2002 Jetta ALH does not restart after running for 15 minutes or longer

[tryin2vw]

2002 Jetta ALH 540k miles, bone stock. After running the car for 20 minutes or more, the vehicle does not start again. Allow it to cool off for an hour, it starts right up. There is no CEL.

The following have been done:
New fuel filter bypassing the thermostatic valve
New fuel temperature sensor in IP
New fuel shut off valve on IP
After learning that a jumper is run from the battery directly to the fuel shut-off valve on the IP allows the vehicle to start without issue, a new 109 relay was installed.

Now after a 30 mile test drive, the same problem exists. The engine turns over but will not start, unless the jumper wire is installed from the battery to the IP fuel shut off valve.

Where should I go next?
Doug

 

[tryin2vw]

When it will not start, the fuel cut off on the IP only receives about 9.7VDC.

My VCDS scan:

Sunday,05,May,2024,13:38:59:23395
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x64
VCDS Version: 24.5.0.0 (x64)
Data version: 20240429 DS355.0
www.Ross-Tech.com


VIN: 3VWSP69M42M011724 License Plate:
Mileage: 541616 Repair Order: home


Chassis Type: 9M (1J - VW Golf/Bora IV (1998 > 2006))
Scan: 01 02 03 08 15 16 17 19 22 29 35 36 37 39 46 47 55 56 57 75
76

VIN: 3VWSP69M42M011724
-------------------------------------------------------------------------------
Address 01: Engine Labels: 038-906-012-AGR.clb
Part No: 038 906 012 FD
Component: 1,9l R4 EDC G000SG 4102
Coding: 00002
Shop #: WSC 00066
VCID: 57B774EAB556072E52-4AE6
3VWSP69M42M011724 VWZ7Z0A3842382

No fault code found.
Readiness: 0 0 1 1 1

-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 1C0-907-37x-ABS.lbl
Part No: 1C0 907 379 C
Component: ABS FRONT MK60 0103
Coding: 0004097
Shop #: WSC 00066 000 00000
VCID: 2A51FD1E86A44AC63D-5120

No fault code found.

-------------------------------------------------------------------------------
Address 15: Airbags Labels: 6Q0-909-605-VW5.lbl
Part No: 6Q0 909 605 F
Component: 04 AIRBAG VW6 0202 0004
Coding: 12340
Shop #: WSC 00066
VCID: 3A71CD5E2604FA464D-5102

1 Fault Found:
00588 - Airbag Igniter; Driver Side (N95)
32-00 - Resistance Too High

-------------------------------------------------------------------------------
Address 16: Steering wheel Labels: 1J0-907-487-A.lbl
Part No: 1J0 907 487 B
Component: Lenkradelektronik 0002
Coding: 00008
Shop #: WSC 00066
VCID: 3065EF76F0783016F3-51B2

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments Labels: 1J0-920-xx5-17.lbl
Part No: 1J0 920 906 L
Component: KOMBI+WEGFAHRSP VDO V07
Coding: 07232
Shop #: WSC 09519
VCID: 3163EA72FB72391EFC-5102
3VWSP69M42M011724 VWZ7Z0A3842382

2 Faults Found:
01314 - Engine Control Module
49-10 - No Communications - Intermittent
01304 - Radio
49-00 - No Communications

-------------------------------------------------------------------------------
Address 19: CAN Gateway Labels: 6N0-909-901-19.clb
Part No: 6N0 909 901
Component: Gateway K<->CAN 0001
Coding: 00006
Shop #: WSC 00000
VCID: 70E52F7630F87016B3-5102

2 Faults Found:
01314 - Engine Control Module
49-10 - No Communications - Intermittent
01304 - Radio
49-00 - No Communications

-------------------------------------------------------------------------------
Address 46: Central Conv. Labels: 1C0-959-799.lbl
Part No: 1C0 959 799 C
Component: 1H Komfortgerát HLO 0003
Coding: 00258
Shop #: WSC 00066
VCID: 3777D46A1516E72EB2-4AE6

