Need help with 1998 Jetta CEL light

lbarrack

New member
Joined
Nov 12, 2007
Location
Chula Vista, CA
TDI
1998 Jetta
First - I have been through this forum and found it very helpful.
Some history - I bought this car a few weeks ago for 3500.00. It had 193000 miles on it but seemed in good shape - small dealer, saw it would need tires and stereo but little else.

After driving it a few days, noticed the airbag light would flash on and off (seems to be related to bumps in the road). Had a stereo and amp put in. A few days later the CEL light came on. I got my mechanic (who does not specialize in VW's) to read the code. It was realated to vacuum hose (P0605). I checked your forum and found the procedure to replace the hose in the ECM and had my mechanic tear it appart. He checked the vacuum hose with on it and it was measuring no vacuum loss on his tool. He then suggested to take it to the dealer.

The dealer found other hoses that were bad, replaced them and cleared the codes. About 40 min later the CEL light came on again. I took it back to the dealer and this time they said it's throwing out a 65535 code and I would need to replace the ECM. But they also said that it appeared as if I was running normally, there were no vacuum lline problems and that I could just ignore it.

Now, however, my airbag light is coming on more frequently. Are they related? I saw something here about the airbag relay getting corrupted but it looks like it applies to later models.

Any help would be appreciated. By the way, the car drives fine, no loss of power or gas mileage (about 38 all around).
 
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rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
lbarrack said:
First - I have been through this forum and found it very helpful.
Some history - I bought this car a few weeks ago for 3500.00. It had 193000 miles on it but seemed in good shape - small dealer, saw it would need tires and stereo but little else.

After driving it a few days, noticed the airbag light would flash on and off (seems to be related to bumps in the road). Had a stereo and amp put in. A few days later the CEL light came on. I got my mechanic (who does not specialize in VW's) to read the code. It was realated to vacuum hose (P0605). I checked your forum and found the procedure to replace the hose in the ECM and had my mechanic tear it appart. He checked the vacuum hose with on it and it was measuring no vacuum loss on his tool. He then suggested to take it to the dealer.
Well, this hose measures pressure - not vacuum. If he was in there, he should have swapped out that hose - they deteriorate and the time spent to get there is about 100X the cost of replacing it once there. His test told you nothing.

lbarrack said:
The dealer found other hoses that were bad, replaced them and cleared the codes. About 40 min later the CEL light came on again. I took it back to the dealer and this time they said it's throwing out a 65535 code and I would need to replace the ECM. But they also said that it appeared as if I was running normally, there were no vacuum lline problems and that I could just ignore it.
That little hose in the ecu causes this type of problem. Swap it out.

lbarrack said:
Now, however, my airbag light is coming on more frequently. Are they related? I saw something here about the airbag relay getting corrupted but it looks like it applies to later models.

Any help would be appreciated. By the way, the car drives fine, no loss of power or gas mileage (about 38 all around).
Airbag lights mean one of two things - the airbag is getting bad, or the connections are bad.

Only 38 mpg? Odd - do you drive almost exclusively city?
 

lbarrack

New member
Joined
Nov 12, 2007
Location
Chula Vista, CA
TDI
1998 Jetta
Thanks for the fast replies. I'll try to answer your questions to the best of my knowledge.

On the line inside the ecm, he hooked up a gadget to one end and it pumped pressure into it and did not loose any pressure. That is why he did not replace it.

They cleared out all the codes when they reset the ecm. When the cel light came on again it only threw out the 65535 error this time. They said it was a checksum error but could not find anything wrong. Do you think that this is now an airbag related problem? The light was not coming on for that when they had it.

As for the gas mileage - it is disapointing but I do hit a lot of stop and go traffic when I drive. I have had the car for only 3 or 4 weeks and perhaps as my handling of a stick improves, so will my driving.
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
Last I have to say on this subject.

push here

Replace the hose, and the one that goes to the innercooler from the ecu.
 

jettagirl98

Member
Joined
Nov 2, 2007
Location
Victoria, BC
TDI
98 Jetta TDI
Well, I am definitely not the expert here but sounds to me like you may have two completely unrelated problems here - vacuum hose and airbag issues. I also just recently bought a Jetta TDI, and have the P0605 code. Like a true newbie, I bought a new ECM off of Ebay - didn't help. So, then looked at this forum and looked at the vacuum hose inside the ECM - this hose was badly deteriorated on both the original and the one I bought! Unfortunately, this still hasn't fixed the problem...Next I'm going to try to replace some of the other vacuum hoses. I think your bad mileage could be due to this error though - if the car is in limp mode, my understanding is your mileage can go way down. My car also is only getting ~30 mpg. Good luck with yours, let me know when you fix it!
 
