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Steve
Steve, BMW Expert
Category: UK Car
Satisfied Customers: 23027
Experience:  BMW Expert
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I have a 2004 BMW 645Ci with the error codes P0393 and

Customer Question

Hi I have a 2004 BMW 645Ci with the error codes P0393 and P0024. I have a spare Vanos (I can change these) and have purchased a camshaft sensor as well.
The check engine light is not on, the car does seem like it misfires now and then but revving the engine clears it. I've had this issue for a while now and it's had a couple of oil changes since as well.
The main concern that I have, is that when the car is hot, the car just won't start. The starter motor won't engage at all. There's a click behind the dashboard but nothing from the starter at all! I have to wait 20-30 minutes for the car to cool down before the starter motor will engage again. I have replaced the battery with same spec as factory (had the computer in the car programmed for new batter) and even had the starter motor replaced but still have this issue.
Could my error codes be causing this "won't engage starter when hot" issue?
If so - any tips on how to change the camshaft sensor and which one I have to change?
Submitted: 26 days ago.
Category: UK Car
Expert:  Steve replied 26 days ago.
Hello and welcome,

My name is ***** ***** it will be my pleasure to assist you today.
the answer to your question "Could my error codes be causing this "won't engage starter when hot" issue?" is no, these codes cannot prevent the starter from turning.
Please let me know if you have further questions. Please do not forget to click a positive rating as this is the only way I receive credit for my answer, thank you
Customer: replied 26 days ago.
Can you tell me what could be causing that then? Car starts first time every time, it's just after I have driven the car and when the engine is hot, the starter will not engage.
Expert:  Steve replied 26 days ago.

is the car automatic or manual?

Customer: replied 26 days ago.
It's an automatic.
Expert:  Steve replied 26 days ago.

I would suspect the issue has to do with the transmission failing to send the proper signal that it is in P or N when hot. Also the IVM could potentially be the issue

it could also be an issue with the immobilizer although this is less likely to be temp related.

Please do not forget to click on a positive rating

Customer: replied 26 days ago.
Sorry, should have mentioned. I've already changed the IVM. How do I fix the issue if it's the gearbox not sending the proper signal?
Expert:  Steve replied 26 days ago.

you would need to replace the tansmission position switch.

really the next step should be to replicate the issue with a factory BMW scan tool hooked up to verify the cause.

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Customer: replied 26 days ago.
I have INPA and when I scanned the entire car, the only codes I got were the ones that I have mentioned and the other one was the air quality sensor (I forget what the code is but it's related to the air condition circulation).
Expert:  Steve replied 26 days ago.
you would need to have a trained technician use the factory tester to look at all live data from the car, a fault scan isn't enough.
Please do not forget to click on a positive rating