No start 540

[nealf]

Hi all I have an intermittent no start with my 540/6. Shop replaced ignition switch and thought that was the answer. But, it was not. They also jumped the starter which turned the car over. Then they focused on the clutch safety switch and replace that. That worked out for a little while but I went and picked up the car from the shop took it home and once again the car was dead. I turn the key all the lights on the dash light up and nothing happens. When I activated the clutch safety switch by hand I heard what I thought was a relay somewhere under the dash or under the hood that clicked and the car started. Now I do not hear that click. Anything obvious to check?

[JimLev]

What year 540? The electrics changed a little starting in 09/98.
Earlier cars had a started relay behind the glove box, newer cars used the relay in the EWS.
Have you check to make sure the battery posts and clamps are clean and tight?

[nealf]

Sorry the car is a 2000. What’s the EWS? My shop, a non bmw shop is stumped. Where’s this relay located?
Thanks!

[JimLev]

The EWS is the module that reads the key and then tells the DME it's OK to start the engine.
A 2000 doesn't have a dedicated starter relay behind the glove box.
The EWS is on the left side of the steering column, the lower panel need to come off to access it. If the car does start sometimes this probably isn't your problem.
I would find a shop that knows BMW's.

[nealf]

Damn. The battery is new and good and tight. Not sure what to do next. Intermittent issues are hard to tackle. Thanks.

[Chedley]

What is your battery's voltage when the no-start problem occurs ? you can measure it with a multimeter, or read it with OBC.

The majority of intermittent or no-start problems are caused by a low or bad battery or electric connections.

[nealf]

Battery will be tested but seems to be fine. Any other things I should have the shop look out for?

[alberttm]

Why don't you run diagnostics. Check if key is OK. Have you tried a different key?

[nealf]

I tried both master key did not try either of the other two. What is involved in running diagnostics? I apologize for my ignorance. Thank you again

[JimLev]

To run diagnostics you need a computer with INPA or other software on it.

[alberttm]

For now seems like EWS-DME problem, to check this you need to run diagnostics, BMW specific or any multivehicle scanner with BMW support will do...but again make sure all hard components are OK, relays, cables (groundings), accu and etc....

[Bmwe39528i1998]

Intermittent problems are usually connections...
- check ground from engine block to chassis
https://images.app.*******/MwJXgAc113PigRBJ9
Check connections on your starter. There are 3 terminals on it.
If anything is corroded, very likely that's the problem.
I personally don't think it has anything to do with EWS because the problem is intermittent.
Don't assume because the starter turns over when shorted, all is good.
When you short the starter, you provide voltage from starter terminal that always has 12 volts to the starter solenoid.
However when you start the car, it doesn't work the same way.
Start by checking the connections and report back.

[alberttm]

I had a problem with EWS, and it was intermittent. That's why if all mechanical issues are seen, I would recommend to run diagnostics. Actually I always run diagnostics first, so that to make sure the problem is not mechanical, because if the problem is electronic (for instance EWS-DME parity), there is no need to spend time searching for bad groundings, cables etc. you will just need synchronization, but still if the electronic problem occurs frequently, then there is need to search if some mechanical issue causes it.

[Bmwe39528i1998]

What was your EWS issue?
I think the intermittent problem can either be if the connector for EWS is loose or it the relay on it is failing.
I have no idea how EWS connector could be loose given it clips super solid and is tucked away so well that I can't imagine anything pulling on that wire. But I did read of someone fixing the no start issue by saying the wire wasn't plugged all the way.
Now for the relay, it's easy to test.
Get to the EWS box and hold it in hand or touch it as you turn the key to start.
Do you feel a click? If not, then it's probably EWS issue.
Now there's another very simple way to test the EWS.
Unplug the module, short pin 1 and 2 with a fuse and try to start the car.
You're now bypassing the EWS. The car will obviously not start without the module, but it will crank.
If you still have bo crank, EWS is not an issue.


Let us know what you find out.

[alberttm]

My problem was that elmos chip on EWS "went crazy" (probably overheat) so once it would recognize key, another not

[nealf]

I will report back after my findings thanks

[nealf]

Hello all I am reporting back my issue with the no start 540/6. I ended up replacing the EWS ($170.00 from stealer). My non-Bmw shop was able to program the new EWS to my car and two master keys and all WAS well and I picked up the car this week. No issues and car was starting and running great UNTIL yesterday. Went out to dinner last night and parked the car and locked it. My son asked for his football and I gave him the keys to go get it out of the car. He said he hit the unlock button only twice to get it from the back seat. He the relocked the car. My family came out to leave, I put the key in the ignition and NO START AGAIN!!!!????!!! Had to leave the car at the restaurant where it still is now. But this time the car cranks very fast but wont turn over. My original no start issue was nothing when the key was turned except all dash lights on and no cranking.

Could this be related somehow to the EWS and/or my son messing with the key or does this soon like a totally unrelated issue? My wife is ready for me to move on from the car...someone help me so I can keep my car!

New issue is no start but fast cranking.

Thanks again.

[ViolinARC]

You need to get your own code reading software. It makes troubleshooting so much easier than taking it to a shop. The cable and software from B-cables is merely USD$40, which is fraction of what it costs to run the codes at the shop ($180/per)...not to mention your time and energy.

[mattmar1]

cranks over but no start? are fuel pressure and spark present? if theyre both not there, EWS - DME sync becomes suspect. whats the fuel pressure? if youre going to troubleshoot this yourself, a laptop with INPA on it as stated above is needed.

[nealf]

I’m not sure how to get that software. Do I get it online somewhere? Any cables needed or just a laptop?

[Chedley]

About INPA:
1. Google and buy the "INPA k+dcan cable with switch" to connect the laptop to the car.

2. Download "Mike's Easy BMW Tool" freely available software, and install it on any Windows laptop.

Your "crank, no-start" problem seems or could be battery or electric connections related.
I do not think it is the EWS.

[ViolinARC]

cranks over but no start? are fuel pressure and spark present? if theyre both not there, EWS - DME sync becomes suspect. whats the fuel pressure? if youre going to troubleshoot this yourself, a laptop with INPA on it as stated above is needed.

All good questions and advice. Fuel pump or filter could also be suspect...

[nealf]

I know I was thinking fuel pump. It had already been replaced 5 years ago or so. I guess they don’t last forever. I will post results. Thanks again.

[nealf]

Sorry not to post follow up. As it turned out, after replacing the EWS and driving the car for several days, somehow the key I had been using for 13 years became corrupted and I had to start using the other master key. Also the EWS had to be reprogrammed for this spare key and the shop that did all this charged me only like $200.00 for troubleshooting and reprogram. They also wouldn't even let me leave the shop with the old (bad) key.

go figure...