[Dowdskees]

ok so i just bought this 2001 Passat. originally i had no power to the fuel pump but the fuel pump is functional i know this by putting 12v to it. I replaced the fuel pump relay, it fired up for a second and by a second i mean like one second. I'm also having trouble getting codes from the ECU. when i turn the ignition to the run position it says no link to the ECU. but every once in a while when i turn the ignition to run then off position i can get the scanner to read the ECU and these are the codes that come up. by the way they are pending codes i have no CEL.
18507- missing message from ABS controller
17833-Evap short to ground
17880-Evap leak detected
17843- Sec airinjection pump short to ground
17938-cam position sensor
17829-secondary air injection pump short to ground
17923-intake manifold valve
17529-O2 Sensor
17525-O2 Sensor
17949-Fuel pump relay

when i put the new fuel pump relay in as i said it kicked and coughed for a second. i checked with a Multimeter at the fuel pump connector for power and had 12v. after i ran for a second i checked again and it has really low voltage during cranking and no voltage in ACC. im trying to figure out why the relay keeps frying. i bought a new one but to save money on buying new relays i need to figure out what is causing it to fry the relay. As well as intermittent signal from the ECU. I think the ECU is ok only because i can still get codes from it even though they are intermittent. theres a connnection issue i believe but i havent wire traced it enough to see where it gets power from and what turns it off an on. I want to say somethings wrong with the ignition switch in the steering column or the relay in the ECU box under the hood but i'm not sure how to check the relay in the ECU box. I dont know what poles on the relay to excite with 12v to see if the relay is closing or not. also when i hooked up the scanner and while it was trying to read the ECU i get a message in the message thing on the dash saying STOP and the Coolant light comes on. I removed the driver side Cam position Sensor and OHM checked it and got nothing its done so i know that it needs replacement, will be checking the passenger side soon, but that shouldnt keep the car from starting it would only make it run rough and rich from what i have read.
so basically i have no power to fuel pump, no spark, not sure if there is power to the fuel injectors haven't checked. my question is how can i diagnose why OBDII port is telling me there is no connection to the ECU intermittently. there is definitely constant power to the OBDII port because the scanner stays on no matter the position of the key in the ignition. only way i can get the codes is turn the ignition to RUN, switch it to OFF, jiggle the key in the OFF position, and sometimes get it to read the Engine codes but nothing else, not the Comfort control module not the Tranny module nothing else.
hopefully someone has some insight on where to go from where i'm at. I'm new new to VW, i've owned a 2000 VW Golf in the past but only had a problem with the temp sensor which was an easy fix, not this many issues so i'm definitely stumped.

SO! please anyone give me some feedback even if you think it may not be good info i would love to hear what you have to say because like i said i am new to the VW life. short of buying a new ECU or Comfort Control Module any cheap fixes would be nice. oh yeah and the sunroof doesnt work and the driver door doesnt lock remotely but will with the key. IDK if that throws any red flags but there ya go. any wiring diagrams in english would be greatly appreciated or a book other than Chilton to reference would be nice.

 

[Dowdskees]

I forgot to add that its the 2.8L V6 with auto trans

 

[Emry]

Testing relays is very easy. Each relay usually has 4 ports. You simply connect the positive and negative battery cable to those two ports and observe whether the relay clicks. To find the relay layout, just search this forum. There are many threads about it.
I also assume that you have checked the fuel pump fuse and it is ok.

 

[Dowdskees]

yup checked the fuse and the relay they're good. i cant figure out why the ECU isnt communicating with my scan tool. im almost positive thats why i have no spark. do you know which wire in the ignition is supposed to power up the ECU?

 

[2002GLXV6]

Here are the wiring diagrams. http://vwts.ru/electro/wd_p_00.pdf

Ignition switches are cheap and fairly easy to install, so why not start there?

Also, your codes show a fault with the ABS controller. ABS modules are known to cause other issues when they go bad. Try pulling the ABS module and see if that helps. There are DIYs on how to do this. CHEAP Bosch 5.3 ABS REPAIR VW Passat Audi A4 A6 A8 S4

Clearing up your list of shorts to ground wouldn't hurt either.

 

[Tomvw]

Disconnect the ABS module and leave disconnected until after you have the engine running properly.
If you regain access to the other modules you can be sure the ABS module is faulty and should be sent out for repair.

Scan and post the codes.
Clear codes, and re-scan and post the codes.


While cranking the engine: (With everything connected, including the fuses)
What is the voltage between ground and each side of fuse #28 ?
What is the voltage between ground and each side of fuse #29 ?
What is the voltage between ground and each side of fuse #34 ?

With the ignition on:
What is the voltage between ground and each side of fuse #32 ?
What is the voltage between ground and each side of fuse #7 ?
If they are low you probably have a bad ignition switch, check term 15.

 

[FrescoGreen01.5]

The book with the most information is the Bentley manual, about $100, but the size of a city yellow pages, hundreds of pages of schematics alone.

Per post #5, disconnect your ABS controller until other issues are solved. The ABS is controller is a known failure point and the failure will prevent communication with the ECM. It's a chore to remove, but can be rebuilt for $100-150; don't try to fix it yourself, you'll just destroy it.

