... IP's Harness wires to the G149 Modulating Piston Displacement Sensor

OK, I think I have a real challenge here.
[1] First, we had to go internal on our IP to solve its 3-week NO START problem.
[2] My INDY VW/Audi shop "tweaked" it with the latest ver. of VAG-COM from Ross-Tech.
[3] But the computer keeps throwing off code P1562... about every 2 weeks!
[4] I have completed resistance tests on these pin pairs looking into the IP's 10-conductor harness cable:
.....1-to-2 and found ~6 ohms
.....2-to-3 and found it was open... no continuity!?
.....5-to-6 and found ~1 ohm
My take on the results of my reading above on pins 1, 2, & 3 is that
there is a good chance the wire in the harness from pin #3 might be failing
and loses continuity after the car/engine/IP fully warms up!
.................
I'm pretty good at slicing/dicing and repairing harnesses,
so I'm thinking about the following diagnostic/(possible repair) steps:
(a) cutting off the harness cable about 3 inches from the IP...
leaving enough to splice to later (hopefully),
(b) measuring resistance from that point into the IP to
see IF I get the same readings as above and
.....also before cutting, take readings between pins 4-to-7
( these run to my new FTS on my last IP internal inspection )
.....to compare after cutting the harness cable.
My logic in this is that IF these conductors appear good from this point looking into the IP,
then I will conduct similar (but individually end-to-end) continuity tests on each of the 7 conductors
that run into the IP's QA/FTS/Modulating Piston Displacement Sensor (MPDS) in this bundle
harness from the cut back to the pins in the connector...
and in doing this I will test each wire individually and
bend/flex the short cable to see if continuity is restored and/or broken!?
..............
IF I do find a broken/unreliable wire pin #3 and/or other conductors,
then I will make a reliable repair of the existing harness bundle or rebuild a
new harness to and spliced into the 10-conductor in-line connector!
Q1 - Can anyone follow my too lengthy a discussion which helps me to test the logic of such diagnostics?
Q2 - Does anyone have suggestions for other checks/tests that I should try first.
...............
Yes, since I have been into the IP twice before I'm even thinking I might open up the top of the IP and
see IF I can conduct resistance readings for each of these same 7 conductors from the QA/FTS/MPDS
circuit board assembly back out to the pins in the 10-conductor connector!
This would also let me check again for wear metal filings that stick to the magnet on the bottom of the QA assembly!
Your thoughts/suggestions PLEASE,
P.S. - See page No. 66/4 of the Wire Diagrams.
I have a PDF of this wiring IF you want me to send or try to POST it here on the FORUM!
Sam Ross

I think you already know this, but that 2-3 reading is a problem, according to the Bentley-
Using a multimeter , check the Diesel Fuel Injection Pump terminals 1 to 2 and 2 to 3 for resistance.
Specified value: 5 to 7 Ω
If the specified value was not obtained:
Replace the Diesel Fuel Injection Pump . Refer to Diesel Fuel Injection, Repair Group 23.
If the specified value was obtained:
Checking wiring
Before you cut the wires close to the IP you can use a small probe (sewing needle?) to pierce the wire, then recheck resistance.
I also noted when I looked up the P1562(QA), it pointed to a test for terminals 6-5 to read 80-120 Ω
EDIT- After posting this I'm questioning that 80-120 for pins 5-6. It seems the old ebahn Bentley says something very different

BobnOH said:

I think you already know this, but that 2-3 reading is a problem, according to the Bentley-
Using a multimeter , check the Diesel Fuel Injection Pump terminals 1 to 2 and 2 to 3 for resistance.
Specified value: 5 to 7 Ω
If the specified value was not obtained:
Replace the Diesel Fuel Injection Pump.
Refer to Diesel Fuel Injection, Repair Group 23.
If the specified value was obtained:
Checking wiring
Before you cut the wires close to the IP you can use a small probe (sewing needle?)
to pierce the wire, then recheck resistance.
I also noted when I looked up the P1562(QA), it pointed to a test for terminals 6-5 to read 80-120 Ω
EDIT- After posting this I'm questioning that 80-120 for pins 5-6.
It seems the old ebahn Bentley says something very different

Click to expand...

