No start after extended dead battery
 

Good day everyone, my 02 3.0 has been parked due to a dead transmission for just over a year. I figured I was just going to part it out or maybe fix it at some point. Of course the battery drained all the way down and now after charging it, swapping the battery and attaching a booster pack to it and trying all 4 keys, it won't start. Thoughts, suggestions?

Were going to need more information. When you try to turn it over, wht is it doing? Is it a crank no start? No crank? Lights on the dash on?

All the lights on the dashboard come on but there is no crank.

Check to see if the starter is getting 12 volts to the solenoid to power up the starter. No 12 volts is the reason why the engine is not cranking over.

Ok. If I don't find 12v, what could be the issue then? I know if I find 12v then I need to replace the starter. The car is at my father in law garage which is about 1.5 hours away so I need to have a well thought out plan when I get there.

If you dont have 12v at the starter, then you will need to check the ignition switch. See if the switch is allowing power to come through to the starter.

The other thing I would do is try another key. If the battery is dead in the key, the EWS system will not recognize the key and will not start. But i am not sure what the parameters are. Meaning will the car just turn on but not crank, or just crank all day long no start.

I have 4 keys and I tried all of them. The 2 diamond shape keys lock and unlock the vehicle as they should. I also have a valet key and a plastic key. All do the same thing. I also tried in park and in neutral. Not even a click or hint that the starter is trying to cycle. Lights do not even dim. I will check the starter solenoid first and then check the ignition switch. Open to any other shortcuts if you have any.

You can also check out the relay to the starter. Kill 2 birds with one stone. You can do a swap if you think its the relay after testing. Just keep it simple.

I would start at the ignition switch and work your way down to the starter. It should only take you a few minutes to diagnose the line.

The only anomaly would be the EWS system, but again you could test the EWS and see if it is triggering the 5v signal.

You can attach a wire to the starter solenoid and touch the other end to the positive jump port in the engine compartment. That will provide the 12 volt power needed to energize the starter.

I had an Audi in which it wouldn't crank. AAA came out and banged on the starter before giving up and towing the car back to my house. Checked the 12 volts wire to the starter and there was no voltage. Connected a wire to the solenoid and touched the other end to the positive terminal of the starter and the engine cranked. Put the key in the ignition and turn it to the run position. Crank the engine again and it started. Discovered that about 1 inch away from the terminal that connected to the solenoid the wire had broken. Splice a new wire to a point that was still good and that fixed the no crank situation.

Just an FYI to clarify this oft thought misconception...EWS does NOT require the battery in the remote key to work. If it did, then the valet and spare key wouldn't work because they don't contain a battery. EWS is self powered through induction. A 125 KHz RF signal is sent from the EWS control module to the Ring Antenna (around the ignition cylinder) which inductively powers the coil inside the key and allows the transponder soldered to the IC board inside the key to communicate back the ISN.

The battery in the remote key is only used to transmit the 315 MHz (or 433 MHz in Europe) radio frequency from the remote to the aerial in the rear right cargo window to initiate FZV/DWA (central locking/anti-theft alarm siren system).

See the WORKSHOP HINT in the lower right gray box below: :)