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jettagirl98

Member
Joined
Nov 2, 2007
Location
Victoria, BC
TDI
98 Jetta TDI
Just wanted to update everyone, since I finally fixed my P0605 CEL. The problem was (1) bad hoses in original ECM and Ebay ECM; and (2) bad original ECM. Now that the Ebay ECM is put in with a new hose, it seems to have fixed the problem. I've driven it 5 or 6 times with no CEL so far.

One question - I just had my timing belt replaced, and now I've put the new ECM in the car. Will this screw up the timing?
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
Contragulations. Glad it's fixed.

Hope it's fixed for the long haul.

No, new ecm should not impact timing.
 

jettagirl98

Member
Joined
Nov 2, 2007
Location
Victoria, BC
TDI
98 Jetta TDI
Nope, not fixed for the long haul. Sigh. All the vacuum hoses but one are done, and I'm not sure I have the confidence to try that one myself. Am trying a new N75 valve. Incidentally the CEL now displays two error codes: P0605 and P1550[SIZE=-1] "charge pressure deviation"[/SIZE]. I am hoping both these error codes are related to the same problem.
 

jettagirl98

Member
Joined
Nov 2, 2007
Location
Victoria, BC
TDI
98 Jetta TDI
OK, so I've replaced all the vacuum hoses (unless there are some hiding where you can't see them?). I've also replaced the N75 valve. No luck. From other posts on this forum I'm guessing it's time to look at my wastegate acutator. How tough of a job is this? Keep in mind I am a complete novice (I will not admit publicly how long a couple of those vacuum hoses took me) but I am also extremely tenacious. So...I'd rather not spend the money on a mechanic...how bad can I screw it up??
Thanks!
 

paramedick

TDIClub Enthusiast, Vendor
Joined
Jul 29, 2001
Location
Versailles, Kentucky
TDI
2015 Audi Q5 TDI, 2000 New Beetle
Not hard to do. Only thing is to have a bicycle pump and an adapter that will connect to the pump and the vacuum tubing. Many hardware stores sell an adapter that will work with the pump.

Disconnect the line to the wastegate actuator. Connect the bicycle pump to a short piece of vacuum tubing. Connect that to the actuator.

Have someone pump away while you look at/touch the rod on the actuator. It should start moving at <10psi pressure. If it moves, lubricate the linkage the rod connects to with a good spray synthetic lubricant. I like teflon lubes.

If it doesn't move, check the pressure gauge on the pump. Does the actuator hold pressure? Good. Your problem may be a rusted linkage at the rod/turbo interface. Spray the linkage with some PBBlaster rust penetrant and let sit a bit. Try again with the pump. If it moves, work it with the pump to free it up. If it doesn't move, you may have to get something to manually move the linkage until it breaks free. Then exercise it until it moves smoothly and lube as above.

If it doesn't hold pressure or leaks off slowly, you have a bad actuator and it will need to be replaced.
 

coot

Active member
Joined
Feb 29, 2008
Location
Neenah,WI
TDI
looking at a 97 Jetta
Hey all..

I'm a newbie too, with thee same dreaded PO605 code coming up... I went so far as to Jason's TDI repair in Wisconsin here, who replace all my high prsure lines... he really has this car (97' Jetta) running so much better, but..... On the way home, yep.. the CEL came back on coding PO605 at the local AutoZone.. replace ECM...???

Guess I don't understand how this car runs so well... if there is a ECM issue...?? Guess I could get used to the little orange engine pic, but...

And on that last post... Are the comments on the wastgate acctuator still realtive to the PO605...?

I'll stay tuned... light still on.!
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
I believe the P0605 often means you need a very expensive $.10 piece of tubing to replace -

 

coot

Active member
Joined
Feb 29, 2008
Location
Neenah,WI
TDI
looking at a 97 Jetta
Thanks rdkern

I did replace the hose, but still have the CEL. Is it that that code needs to be cleared with VAG-COM... Should it have cleared itself (I've read that after "X" starts... the system clears itself...??)

Car runs fine if I have to live with it...!!
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
I don't know if this is one that will clear the cel after 10-20 starts - it does need to be removed from the ecu to have the dtc cleared. Clear it to see if it's fixed. The system doesn't "clear" itself, but often the cel will go out after a certain number of starts if the condition doesn't repeat itself.
 

coot

Active member
Joined
Feb 29, 2008
Location
Neenah,WI
TDI
looking at a 97 Jetta
Yep...

