E92 Mileage Change After Low Battery/prolonged stationary period

E9xrob · 08-16-2022, 01:29 AM

Hi all,

I’m looking for some advice and explanation please!

I have a 2007 E92 325i. I bought it with low miles that all seemed legit from the service book, MOT history etc. it did have the tamper light on so I got it checked by a guy with a decent code reader.
His findings were that the CAS module had a different mileage and VIN than the car and DME. Explained the tamper light at least.

It was always a job to do at some point to look closer into the need to get the CAS in virgin state and coded to the car so my tamper light goes.

The car developed a fault and I ended up not using it for a few months and just used the E91 instead. I started and ran the E92 a fair bit and all was fine but then I left it for about 7 weeks without starting or running. I started it the other day and the cluster where the mileage is started at 45xxx as expected and then within a split second flashed off and back on to 125k.

My understanding is that the CAS coding is what is needed so I am hoping someone can help confirm and advise who is best to help?
Also, why would a low battery cause this to happen? I’m confused.

Thanks everyone in advance for any help!

SRLA · 08-16-2022, 04:04 PM

I don't know if this is true with BMW but I vaguely remember hearing of cars where after a hard reset of the electrics (such as the battery going completely flat) on power up the various ECUs will handshake and synch up to whatever the highest mileage is. Is the tamper still on? I would guess your DME has copied the mileage from the CAS.

If this is what happened you're going to have to do the old shady used car salesman trick of rolling the mileage back.

0l0dom0l0 · 08-19-2022, 05:38 AM

I think the mileage is stored in 3 places, CAS, DME and the Kombi.

It is more likely that the ECU was replaced that the CAS module as they are known for water ingress.

Best bet is to speak to Jason at BW chiptune what options you have.

E9xrob · 08-21-2022, 01:47 AM

Thanks for the help both!
I’m pretty sure it was the CAS that had a different VIN and mileage attached when I had it scanned.
I’ll reach out to chip tune, thanks for recommending!

08-16-2022, 01:29 AM	#1
E9xrob Registered 0 Rep 2 Posts Drives: BMW E91, BMW E92, Volvo XC40 Join Date: Aug 2022 Location: Burscough iTrader: (0)	E92 Mileage Change After Low Battery/prolonged stationary period Hi all, I’m looking for some advice and explanation please! I have a 2007 E92 325i. I bought it with low miles that all seemed legit from the service book, MOT history etc. it did have the tamper light on so I got it checked by a guy with a decent code reader. His findings were that the CAS module had a different mileage and VIN than the car and DME. Explained the tamper light at least. It was always a job to do at some point to look closer into the need to get the CAS in virgin state and coded to the car so my tamper light goes. The car developed a fault and I ended up not using it for a few months and just used the E91 instead. I started and ran the E92 a fair bit and all was fine but then I left it for about 7 weeks without starting or running. I started it the other day and the cluster where the mileage is started at 45xxx as expected and then within a split second flashed off and back on to 125k. My understanding is that the CAS coding is what is needed so I am hoping someone can help confirm and advise who is best to help? Also, why would a low battery cause this to happen? I’m confused. Thanks everyone in advance for any help!
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08-16-2022, 04:04 PM	#2
SRLA New Member 6 Rep 21 Posts Drives: e92 335i Join Date: Feb 2022 Location: UK iTrader: (0)	I don't know if this is true with BMW but I vaguely remember hearing of cars where after a hard reset of the electrics (such as the battery going completely flat) on power up the various ECUs will handshake and synch up to whatever the highest mileage is. Is the tamper still on? I would guess your DME has copied the mileage from the CAS. If this is what happened you're going to have to do the old shady used car salesman trick of rolling the mileage back.
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08-19-2022, 05:38 AM	#3
0l0dom0l0 First Lieutenant 69 Rep 316 Posts Drives: BMW E92 330i Join Date: Jun 2020 Location: Uk iTrader: (0)	I think the mileage is stored in 3 places, CAS, DME and the Kombi. It is more likely that the ECU was replaced that the CAS module as they are known for water ingress. Best bet is to speak to Jason at BW chiptune what options you have.
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08-21-2022, 01:47 AM	#4
E9xrob Registered 0 Rep 2 Posts Drives: BMW E91, BMW E92, Volvo XC40 Join Date: Aug 2022 Location: Burscough iTrader: (0)	Thanks for the help both! I’m pretty sure it was the CAS that had a different VIN and mileage attached when I had it scanned. I’ll reach out to chip tune, thanks for recommending!
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