MK4 Jetta ALH no start condition Intermittent

srosey

Active member
Joined
May 7, 2014
Location
Daytona Beach Florida
TDI
2001 Jetta
I've been having this random issue with my 2001 Jetta ALH. There have been numerous times where the car will randomly shut off and have a no start condition where it is just cranking, sometimes if I vary the throttle pedal it will finally start up. I was using a key for awhile that had just the blade which was broken off of the FOB, worked well for a month or two, then the issues started. I switched to a known good key fob and the issue remained.

Things I have checked and done-

IMMO delete from Malone tuning- has stage 5 tune attached.
Relay 109 checked and replaced with a known good grey relay
Tachometer is operating while cranking- ruled out crank sensor.
No flashing key symbol on dash


Codes it threw early on :

17978- Engine Start blocked by Immobilizer
01176- Key
07-10- signal too Low- intermittent

Codes it threw after IMMO delete with same issue:

01314- Engine control module
49-10-No communications- intermittent
in both address' 17 instruments and 19 CAN gateway

Could this just be an intermittent ECM issue where the whole ECM needs replaced or just a shorted wire somewhere ?
It only happens once every couple weeks randomly at the most inopportune time
 

Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
When this happens and you try and restart it does your glow plug light work?
 

srosey

Active member
Joined
May 7, 2014
Location
Daytona Beach Florida
TDI
2001 Jetta
Malone was no help with the code. Car did the same thing again but no code this time. Which makes me wonder if this is a fuel related issue. The IP is an 11mm that was a genuine rebuilt unit put on a year ago all hoses from the firewall to pump were replaced recently. I have a brand new filter with T fitting to swap out here soon

Any other things that I could check ?
Thanks
 

Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
Crankshaft sensor can cause issues like this. Either the sensor itself or the wiring to the sensor.
 

Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
I found this thread where some discussion on this problem has been had. This is for the BRM and Bew engine.

 

Rapid Transit

Veteran Member
Joined
Oct 2, 2010
Location
SF Bay Area
TDI
03 4dr Golf GLS
The Crankshaft sensor would cause the tach to not work correct ? Even if it is the sensor or the wiring.
I had wiring/connector issue at the CPS and the tach worked fine. Car never shut down on me but was hard starting. Left me stranded for 30mins once. Bought a new sensor and was tracing out the wires/plug and plug was either loose or wires were damaged. Cars been running fine since with the new sensor as a spare in tool box.
 

A4-TDI

Veteran Member
Joined
Dec 13, 2009
Location
Québec
TDI
1.9TDI
Hello,

I have the same issue on the same car since 1 month. Also, since I have this intermittent no start condition, my glow plug light is always blinking when running when it starts ok, but runs fine. Sometimes (very rare),, the engine missed one entire révolution on highway, but never stalled. Power is ok 90% of the Time, but sometimes i expérience a noticeable loss of Power.

I also have another issues (related or not...) since 1 year : the idle is a Little rough like a gas car Who have a very small vacuum leak, even if it runs fine. Also, the water temp sensor going to the ECU is reading too low in temp.

I want to throw the codes with vagcom next saturday because this winter car is in my father's yard 300 miles from home. But I would like to have your opinion of what to check/test also in advance because i Will have only two Days to diagnose in order to order New parts if broken...

Crank sensor? Fuel pump or electronic components of pump? Needle lift sensor?

And what was the problem if the OP, finally?
 
Last edited:

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagen, 2021 Atlas,2003 Jetta 261K Sold but not forgotten
Have you scanned for codes while the CEL is on ?
Also scan for codes after you loose power and before turning the key off.
Post the results.
 

srosey

Active member
Joined
May 7, 2014
Location
Daytona Beach Florida
TDI
2001 Jetta
Thanks everybody for the replies. I still have not found the issue. I have since changed fuel filter, all lines from the firewall, T fitting, and the IP shut off solenoid thinking the plunger was sticking.
Verified there is power to the solenoid with key on.
Same results.
Car runs fine when started just is intermittently hard to start.
There have been several times where I have been stranded and it takes 30- 40 mins to finally get the car started.
Just cranks and cranks.
When it finally starts it stumbles for a little and then evens out.
IDK if me pumping the throttle pedal helps but it seems to.

I'm not getting a code for crank sensor and the tach is still working- but that is my next area of troubleshooting.
 

A4-TDI

Veteran Member
Joined
Dec 13, 2009
Location
Québec
TDI
1.9TDI
Hello :

Here's my codes after the scan :
*17655 – Needle lift sensor (G80) Open or short to Plus - P1247 – 35- 10 Intermittent

*16706 – Engine speed sensor (G28) : No signal - P0322 – 35 – 10 Intermittent

*17654 – Needle lift sensor (G80) : Implausible signal - P1246 – 35 – 10 - Intermittent
 

CopaMundial

Veteran Member
Joined
Jan 30, 2011
Location
Southeastern PA
TDI
03 Jetta Wagon 5sp (New to me Oct 2014) 03 Jetta 5sp (RIP Aug 2014)
@srosey does your car have the section of clear hose from filter to injection pump, and if so do you see air in that line?
Have you checked the Anti-Shudder Valve (ASV) operation?
You mentioned that the glow plug does come on, is that true even when it's failing to start?
 

Nevada_TDI

Top Post Dawg
Joined
Aug 17, 2008
Location
Reno, sort of...
TDI
2001 Jetta TDI
Every couple of tune flashes I get the blinking glow plug light. When I check the error code I get the IMMO code, yet the engine still runs fine.
If it were me, I would pull the cowling off and then pull the ECM. It is possible there could be in intermittent connection due possible to weather, moisture in the air.
I went through a similar situation years back, and throwing parts at the car, I should have started with the wiring.
 

srosey

Active member
Joined
May 7, 2014
Location
Daytona Beach Florida
TDI
2001 Jetta
The stock clear hoses have been changed out for solid rubber hoses. ASV is gone, car has a race pipe swapped for the EGR/ASV. Glow plug light does come on when cranking. After replacement of the crank sensor I was going to start looking into the ECU
Thanks for the replies
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagen, 2021 Atlas,2003 Jetta 261K Sold but not forgotten
The clear fuel line would show you if the fuel is holding in the lines or syphon back to the tank when the car is not running.
In this case I would look into the codes:
01314- Engine control module
49-10-No communications- intermittent
Is the ECM getting power?
 

srosey

Active member
Joined
May 7, 2014
Location
Daytona Beach Florida
TDI
2001 Jetta
Just an update for everybody.
Swapped out the CPS and that seemed to do the trick. Car took a little bit to get started but is now running and has been starting fine for the past couple days. The weird thing is that it never threw a code for the sensor and the tach was working fine the whole time.

Thanks everybody for your time.
 

srosey

Active member
Joined
May 7, 2014
Location
Daytona Beach Florida
TDI
2001 Jetta
Welp everybody I’m back to the drawing board. Today car started just fine then was idling weird- little choppy so I shut it off and tried to restart and just cranking. Anybody have any other ideas ?
check valve in sending unit will do this ?
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagen, 2021 Atlas,2003 Jetta 261K Sold but not forgotten
Did you check the clear fuel line for the bubble?
If there was air in the system it could run funny.
Shutting it down might not have enough fuel in the IP.
Did you scan for codes while it was running 'choppy' ?
 
Top