Do keys go bad? Hard time starting car.

psygnosis · 10-03-2012, 06:53 PM

Can the keys fail? I've been having a hard time getting my car started. I put the key in and everything turns on, but when I turn it, the starter wont go, like the clutch isn't pressed, it takes a few tries but it eventually starts. I even went so far at so replace the starter (80k, it was time anyway) had the battery tested and it's still strong. On a whim I tried the other key and it's been starting fine every time. So is it probably the key, or maybe something in the car? How hard is it to get a new key?

elerner61 · 10-03-2012, 07:05 PM

Why don't you continue to use the other key for a while, just to prove that it's the key. I would particularly see if it always starts on a day when you are in and out of the car often. If it passes that test, then I would think the key (either the key was mechanically worn or something to do with an immobilizer) was the culprit and get a new one.

psygnosis · 10-03-2012, 08:18 PM

Well yea, I'm going to use the other key and make sure that is indeed the issue. I was wondering if this was a common thing.

mhughett · 10-03-2012, 10:22 PM

My son's car wouldn't start and the Indy found out that the chip in the key wasn't communicating with the computer to allow the car to start. Turns out that his key went through the wash in his pants and this probably damaged the chip in the key.

StickMon · 10-04-2012, 12:01 AM

Thanks for the tip and the reminder.
When I bought my car used, it didn't come with a spare key.
If mine goes through the wash or in the pool, I'm toast.

Searching for "spare key" thread ...

bignosejim · 10-04-2012, 12:50 PM

I'm pretty sure that keys have batteries in them, maybe that is starting to die.

psygnosis · 10-05-2012, 01:41 PM

I wouldn't think it'd be the battery. I've had my second key go dead from non-use. It still started the car even when I had to re-pair it to the car to get the remote working again. I did send my 'main' key through the wash once, but that was quite a while ago.

mhughett · 10-05-2012, 04:41 PM

Quote:

Originally Posted by psygnosis

I wouldn't think it'd be the battery. I've had my second key go dead from non-use. It still started the car even when I had to re-pair it to the car to get the remote working again. I did send my 'main' key through the wash once, but that was quite a while ago.

It was several weeks or months after my son's key went though the wash that he started having trouble using it to start his car.

shakemyhand · 10-05-2012, 08:31 PM

Quote:

Originally Posted by StickMon

Thanks for the tip and the reminder.
When I bought my car used, it didn't come with a spare key.
If mine goes through the wash or in the pool, I'm toast.

Searching for "spare key" thread ...

If you take your registration to a BMW Dealership they will make you a new key for $200.00.

Shipkiller · 10-06-2012, 08:45 AM

Key facts:

BMW makes 10 keys for each EWS (immobilizer) module.

If you use all those keys up you will need a new EWS module. (according to BMW)

The dealer does not 'make' you a new key. You provide a valid ID, valid registration with VIN number (both must match) and anywhere from $150.00 to $250.00. The cost is dealer dependent. The dealer then contacts BMW USA and orders a new key based on your VIN.

The battery internal to the key is primarily for the remote locks but is also used as a backup to the EWS power tap. The ignition lock has a circular antenna that 'beams' power to the key and interrogates the internal key transponder allowing the car to start. It also recharges your key battery.

The internal key batteries are not made to be 'user replaceable'. You CAN cut open a key and unsolder a battery and replace it but most will owners do not have this capability to do this.

elerner61 · 10-06-2012, 12:56 PM

Wow, that's a ton of very useful information. What that means to me is that I should periodically swap the key that I use so they both stay charged.

One question, what is the EWS power tap, what does it do, why would it need a backup power source and what good would a backup power source if the powertap's primary power source was dead?

psygnosis · 10-07-2012, 10:00 PM

A dead key battery shouldn't prevent you from starting the car. It's only for the remote.

10-03-2012, 06:53 PM	#1
psygnosis Major 23 Rep 1,034 Posts Drives: '04 Z4 3.0i Sport Join Date: Nov 2008 Location: WA iTrader: (0)	Do keys go bad? Hard time starting car. Can the keys fail? I've been having a hard time getting my car started. I put the key in and everything turns on, but when I turn it, the starter wont go, like the clutch isn't pressed, it takes a few tries but it eventually starts. I even went so far at so replace the starter (80k, it was time anyway) had the battery tested and it's still strong. On a whim I tried the other key and it's been starting fine every time. So is it probably the key, or maybe something in the car? How hard is it to get a new key? __________________ Straightaways are for fast cars, Corners are for fast drivers.
	Appreciate 0 Tweet Quote