Subsystem 1 - Part No: 1C1959801A
Component: 1H Tõrsteuer.FS KLO 0002

Subsystem 2 - Part No: 1C1959802A
Component: 1H Tõrsteuer.BF KLO 0002

Subsystem 3 - Part No: 1C0959811A
Component: 1H Tõrsteuer.HL KLO 0002

Subsystem 4 - Part No: 1C0959812A
Component: 1H Tõrsteuer.HR KLO 0002

10 Faults Found:
01330 - Central Control Module for Central Convenience (J393)
53-10 - Supply Voltage Too Low - Intermittent
00928 - Locking Module for Central Locking; Front Driver Side (F220)
54-10 - Incorrectly Equipped - Intermittent
00929 - Locking Module for Central Locking; Front Passenger Side (F221)
54-10 - Incorrectly Equipped - Intermittent
00930 - Locking Module for Central Locking; Rear Left (F222)
54-10 - Incorrectly Equipped - Intermittent
00931 - Locking Module for Central Locking; Rear Right (F223)
54-10 - Incorrectly Equipped - Intermittent
01331 - Door Control Module; Driver Side (J386)
53-10 - Supply Voltage Too Low - Intermittent
00912 - Window Regulator Switch; Front Left (E40)
27-10 - Implausible Signal - Intermittent
01332 - Door Control Module; Passenger Side (J387)
53-10 - Supply Voltage Too Low - Intermittent
01333 - Door Control Module; Rear Left (J388)
53-10 - Supply Voltage Too Low - Intermittent
01334 - Door Control Module; Rear Right (J389)
53-10 - Supply Voltage Too Low - Intermittent

End-------------------------(Elapsed Time: 04:57)--------------------------

 

[tryin2vw]

after experimenting for a bit, I was finally able to generate the following relevant codes:

Sunday,05,May,2024,14:05:12:23395
VCDS Version: Release 24.5.0 (x64) Running on Windows 10 x64
www.Ross-Tech.com

Address 01: Engine Labels: 038-906-012-AGR.clb
Control Module Part Number: 038 906 012 FD
Component and/or Version: 1,9l R4 EDC G000SG 4102
Software Coding: 00002
Work Shop Code: WSC 00066
Additional Info: 3VWSP69M42M011724 VWZ7Z0A3842382
VCID: 57B774EAB556072E52-4AE6
2 Faults Found:

17946 - Fuel Shutoff Solenoid (N109)
P1538 - 35-00 - Open or Short to Ground
18009 - Relay for Supply Voltage Terminal 30 (J317)
P1601 - 35-00 - Implausible Signal

Readiness: 0 0 1 0

thoughts?

I will be trqcing the solenoid wire back to the ecm

 

[roder]

It sounds like it could be the infamous ALH hot start issue.

99 ALH hot start issue

sold a 99.5 MK4 jetta to a friend, 240k on it, 5spd one owner car that was amazingly clean. cold it starts right up, once its hot and want to start again it will crank for about 4 seconds before starting. i am guessing it's fuel related however no lift pump here so not sure what to do

forums.tdiclub.com

If so, it can be fixed with MPSS and EDCSuite15p, or with a tune from Malone.

 

[tryin2vw]

It sounds like it could be the infamous ALH hot start issue.

99 ALH hot start issue

sold a 99.5 MK4 jetta to a friend, 240k on it, 5spd one owner car that was amazingly clean. cold it starts right up, once its hot and want to start again it will crank for about 4 seconds before starting. i am guessing it's fuel related however no lift pump here so not sure what to do

forums.tdiclub.com

If so, it can be fixed with MPSS and EDCSuite15p, or with a tune from Malone.

Can you direct me to a thread or two so I can understand the issue? After 540k miles, this is a new problem to me.

 

[jmodge]

Not quite the same issue, but several years back mine would lose boost after about 10 miles of travel, less when warm, no boost almost immediatly when hot. I found it to have a working n75 signal when the engine was off but non functioning when the engine was running. Turned out to be the ecu. Can you get another to try? I think that hot start issue was just those early ALH's

 

[burpod]

try unplugging the coolant temp sensor when the car is hot and see if it still has the issue

 

[tryin2vw]

try unplugging the coolant temp sensor when the car is hot and see if it still has the issue

I will try that to tomorrow.

One other issue that was noticed: I was jiggling wires looking for a loose/broken wire when my glow plug light began flashing. I replaced the glow plug harness several years ago and it is in good condition, as far as I can tell without unwrapping tons of cloth tape. I could not get the symptom to replicate.

 

[burpod]

flashing glow plug light is usually a problem with the pump or pump electronic

 

[roder]

Can you direct me to a thread or two so I can understand the issue? After 540k miles, this is a new problem to me.

