s4TTq

Hey guys, first time posting on AW, but i've been surfing around for a while.

All of a sudden my car (MY2000) will not start. It will crank and crank, but won't start up. When ignition is in the on position, the EPC and check engine lights do not light up, and I have no communications via VAG-COM with engine module

Battery is good, reading 12V. No blown fuses in the fuse panel.

Checked the harnesses off the ECU, and they look fine, and are not loose.

Pulled of kick panel on driver's side, all terminals have 12V also, and moved to relays.

This was my first time testing relays and jumping terminals, so tell me if i did something wrong, but the I pulled the fuel pump relay, and jumped negative and positive terminals, I heard the fuel pump priming, and a large hissing noise near the fuel pressure regulator. I tried to start the motor, but it just kept cranking and cranking like usual.

Is this relay the same that controls the ECU? Did I test correctly? Where do I go from here?

Thanks for your help guys, I'm at the end of my rope with this.

Rory

How do you know the battery is good? When was it last replaced?

Rory

complacentsee

A reading of 12V on the battery would actually mean its dead. But since it cranks I'm going to assume it was something like 12.4-12.5V measured at the terminals.

Failure of the EPC and check engine light and vag communications should be indicitive of ECU loss of power, or catostrophic ecu failure. (similiar to be it being unplugged) This have the engine crank and crank but never start.

r1de23

id check the ignition control module....

JBear::FATS

The fact that you can't connect via VAG-COM is a concern. Disconnect the positive, batter terminal, disconnect and remove the ECU, wait 10 minutes, re-connect ECU, re-connect the battery terminal and try VAG-COM again.

Maybe someone would be willing to let you try their ECU, if the above does not provide some hope.


I've ran my battery out a few times, car would NOT turn over when the battery was dead, just a click.

JBear::FATS

Verify your fuses also ...

complacentsee

Just to try and clarify. I was trying to say that if the EPC light doesn't light up, the car won't start. But your problem does not sound like it lies in the drive by wire subsystem. The epc control lies within the ecu. Since the check engine light also fails to illuminate while the key is on... this is a pretty good sign that there is a communications failure between the ecu and the instument cluster.

Since both of these issues are happening at the same time, I would seem likly that an issue would be in the ECU or the instument cluster. But the car doesn't start. So, that makes the instument cluster an unlikly source of the issues. Further more, the lack of the communication from the vagcom would likely mean that the ECU does not have power.

You said the car cranks so there is definatly enough charge remaining in the battery to power up the ecu. (side note, just in case, the starter is not controled by the ecu but just the switch) So this leaves it to the the ecu not being supplied power or an internal fault in the ecu, fried circuity what have you.

Now you said you checked the fuses, did you swap a new on in under the ecu location, maybe it is still somehow a bad fuse. A relay supplying power to the ecu.. I thought vagcom could comunicate without the key being in... (I could easily be mistaken)

I would suspect that you have an ECU failure or the ECU is not being delivered power.

r1de23

if the ecu is good.. i would check the basics bro... do you have a spark is the question..

markspoon

Still could be the fuel pump?

complacentsee

No spark will occure without the EPC light being lit prior to cranking.

Fuel pump would not cause this issue. Has to be something in the EPC system or subsystems, or ECU. (or an electrical issue related to them)