The ECMs, by contrast, are very robust and very seldom fail. Virtually all the codes you list would be caused by a blown (or otherwise defective) fuse 34. It powers several valves, the oxygen sensors, etc. The ECM will see "no power" for a given relay, valve, etc, as a short to ground. Note that the ECM actually switches the negative side of the valves, relays, etc--the positive side will be powered whenever the ignition is on. You could check for +12 volts on the green/yellow wire on any of several solenoid valves--the green/yellow wire is the load side of fuse 34.

You do mention "ACC" position in your post. Note that these cars do not have an Accessory position for the ignition switch. There's a little detent between the key removal position and the "run" position where the steering wheel is unlocked, but electrically nothing changes there. Electrically, there is just run and start.

 

[Dowdskees]

ok good information for the future thank you everyone!!!
update though. i jumped the fuel pump relay connection and got the car to start, runs rough and will only run with a little foot on the accelorator pedal. the head gasket is bad leaking in the engine compartment and out the exhaust. still no connection to my scanner when engine is running so i think some wiring is faulting there. was still amazed that the engine would run so i'm happy. going to remove the heads and replace the gaskets may have the heads resurfaced if need be. still though need to figure out why i cant get communication to my scanner via the OBDII port. got to be a wiring issue im sure because from what i read (and i can be wrong) the engine shouldnt fire without the computer's signal. but with the cam sensor not showing any sort of OHM signal it will run rich and the O2 sensors reading wrong i know that will make it run rich which makes sense because i have to give it gas to keep it running. but the only way to makek this car run is with the fuel pump relay jumped with a jumper wire. when i get this car into my garage finally and begin to tear things apart i will go through everyones input thank you so much!

 

[Dowdskees]

ok been working just recently had time to tinker with it. i dont know why i didnt do this before but, i jumped the fuel pump relay so i had direct power to the fuel pump which testing with a voltmeter had power to the ignition system as well. car fired right up!! but head gaskets are bad yay me. not sure if the heads are not allowing it to idle or the cam sensor and mixture of bad O2 sensors are causing it to not idle tough to diagnose without fixing one issue at a time. so doing a head job next. still why is the fuel pump relay not kicking on?

and also i cant figure out why i get intermittent signal to the ECU. correct me if im wrong but the computer does run the cars ignition system right? without the ECU running the car shouldnt fire right? if so i just have a connection issue from my OBDII port connector in the floor to the ECU?

 

[Dowdskees]

by the way i did try disconnecting the ABS module but still no connection to ECU. (is it ECU or ECM? i always see both)

 

[Tomvw]

"Engine Control Unit" or "Engine Control Module" stand in the corner of a round room and take your pick.

 

[Dowdskees]

So Tom i see you on this forum quite a bit so i believe you may know this question, with my head gaskets leaking and i havent started the tear down yet, but with 202,000 ODO would it be wise to buy known running but used heads or should i get mine resurfaced?

 

[Tomvw]

You would first need to establish that you have faulty heads before considering repair or replacement.

 

[Dowdskees]

how do you remove the timing gear from the cam shaft? do you need a puller to pull it off because once i got the bolts free theyre stuck on pretty good and i tried shocking them with a brass hammer but that was completely useless

 

[Tomvw]

CAUTION: SERIOUS DAMAGE TO VALVES ETC COULD OCCUR.
To remove the cam pulleys, loosen the bolts a couple of turns and use a 2 or 3 prong puller.

You should carefully study all procedures related to timing belt and CCT replacement, before disconnecting anything in that area.

I suggest you properly diagnose the issues, and establish that the heads need to be removed (unlikely) before removing them.

 

[Dowdskees]

yeah im worried that the previous owner did something wrong. i ordered the bentley manual and its on its way so ive halted my forward motion on this because the notch that tells me its on TDC on the crank pulley doesnt make sense to where the valves are on Cylinder 1. the exhaust valves are in their fullest extension on TDC which in my recent experience with engines which is a good amount, shouldnt be the case. the cylinder valves on cylinder 1 should be both in the closed position when its on TDC in my opinion and its not the case however the big holes on the Timing gear are facing eachother if that makes sense. the oblong shaped rings behind the bolt that holds the timing gear on. they are facing eachother but the exhaust valves are open.

i know for a fact that the head gaskets are leaking, i.e. white smoke out the tailpipe and in the engine bay when running. and if not it still needs to be torn down in my opinion because i need to figure out where the leak is. i dont think the thermostat was opening because the water coming out of the radiator was bright green and the water that came out the engine was brown. no circulation i think.

 

[Tomvw]

You obviously have no understanding of engine timing, I suggest you get it fixed by someone who does.

 

[Dowdskees]

i do have an understanding of timing. this is a new engine to me. i just rebuilt a 302 out of my 68 square back mustang from the bare block up. now, finding TDC is no different from an old engine to new. TDC is on the beginning of the power stroke with both valves closed with the exhaust valve opening next in the cycle this is common knowledge.
now from what i read the etched mark in the crank pulley is supposed to be the mark for TDC, as well as the spacers or washers with holes on them or whatever the heck you call em, on the timing gears (with the bigger holes facing eachother) in a horizontal position will be in the same relation to the crank pulley on its timing mark. if this timing mark is not TDC then yes this would make a lot of sense. i was assuming to remove the heads it is always good to put the engine on TDC. but this mark is not and i will upload the pictures of where TDC really is as compared to where this mark on the crank pulley is saying the number 1 cylinder is in relation on this engine

 

[Dowdskees]

this is passenger side timing gear on TRUE TDC not on what the crank pulley says

 

[Dowdskees]

this is driver side timing gear on TRUE TDC