black smokes at idle and pump seems to be rattling. Yes, I checked the fuses and grounds. The codes are unclearable. No signs of mice damage. So I wonder.... what is the common denominator ? Thanks for your thoughts.

 

[ToxicDoc]

It all started suddenly and 4/5 are short to ground codes with a 5th being possible wiring problem. I'd say check your harness more carefully, especially where it goes through the firewall.

 

[ninedee_golf_tdi]

I inspected every inch of the harness, nothing chewed / chafed, not even a mouse turd. For giggles, swapped the ecu, no change. Switched to basic setting for component tests, no response from the n75, n18, n108 but there was available vacuum at each. If I put a component into its test sequence, I should see 12+ and a ground, correct. Just making sure I'm not losing my mind here. Final question, none of the magic involves the relay panel correct ? It all happens inside the ecu ? Just wondering if a relay died opening or closing a circuit to cause the errors.

 

[BobnOH]

This happens sometimes just from low battery current. See if a nice long trickle charge doesn't clear things up.

 

[ninedee_golf_tdi]

Odd that response.... I had taken the battery out of that car to put into another, and has since been swapped back. VCDS says voltage was around 13.98 when running a few minutes ago. It's a good guess and I have a new battery to put in it.... I hope the gremlin set up house in the old battery and get excised when the battery is swapped.

 

[ninedee_golf_tdi]

Sadly, the gremlin remains after a brand new, fully charged battery was installed. Maf actual remains at 550, can't command the n75 to test the activator, no egr test, timing off the chart, this is weird.

 

[BobnOH]

Just a guess based on reading these forums (too much). Battery voltage is not definitive when it comes to battery condition.
I think I'm reading the car was fine 2 weeks ago, now 5 codes. One of the Big wires??

 

[ninedee_golf_tdi]

The car was fine a few weeks ago.... it was blocked in by my forklift that refused to start, but that's another story. I've checked the grounds I know of with an ohm meter for corrosion, nothing, but cleaned them anyway. I'm not sure if it is one component that died, like maybe the n108 valve and took that circuit out, or ? I disconnected each of the solenoids for each code, no difference except when I disconnect the pump, I get two pump related codes (17971 n146 qa and 17762 g149) and the others go away except for the 17957 n75 code. Plug the pump back in, the two pump codes disappear and I get the same 5 original codes back.

 

[ninedee_golf_tdi]

Resolution. KISS, keep it simple stoopid. I did check all the fuses and all were and are still good. After confirming all the involved solenoids pin 1's and the maf pin 2 were connected via e29 but none were receiving key on 12v+, an eye watering trek through the schematic showed power was provided by fuse S234. That fuse was indeed good but it had a bit of corrosion on one leg and had to be tweaked in the fuse box a bit to get it to connect all the time. A new fuse instantly brought the possessed jetta back to its former glory. I remember closing the door a bit harder because of a freak rain storm, and that might have been what caused the fuse to get wonky. You just never know.

 

[BobnOH]

Confirms my theory that at least half the engine controls issues we see on these 20 year old cars are wiring/connects.
Nice work!

 

[wonneber]

Glad it working again.
I've always felt the ' short to ground codes ' are no power to the device.
A short to ground should pop a fuse.
I've always checked if there was power on both sides of the fuse.
I also read that some cheap fuses can crack internally.
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