2004 BMW 5 Series Key Replacement

The 2004–2010 5 Series uses the same key setup, so everything on this page applies to those years too. The full picture is on the BMW 5 Series key guide.

2004 BMW 5 Series: key facts

Key type: Smart / proximity key
Push-to-start: Yes
Transponder chip: ID46 (PCF7945, Hitag2)
Programming: OBD
All keys lost: We can originate new keys on site

Slot-fob car (insert fob in dash slot, press Start; Comfort Access optional). Sources genuinely conflict on which CAS module these years carry: German trade sources say CAS1/CAS2 for early E60s, while a tool-compatibility table lists CAS2 for 2004-2006 and CAS3 for 2007 — so we identify the CAS generation from the module itself (VIN/part number), never from the model year alone. The ID46 key part is the same across 2004-2010; only the procedure changes with the module. Add-a-key and all-keys-lost are documented OBD procedures for E-series CAS modules (e.g., Abrites BN014/BN016); late CAS3+ 'ISTAP' firmware can require a flash downgrade first — specialist, not dealer-only.

What kind of key does a 2004 BMW 5 Series use?

The 2004 5 Series is a slot-fob car. You push the fob into a slot in the dash and press Start. Comfort Access, the hands-free entry option, was available on some cars. Inside the fob is a transponder chip from the ID46 family (PCF7945, Hitag2). That chip is what the car checks before it lets the engine run.

The fob also carries a mechanical backup key. If the fob battery is flat, the backup key still opens the door. It is also the key to keep in mind if you ever have a lock problem, because it works on its own.

For you as the owner, this means a replacement is not a simple cut-and-go job. A blank fob has to be programmed to your car's immobilizer, and the key blade has to be cut to match. We do both.

Is it a duplicate or an all-keys-lost job?

This setup does not need an original key in hand. If you have one working key, we can add another. If you have none, an all-keys-lost job is still possible. Both are documented procedures done through the OBD port under the dash, so the car does not have to go to a dealer for it.

Adding a key when you still have one is usually the easier and more economical route. If you are down to the last fob, make a spare now rather than waiting for it to fail.

One working key: we add a new one through the OBD port.
No working keys: we do an all-keys-lost job through the same port.
Original key not required for either job.
Dealer-only is not the case for this year. Some later-firmware modules need a specialist step first, which we cover below.

What we've usually found behind key trouble on these cars

Not every no-start on a 2004 5 Series means the key is bad. The common problems for this year are worth checking before you pay for a new fob.

A dead or worn-out rechargeable fob battery. The dash slot still reads the fob, so the car usually starts anyway. A fob that only needs a battery or a rebuild does not need replacing.
Electronic steering-lock (ELV) faults. These can look like a key failure, with no start and a key that seems fine.
A worn dash key slot or a cracked fob shell. A cracked shell can often be fixed without a new key.

How we handle it, step by step

We start by working out whether you need a new key at all, then match the job to your car.

You call (213) 577-1366. We answer 24 hours a day, 7 days a week.
We ask for your VIN and what keys you have, including the mechanical backup key.
We check the fob and the dash slot, and rule out a battery or steering-lock issue.
We identify the module and its software from the car itself.
We cut the key and program the ID46 transponder through the OBD port.
We test the key in the slot, at the door, and with the backup blade before we leave.

Locked out or need a locksmith now?

We answer around the clock, every day of the year.

Call (213) 577-1366

What affects the price?

We don't quote numbers on a web page, because the real cost depends on your car. These are the factors that move it:

Whether you are adding a key or doing all keys lost. Adding is usually the lighter-cost job.
The module generation and its firmware. A late firmware version may need extra work before programming.
Whether the problem is the key at all. A battery, shell or ELV fault is a different repair than a new key.
How many keys you want made, and whether you need a mechanical backup blade cut.
Whether the car is at our Westwood storefront or we come to you with a mobile van.

What we confirm by VIN, not by year

Here is one thing we say plainly: sources disagree on which CAS immobilizer module these years carry. German trade sources point to CAS1 or CAS2 on early E60s. A tool-compatibility table lists CAS2 for 2004 to 2006 and CAS3 for 2007. So we do not decide from the model year alone. We identify the CAS generation from the module itself, using the VIN and part number.

The ID46 key part is the same across 2004 to 2010. What changes is the procedure, depending on the module. Some later CAS3-type firmware, known as ISTAP, can need a flash downgrade before a key can be added. That is specialist work, but it is not dealer-only. We'll tell you if your car falls into that group before we start.

Why call Wilshire Lock & Key

We have been in business since 1987, with a storefront at 10740 Wilshire Blvd in Westwood and mobile vans that serve 140 cities across Los Angeles and Ventura counties. You deal with one company, not a dispatch middleman. David, the owner and lead technician, oversees the work.

California requires locksmith companies to hold a BSIS LCO license, and you should ask any locksmith for it before work starts. For more on your car, see our BMW key pages and the 5 Series overview, or contact us directly.

Frequently asked questions

Can you make a 2004 BMW 5 Series key if I've lost every key?

Yes. All-keys-lost is a documented OBD procedure for these modules, and no original key is needed. We confirm the module from your VIN first.

Do I need the original key to make a copy?

No. For this setup the original key is not required to add a new one.

Does my car use a transponder chip?

Yes. The fob carries an ID46 chip (PCF7945, Hitag2), and it has to be programmed to your car's immobilizer.

My car starts but the fob seems weak. Do I need a new key?

Maybe not. A dead or worn rechargeable fob battery is a common problem, and the dash slot can still read the fob so the car starts. We check that first.

Is this a dealer-only job?

No. Add-a-key and all-keys-lost are specialist OBD procedures we can do. Some later-firmware modules need a flash downgrade first, but that is still specialist work.

Why do you ask for my VIN instead of just the year?

Sources conflict on which CAS module these years use. We identify it from the VIN and part number rather than the model year.

Can I use the mechanical key if the fob battery dies?

Yes. The backup key opens the door on its own. Starting the car still needs a fob that the car can read.

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Reviewed by David, Owner & Lead Technician, Wilshire Lock & Key — in the locksmith trade since 1987.

Last updated 2026-10-11.