I've been looking for some Vag-Com's in the area, but... ???

dtc cleared...? OK.. I know.. I'm a newbie. Not sure I'm following that abbreviation.

Makes sense that it could clear if it is being repeated...

Thanks for hang'n in there with me..!!
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
The one circled looks like the fuel line that returns unused fuel from the injectors to the ip. Shouldn't affect the boost control.

Did you get the actuator to move?
 

jettagirl98

Member
Joined
Nov 2, 2007
Location
Victoria, BC
TDI
98 Jetta TDI
thanks! I haven't tried the actuator, I'm borrowing a bike pump this week and will let you know. I've given up finding a car jack, but hopefully I will be able to see it by driving it up on the curb.
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
JG98 - Did you replace the pressure line going to the ECU, and the little line inside of it? This goes from the innercooler to the MAP inside of the ecu. A hole in it can cause the pressure deviation codes.

Coot - dtc - detected trouble code? My best guess. The codes can be stored in the ecu and not turn on the cel (check engine light). Some codes just don't throw the cel.
 

jettagirl98

Member
Joined
Nov 2, 2007
Location
Victoria, BC
TDI
98 Jetta TDI
Yes, replaced ECU vacuum hose (which incidentally did have a tear), intercooler hose, and all vacuum hoses I could find (which if I remember correctly consisted of the 3 going to the N75 valve). Also replaced the N75 valve. I cleared the codes with my OBD scanner, and still no luck. Tomorrow I'll start looking at the wastegate actuator.
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
A problem with the A3's is that you don't know if it's an overboost or underboost code. Test the actuator, and if that works, start considering if you may have an intake issue. When was the air filter last changed? If due, do it. Look down that intake to see if any mice nests or anything could be clogging it. Then the other side - intake manifold. Air restriction can cause boost codes as well, on an A4 it would be underboost.
 

jettagirl98

Member
Joined
Nov 2, 2007
Location
Victoria, BC
TDI
98 Jetta TDI
ok, I've taken a look at the wastegate acuator...it will hold pressure, and moves at about 15 psi. Does this mean it's working good? Does it need lube? Thanks!
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
It should move at about 6-8lbs. Exercise it - it's probably just a bit stubborn. Try some pb blaster(?) or whatever you use to clean up rusty parts. And use your pump to push it back and forth. Clean up the motion and it probably will be OK.

(ps, victoria is one of the gems of the continent. Love that town)
 

blizzak

Veteran Member
Joined
Oct 7, 2007
Location
Mississauga, Ontario
TDI
2004 Jetta TDI Sport Edition, Grey with 270,000 KM. 1997 Jetta TDI, 340,000 KM driven by my dad
With regards to the airbag/65535 codes that are being discussed in this thread, let me share my experience. I had these error codes:

Engine:
00575 - Intake Manifold Pressure 17-10 - Control Difference - Intermittent
65535 - Internal Control Module Memory Error 37-10 - Faulty - Intermittent
00519 - Intake Manifold Pressure Sensor (G71) 28-10 - Short to Plus - Intermittent

Airbag:
00532 - Supply Voltage B+ 07-10 - Signal too Low - Intermittent

After replacing all my vacuum hoses (even the one inside the ECU), I cleared the codes using vagcom, and none of them except the 00575 came back! Now I know this code is being caused by my wastegate being stuck closed and I am going to address that soon, but I think this should give hope to anyone who has airbag/memory error codes that typically they can be fixed by a simple vacuum hose swap. The most important thing when you are replacing your hoses is to just REPLACE THEM ALL, regardless of how any of the old ones look.
 

jettagirl98

Member
Joined
Nov 2, 2007
Location
Victoria, BC
TDI
98 Jetta TDI
ok- sprayed some teflon rust penetrant on it, it ran like a dream for about 20 minutes, then back into limp mode. Sprayed some more (in the open AND closed position), exercised it with bike pump a few times, clamped my vacuum hoses down good, and so far, so good! I bought the vehicle with this problem, so I've never actually seen what my car can do!!! So far, so good. This car has a sense of humour though, so I'm not holding my breath...thanks for everyone who helped a complete novice on her very first repair job :) :) :) (and stay tuned...as soon as I officially say it's fixed I know my car will turn on that CEL just to mess with me)
 
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