The fueling tables have an error where they ECU will not fuel under 250 cranking rpm with the engine warm. If you have a new battery and a new starter, it will usually crank fast enough that the issue does not occur

The link I posted is anchored to an enthusiast that explains the problem. See the quote above.

If I understand correctly, the map/table in question has an axis that is based on engine coolant temp. If you pull the sensor, that map wouldn't locate the too low fueling values to start.

 

[tryin2vw]

The link I posted is anchored to an enthusiast that explains the problem. See the quote above.

If I understand correctly, the map/table in question has an axis that is based on engine coolant temp. If you pull the sensor, that map wouldn't locate the too low fueling values to start.

I have a relatively new battery and the starter is only 2 years old. The car cranks well and usually starts up quickly when cold, or I jumper the fuel cut off switch on the IP.

 

[P2B]

The link I posted is anchored to an enthusiast that explains the problem. See the quote above.

If I understand correctly, the map/table in question has an axis that is based on engine coolant temp. If you pull the sensor, that map wouldn't locate the too low fueling values to start.

The issue applies to 99.5 cars only and is irrelevant in this thread.

 

[burpod]

The issue applies to 99.5 cars only and is irrelevant in this thread.

true. although its odd, and i'm not sure why there are two start IQ maps, but in the 2000+ cars, there is one map with the "hot start fix" applied, but another start map that doesn't have it. not sure what conditions would cause it to use the non-fixed start map. perhaps it's a start map in the event of some sensor error? have never figured that out... in the PDs, there are different start maps for altitude and oddly enough some BEWs had the "hot start" bug. no idea how that would have crept back in there lol

 

[tryin2vw]

try unplugging the coolant temp sensor when the car is hot and see if it still has the issue

I used my VCDS to verify the temperature and it was reading correctly. I replaced the coolant temperature sensor anyway because it is not hard to do and it is an inexpensive part. (The o-ring was hard, breaking in half as it was removed, so a leak was probably going to happen in the near term)

It did not fix the issue.

The following has been done:
New fuel filter bypassing the thermostatic valve;
New fuel temperature sensor in IP;
New fuel shut-off valve on IP;
New 109 relay;
New coolant temperature sensor.

 

[Zak99b5]

Did you trace the fuel shut off wire yet? That's the first thing I'd be looking at in your situation.

 

[oilhammer]

Does the ECU see cranking RPM in the data when it won't start?

I see some ECU communication faults... makes me think that the controller is getting hot or something, but then you'd think it would stall once warm too.

Other thing could be the ignition switch moving PAST the 'run' position while cranking.... that's more a thing on older Japanese cars, but you could see if this is the case by watching that cranking data.

The ALH needs very little to run.

I am also assuming it is cranking normally when this happens, and not super fast like it isn't compressing any air?

 

[tryin2vw]

Did you trace the fuel shut off wire yet? That's the first thing I'd be looking at in your situation.

To the best of my ability, the wire has no breaks or chaffing marks. It is to rain tonight so nothing will be done, but if the weather clears, I will cut the wire and splice a new, known good wire in place to eliminate the possibility.

Does the ECU see cranking RPM in the data when it won't start?

I see some ECU communication faults... makes me think that the controller is getting hot or something, but then you'd think it would stall once warm too.

Other thing could be the ignition switch moving PAST the 'run' position while cranking.... that's more a thing on older Japanese cars, but you could see if this is the case by watching that cranking data.

The ALH needs very little to run.

I am also assuming it is cranking normally when this happens, and not super fast like it isn't compressing any air?

This is what I am thinking, the ECU is getting hot. Once pulled in, the relay on the ECU will stay in until the vehicle is turned off. Once turned off, something is not allowing the relay to fully connect, causing a low voltage to the cut-off valve preventing it from energizing. If the ECU is bypassed and wired directly from the batter to the IP cut-off valve the car starts up normally.

It is cranking normally but without fuel. It has good compression.

 

[oilhammer]

Well.... 10 seconds with a scan tool would let you know if the ECU sees the CKP signal or not.

 

[P2B]

Once pulled in, the relay on the ECU will stay in until the vehicle is turned off. Once turned off, something is not allowing the relay to fully connect, causing a low voltage to the cut-off valve preventing it from energizing.

There is no "relay on the ECU".

Have you checked voltage to the fuel shut off solenoid with key on? Voltage at the ECU pin (T121/120) with key on?

 

[tryin2vw]

There is no "relay on the ECU".

