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Discussion Starter #1
Blew up my Passat a couple years ago, finally had the engine replaced last year. Had a few issues after engine replacement (ESS I think was glitchy) (MAF and IAT codes). Parked it for the winter since a FWD vehicle is pointless in NW Montana during the winter. Went to run it in the spring. Replaced the MAF and IAT. Checked fluids. Battery dead, jumped it, then charged it fully. Go to start it and I get crank for days (sounds good, fast), but no start. Have been doing alot of investigating myself. Read a million posts and have been running around trying to diagnose. Replaced ESS and CPS. No change. Began doing electrical diagnostics to best of my limited knowledge and ability. I found I was not get power to the fuel pump or spark to the plugs. Began tracing voltages and found power is being sent to fuel pump relay, constant and switched. When I apply good ground (directly from ground location in cabin) to pin 16 (which should have have ground signal normally from ECM) I get 12.4v, relay closes and pump kicks on. When I pull the relay out and probe the pins for the relay I find that when I turn the key to run with the positive probe in either 17 or 19 (30 or 15) with the negative to ground location I get 12.4v, but when I put the negative probe in 16 from the ECM I only get 8.8v. When the key is off I of course get 0v, since the ECM would not be trying to close the relay. Would this indicate a faulty ECM perhaps, a grounding issue? When I probe either 17 or 19 and then take the negative probe all the way to pins 1 or 2 in the big ECM connector (where the ECM gets its ground from) I get 12.4v. So the ECM should be GETTING sufficient ground it's just not SENDING it perhaps? There was a very small amount of corrosion on pin 5 fro the ECM but the ECM looks very clean beyond that. When I was looking into the ignition switch I saw rust on the steering column which led me to believe moisture in the cabin. I found some corrosion on the contacts for the ignition switch and cleaned them really well and put it back together. I know this is alot of random information, but I'm trying to avoid getting needless questions so we can move on to what's next and not what is behind me already. Any helpful thoughts, suggestions before I go out and try to find a spare ECM to plug in? One more thought is that I have Eurodyne Maestro and have no problem flashing the ECM, so it is definitely capable of communicating. I am going to attempt at some point to download VCDS Lite and see if I can use the Eurodyne Powertap cable to communicate with VCDS and pull some codes.
 

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What year and engine is your car? That determines which schematic to look at. Some engines have an ECM power relay, some don't.

If the car has been left alone a while, can you hear the fuel pump run when you first open the driver's door? It should run for a couple of seconds to pressurize the line, first time you open the door only.

The ECMs seldom fail. The "switch to ground" circuit is pretty rugged, so I expect there's some other issue.

You say you've cranked forever. Is that continuously? A bad ESS will cause crank/no start, but the bypass is to crank for about 7 seconds continuously. (The ECM starts firing plugs and injectors after 5 seconds, even without an ESS signal, at least for the DBW cars.)
 

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What year and engine is your car? That determines which schematic to look at. Some engines have an ECM power relay, some don't.

If the car has been left alone a while, can you hear the fuel pump run when you first open the driver's door? It should run for a couple of seconds to pressurize the line, first time you open the door only.

The ECMs seldom fail. The "switch to ground" circuit is pretty rugged, so I expect there's some other issue.

You say you've cranked forever. Is that continuously? A bad ESS will cause crank/no start, but the bypass is to crank for about 7 seconds continuously. (The ECM starts firing plugs and injectors after 5 seconds, even without an ESS signal, at least for the DBW cars.)
There is no connection between the CCM and FP, the fuel pump does not run when you open the door.
It runs for about 1 to 2 seconds when you switch on ignition.
I am not sure about the 5+ seconds cranking, but I am pretty sure it would not work on any 1.8.
 

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Discussion Starter #5
It is a 2003 AWM as stated in the title. Mine has the ECM power relay. The fuel pump doesn’t run at any point. No running when the door is opened initially, nor the ignition turned on, nor when cranking. I have cranked continuously for at least 10-15 seconds at a time with no start.
 

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Check or just replace the ECM power supply relay.
That relay is a common cause of your problem, it powers the coils and part of the ECM.
Also check fuse #29.
 

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Discussion Starter #7
I have checked the relay in the sense that I applied 12v to both sides and the relay closed. I believe I also took the cover off and verified that the relay closed when the key was turned on. I also want to believe that I ent as far as to check something downstream of it to verify 12v but I can do all of this again to make sure.
All of my fuses are in place and good. I visually checked them to begin with, but yesterday I also checked continuity just in case. I’ll check to see if it is receiving power today.
 

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Discussion Starter #8
I checked fuse 29 (and 31 since it looks like it receives its power directly from the ECM power relay) with the key on and both were getting 12.2v. This would mean that the relay is good right?
 

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Nearly any cheap OBDII reader and VCDS Lite will be able to read the codes. I'd try that route before anything else.
 

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The ECM power supply relay shouldn't switch on with the ignition on, until the ECM senses the engine is turning.
 

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Discussion Starter #11
I checked it after work today to verify. I took the cover off of the ECM power supply relay and had my wife turn the ign on. I watched it close. Don’t know what that means if it isn’t supposed to?
 

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I checked fuse 29 (and 31 since it looks like it receives its power directly from the ECM power relay) with the key on and both were getting 12.2v. This would mean that the relay is good right?
No that doesn't mean the relay is good, it just means the coil is getting powered.
I still think it is the most likely cause of your problem, and it is a pretty cheap relay.

It appears that your model doesn't need the engine turning to activate that relay.
The engine does need to be turning for the fuel pump to activate.
(except for about 1 to 2 seconds when the ign is switched on, and it only does that up to 3 times between starts)

Do you have 12V at the coils when the ignition is on ?
 

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Discussion Starter #13
So, finally got to the car again today. Confirmed 12v at coils with ign on. Confirmed 12v to ECM. New development is no comm. with ECM. When this began a month ago I could read the codes, access Eurodyne, etc. Now error message from OBD reader, and failure to communicate with Eurodyne. Thoughts?
 

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What is Eurodyne ?
"Now error message from OBD reader" What error message/s ?
There are a few places where 12V is supplied to the ECM, which did you check ?
 

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Discussion Starter #15
Tune software. It connects through a Powertap cable into the data link port.
It’s a cheap OBD2 reader and it attempts to read, then just comes up with “Error”
 

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I again suggest you replace the ECM power supply relay, it could cause all your problems including the no communication.
It only costs a few dollars and is easy to replace, a pretty cheap way to eliminate a common failure point.
 

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Discussion Starter #18
I ordered one earlier today, I also ordered a used ECM as well since they are decently inexpensive. I also am getting a vag com cable and vcds lite to try to make things easier to track down.
 
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