10-03-2012, 07:05 PM	#2
elerner61 Major 157 Rep 1,107 Posts Drives: '07 Z4M Roadster Join Date: May 2011 Location: Mount Kisco, NY iTrader: (0)	Why don't you continue to use the other key for a while, just to prove that it's the key. I would particularly see if it always starts on a day when you are in and out of the car often. If it passes that test, then I would think the key (either the key was mechanically worn or something to do with an immobilizer) was the culprit and get a new one.
	Appreciate 0 Quote

10-03-2012, 08:18 PM	#3
psygnosis Major 23 Rep 1,034 Posts Drives: '04 Z4 3.0i Sport Join Date: Nov 2008 Location: WA iTrader: (0)	Well yea, I'm going to use the other key and make sure that is indeed the issue. I was wondering if this was a common thing. __________________ Straightaways are for fast cars, Corners are for fast drivers.
	Appreciate 0 Quote

10-03-2012, 10:22 PM	#4
mhughett Captain 25 Rep 615 Posts Drives: 2007 Z4 M Coupe Join Date: May 2009 Location: Tulsa, Ok iTrader: (0)	My son's car wouldn't start and the Indy found out that the chip in the key wasn't communicating with the computer to allow the car to start. Turns out that his key went through the wash in his pants and this probably damaged the chip in the key. __________________ 2013 Audi TT RS (Tech Pkg, Sport Exhaust, Heated Seats, Sirius) Retired--2007 Z4 M Coupe (Imola Red/Black, Premium Pkg, Heated Seats, XM, Bimmian stubby antenna, CDV delete, Apex EC-7--Anthracite, Goodyear F1 Asymetric 2.
	Appreciate 0 Quote

10-04-2012, 12:01 AM	#5
StickMon My other car is on Mars 636 Rep 3,124 Posts Drives: 2006 MR Join Date: Feb 2011 Location: Lo-Cal iTrader: (1)	Thanks for the tip and the reminder. When I bought my car used, it didn't come with a spare key. If mine goes through the wash or in the pool, I'm toast. Searching for "spare key" thread ...
	Appreciate 0 Quote

10-04-2012, 12:50 PM	#6
bignosejim Lieutenant 40 Rep 400 Posts Drives: 2007 IB M Coupe Join Date: Oct 2011 Location: DFW iTrader: (0)	I'm pretty sure that keys have batteries in them, maybe that is starting to die.
	Appreciate 0 Quote

10-05-2012, 01:41 PM	#7
psygnosis Major 23 Rep 1,034 Posts Drives: '04 Z4 3.0i Sport Join Date: Nov 2008 Location: WA iTrader: (0)	I wouldn't think it'd be the battery. I've had my second key go dead from non-use. It still started the car even when I had to re-pair it to the car to get the remote working again. I did send my 'main' key through the wash once, but that was quite a while ago. __________________ Straightaways are for fast cars, Corners are for fast drivers.
	Appreciate 0 Quote

10-06-2012, 08:45 AM	#10
Shipkiller Colonel 187 Rep 2,138 Posts Drives: Me Join Date: Oct 2007 Location: Virginia Beach iTrader: (3) Garage List 2008 BMW Z4M Coupe [8.50] 2003 BMW Z4 Roadster [8.33]	Key facts: BMW makes 10 keys for each EWS (immobilizer) module. If you use all those keys up you will need a new EWS module. (according to BMW) The dealer does not 'make' you a new key. You provide a valid ID, valid registration with VIN number (both must match) and anywhere from $150.00 to $250.00. The cost is dealer dependent. The dealer then contacts BMW USA and orders a new key based on your VIN. The battery internal to the key is primarily for the remote locks but is also used as a backup to the EWS power tap. The ignition lock has a circular antenna that 'beams' power to the key and interrogates the internal key transponder allowing the car to start. It also recharges your key battery. The internal key batteries are not made to be 'user replaceable'. You CAN cut open a key and unsolder a battery and replace it but most will owners do not have this capability to do this.
	Appreciate 0 Quote

10-06-2012, 12:56 PM	#11
elerner61 Major 157 Rep 1,107 Posts Drives: '07 Z4M Roadster Join Date: May 2011 Location: Mount Kisco, NY iTrader: (0)	Wow, that's a ton of very useful information. What that means to me is that I should periodically swap the key that I use so they both stay charged. One question, what is the EWS power tap, what does it do, why would it need a backup power source and what good would a backup power source if the powertap's primary power source was dead?
	Appreciate 0 Quote

10-07-2012, 10:00 PM	#12
psygnosis Major 23 Rep 1,034 Posts Drives: '04 Z4 3.0i Sport Join Date: Nov 2008 Location: WA iTrader: (0)	A dead key battery shouldn't prevent you from starting the car. It's only for the remote. __________________ Straightaways are for fast cars, Corners are for fast drivers.
	Appreciate 0 Quote