Have you checked voltage to the fuel shut-off solenoid with key on? Voltage at the ECU pin (T121/120) with key on?

The voltage to ground at the fuel cut-off when cold and key on is 12.7VDC. The voltage to ground at the fuel cut-off after running for about 25 minutes, turning the car off, and then key on is 9.7VDC The car does not stat. I will check Pin T212/120 when I can if not raining.

 

[oilhammer]

That indicates to me that you have a bad connection in that circuit, that builds resistance with heat. It doesn't quit running like that, because a solenoid doesn't require full voltage to remain open... but I admit I do not know what the ECU's output logic is on controlling that solenoid. Of course, I would think even 8v would be enough to work the plunger, but obviously not.

As a comparison: the compressor clutch on that car, which like the stop solenoid on the pump is also an electro-magnet, gets a quick shot of ~12v to pull it in, then the FCM levels it out to around 8v to hold it there.

 

[P2B]

That indicates to me that you have a bad connection in that circuit, that builds resistance with heat.

Bentley shows that circuit running through a 10 pin connector (I assume the one on top of the starter) then to the ECU.

That connector would be the first place to look for trouble.

 

[tryin2vw]

Bentley shows that circuit running through a 10 pin connector (I assume the one on top of the starter) then to the ECU.

That connector would be the first place to look for trouble.

From the 10-pin to the fuel shut-off has good continuity when cold and warm, wiggling and giggling. Testing the female side, shows 9.7 V when the problem is occurring, so it is closer to the ECM end of things

 

[rustman1984]

From the 10-pin to the fuel shut-off has good continuity when cold and warm, wiggling and giggling. Testing the female side, shows 9.7 V when the problem is occurring, so it is closer to the ECM end of things

Have you figured out your issue yet? I am currently looking up how to diagnose a crank no start myself and I came across this thread. This car had an auto trans to manual swap a year ago and wouldn't start soon after. They put in a manual ECU with a kermaTDI tune. I still have the old one. I am also thinking about ECU and injection pump issues. They seller of the car also had removed the injectors and ultrasonic cleaned them without dissemble. It makes me wonder if there's a needle lift sensor issue going on but I have not idea what those symptoms are. Any woot, I'm curious to see what your solution is and see if it could apply to my case. Good luck

 

[tryin2vw]

I will be working on this in the AM. Unexpected company showed up diverting my attention.

 

[tryin2vw]

With the engine having run for 20 minutes, fully warmed, up and the problem occurring, the wire from the ECU to the IP ohms at 0.1-0.2ohms, well within the capabilities of my meter for good continuity.

I removed and replaced the ECU from a different TDI (same part number) with the immobilizer still active, the engine starts properly then dies due to the immobilizer. So this problem is the ECU. I will be having an immobilizer delete done by Ian at Reflect Tuning in Winston-Salem, because he is relatively local, no shipping needed, and it can be done relatively quickly.

See the update below

 

[P2B]

17946 - Fuel Shutoff Solenoid (N109)
P1538 - 35-00 - Open or Short to Ground

An intermittent short to ground could have taken out the driver in the ECU. Hope it doesn't happen again

 

[tryin2vw]

This is still an ongoing problem. I have replaced the ECU, the 109 relay the wire from the ECU to the fuel cutoff switch on the IP and cleaned all of the grounds under the hood.

When the engine is first started, no problems. Once the engine has run for 15-20 minutes, it will not restart without providing power directly to the fuel cutoff on the IP. Power from the relay block on the battery to the 109 relay appears good.

Relay block issues and surrounding grounds are being investigated. It appears to be a connection that gets warm and changes resistance, not allowing the 109 relay to provide enough ECU and fuel cutoff switch power.

 

[rustman1984]

This is still an ongoing problem. I have replaced the ECU, the 109 relay the wire from the ECU to the fuel cutoff switch on the IP and cleaned all of the grounds under the hood.

When the engine is first started, no problems. Once the engine has run for 15-20 minutes, it will not restart without providing power directly to the fuel cutoff on the IP. Power from the relay block on the battery to the 109 relay appears good.

Relay block issues and surrounding grounds are being investigated. It appears to be a connection that gets warm and changes resistance, not allowing the 109 relay to provide enough ECU and fuel cutoff switch power.

Did you do the immobilizer delete?

 

[tryin2vw]

Did you do the immobilizer delete?

Yes, the immobilizer delete was done.