Bob,
Thanks for your response... and yes, you are correct that I have eBahn and
access to it's so called "repair" procedures...
but I have become skeptical about many of their procedures...
and when they do not seem interested in correcting the obvious mistakes,
well that makes me even more skeptical!
So I'm anxious to see IF I'm correct about at least one conductor inside this
harness is unreliable and the best way is to do the same checks near to where the harness cable enters the IP...
and IF I go ahead and open the top of the IP,
maybe I can check continuity from this point by strippin off the cable's outer insulation and
then needle-pierce each wire inside using my meters special piercing needle test lead...
and with the top off the IP, test each wire from just outside the IP where the cable enters the IP's case
to where these wires connect to the QA assembly circuit board inside the IP!
I'll let all know what I decide to do.
IF I DO THIS, I will perform individual resistance measurements on each wire...
from the center pierce-points to both the pins in the 10-pin connector...
AND inside the IP on the QA circuit board!
I am pretty good at splicing and restoring cables by using multiple layers of slightly different ID shrink tubing...
but I agree, it makes more sense to first strip off the outer sheathing of the cable and individually pierce test each conductor/wire!
Thanks again... for discussing it first gives me confidence that I will choose the best procedure eventually!
Sam

...I found a GREAT 32-pg REFERENCE that helps me with this THREAD!

Yes, I have found a GREAT 32-pg Reference that helps me understand the input
sensors and the actuators in/associated with the TDI VE series Injection Pumps IPs...
and it was right under my nose here on this FORUM at:
http://pics.tdiclub.com/data/529/13523tdi-technik-eng.pdf
Now to learn more about the " IP's Case Pressure " how best to test & adjust
this pressure and what it is suppose to be at a set RPM?
Regards,
Sam Ross

...I found an even GREATer 64-pg+ BOSCH REFERENCE on VE series IP(s)

IF you click on this link: http://gnarlodious.com/vanagon/Bosch_Pump/Bosch_VE_Pumps.pdf
before it disappears, you should go directly to (IMO) the best OnLine FREE reference booklet from BOSCH... at least that I have seen thus far.
I was readily able to download this ~1.6mb PDF file!
It is titled:
....."Diesel-engine management"...
....."Diesel distributor fuel-injection pumps... VE"
....."Technical Instruction"
I had found older versions of this same booklet and they were "graphic-based" only...
which means you could not search the 64-pages via text searches!
This 4th edition is dated 1999 and includes (starting on pg 54) a discussion of the VE-EDC version
that I believe to be installed in our VW ALH-VE engine powered TDIs
I found the "1.9L Industrial TDI" reference in my POST above here in this FORUM and it discusses the entire engine theory of operation...
But this reference is only on the VE series IP(s)...
and I do NOT believe it is POSTed in the "pic" section of TDIclub.com WebSite... yet!?
IF YOU READILY KNOW HOW TO POST SUCH REFERENCE MATERIALS HERE, PLEASE DO SO BEFORE THIS DISAPPEARS AS OFTEN HAPPENS!!
P.S. - I found that our 10-pin InLine harness connector to the IP was literally slipping loose due to a broken plastic lock "detent"...
and once was found completely OFF.
The 2 pieces to this InLine connector (male & female) are apparently no longer available as individual parts...
and so I presume one must purchase the entire harness at some rediculous price in order to replace these "OE" !
I will start trying to find a salvage connector... or alternative (Mercedes?) that is more durable!
Regards,
Sam Ross
Thanks to "BobnOH" below for posting this valuable file here on our FORUM... before it went away...
now we have two very good reads on VE-E pumps in our VW(s)!

Here you go, I like it (well haven't actually read it yet)
http://pics.tdiclub.com/showphoto.php?photo=79655&title=bosch-ve-pumps&cat=516
Or go to the photos gallery and look under Technical Items.

2003 VW Jetta 1.9L TDI Cranks over but does not start

Hello I really really need help on a diagnosis. I own a 2003 vw jetta 1.9 liter tdi. Okay so this is what happened. I drove to the store one day with a half tank of fuel and shut the car off to go inside. I came back out and tried to start it but it just cranked and cranked but wouldn't start. So I tried to jump start it aND it still wouldn't run. All accessories worked fine and lights were bright. I had my car towed to a local mechanic and he couldnt provide a diagnosis. I have always used the same kind of fuel since I've had it. I turn the key to the on position and you can hear a click beneath the hood, which I believe is the fuel shut off valve, but I don't hear a hum or buzz from the in-tank sending unit. So I replaced the sending unit, cleaned every ground connection on the car, verified all fuses on driver's side door panel, cleaned cabin air filter and the air intake filter, charged battery, bled fuel system, primed the injection pump itself, filled the fuel filter with fuel, and pulled all relays and reconnected them to ensure good connection and despite my efforts it still won't start. It's been sitting 4 months and all I have learned is that the injection pump is pumping fuel from the fuel filter into the injection pump but eventually the filter becomes empty yet the injection pump still has fuel inside. Now what I'm about to describe seems like it must be at least part of the problem. This IP wire harness, was taken off and immediately put back on. Except when I got it back, on the bottom right hand side of the harness there is fuel dripping very slowly when being cranked over. So with that being said I also would like to mention that the mechanic did not torque the bolts to the correct torque setting.(This was worked on after the initial breakdown) My father is an AC Delco certified mechanic so he assisted me in taking the harness off to tighten it down correctly. When we removed the bolts we found that both O-ring gaskets, that lie between the IP and the harness, were severed. Now I understand that if the seal it broken between the two then air is getting introduced into the fuel system. Thus, preventing the IP to build enough pressure for the vacuum it creates when the car is running. I ordered new O-rings for the harness piece but there was also something else weird. When I unplugged the other end of the IP harness connector, there was a puddle of fuel sitting inside where the two harness connectors join. Using logic, this tells me that there is absolutely no way there was a good connection between the two. I had driven this car for about 7 months and had absolutely no problems with it. The previous owner provided receipts from scheduled maintenance repairs that date all the way back to when it was purchased brand new. So this assure me that the car was taken very good care of. What I cannot figure out is why it suddenly wouldn't start one day. I hope that replacing the O-rings and all gaskets along with drying out the fuel between the harness connectors solves my problem. After doing this I plan on filling the fuel tank up along with the fuel filter, prime the IP with fuel, then cracking the injector and cranking the engine over until I see fuel coming out of the injector and no more air in the fuel lines. I will be trying this on a fully charged battery. I'm sorry this is so lengthy but this is my last attempt at fixing this myself before I take it to a shop. Could anyone assure me that I'm heading in the right direction please? Thank you!

Internet diagnosis;
Leaking fuel also indicates air getting into fuel system. Find the leak and repair. If it's the pump leaking they do sell a gasket kit. While you're in there check for wear. Use a good write-up for doing that, if that's what you do.
injection pump reseal: leaking seal replacement- Bosch VE model

one long run-on paragraph is a pain to read. try to break it up next time into more manageable bits... its also a 6 year old thread, you probably should have made a new one but here goes:

there is no in tank fuel pump on a stock 2003, its just a fuel level sensor basically. the injection pump draws its own fuel from the tank. sometimes a lift pump is added on heavily modded TDIs to keep up with the injection pumps fuel demand but im sure you dont have one.

i dunno if relay 109 is applicable here as you said that the pump does suck fuel in... but does the glow plug light turn on for a second when you turn the key on? if not - that is an indicator of a bad relay 109. you can also jump the fuel shut off solenoid (n108? i think) to rule that out. the plunger of that can stick as well.

the whole system needs to be sealed. air intrusion at the fuel filter "T", a broken supply line, or an open seal on the pump will prevent it from priming and working properly.

not entirely sure how you got fuel inside the connectors... but yeah, thats not ok either... lol

are you 100% sure that nothing was damaged in the pumps internal wiring in all of your fiddling with it? if i were in your situation, i would take a known good injection pump and install it... they show up in the classifieds regularly, and some of the nice ppl here will even let you borrow a known good one with an appropriate deposit.

BobnOH

I use T pins to pierce wires.
The T top gives you a good place to clip alligator clamp test cables and makes it easier to push the pin into the wire.
Wally World has them, only a few bucks for a pack.

I'm impressed with you gents for reading that paragraph. I just couldn't do it.

KLXD said:

I'm impressed with you gents for reading that paragraph. I just couldn't do it.

Click to expand...

Makes two of us.

KLXD said:

I'm impressed with you gents for reading that paragraph. I just couldn't do it.

Click to expand...

To be honest I skimmed through it.
I followed the bulk of the testing but the analysis is above my level.

^^ditto^^
Did get he drove for 7 months no problem, drove to the store, wouldn't start.

BobnOH said:

^^ditto^^
Did get he drove for 7 months no problem, drove to the store, wouldn't start.

Click to expand...

So, bad neighborhood- don't drive to that store?