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Discussion Starter #1
Hi all,

I've been having an issue with my car where the airbag light is on and the radio refuses to power on. There are no other symptoms beyond those two. I've checked all the fuses and have no casualties in both the glove box box or the rear trunk box.

After doing some googling the last few weeks I went ahead and replaced the ignition switch as apparently that is a common issue. New switch is in and the car runs just fine, but those two issues persist.

Any thoughts? I'd love to have my music again.. :sad3:
 

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Discussion Starter #2
Nobody? I have BMW scanner 1.4 and took a look through it, unfortunately I'm not too hot on programming and can't see anything wrong off the bat... Is there another module that can impact both the radio and the airbag?
 

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For your radio issue, does the display work? Have you checked the fuse in the radio module?
 

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Discussion Starter #4
For your radio issue, does the display work? Have you checked the fuse in the radio module?
Display works perfectly, just no audio and when I depress the 'power' knob on the left nothing happens.

Where would the fuse inside the radio be located? Dash?
 

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Display works perfectly, just no audio and when I depress the 'power' knob on the left nothing happens.

Where would the fuse inside the radio be located? Dash?
The radio's fuse in in the back (top) of the radio module with the black electrical connector. IIRC, for the c43 it is a 7.5A. While you have the radio module out, check for signs of water intrusion and corrosion in the terminals. Water intrusion is a common issues which can cause radio failure (catastrophic or otherwise) due to leaking at the left tail light gasket.
 

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Discussion Starter #6
The radio's fuse in in the back (top) of the radio module with the black electrical connector. IIRC, for the c43 it is a 7.5A. While you have the radio module out, check for signs of water intrusion and corrosion in the terminals. Water intrusion is a common issues which can cause radio failure (catastrophic or otherwise) due to leaking at the left tail light gasket.
Highly interesting, thank you. I believe this first occurred shortly after changing to the LCI tail lights and it was raining heavily... I shall report back with findings.
 

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I've been having an issue with my car where the airbag light is on :sad3:
Attach an airbag scanner and get the codes. A specific code is set along with the light display. This is NOT the same as OBDC codes....
 

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C43 Radio Connector


BM53/4 Radio Connector
 

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Discussion Starter #9 (Edited)
Thanks guys. The fuse is still fine and there was only a minor amount of corrosion on the connector, which I cleaned up. Could that have killed the radio? If it was the water in the trunk, would that affect the airbag system somehow? Both issues presented at the same time.
 

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I don't recall any components of the air bag system in the boot but there is a ground connection near the radio (IIRC it is by the taillight).

But as the likely suspects for the radio are confirmed as being good, how is the battery; as these cars are notorious for acting very strange when the battery is under performing.

As Ard has recommended it is also time to get the airbag system scanned for specific faults and also the radio. INPA, DIS, and even Navcoder can do this. If you do not have any of these try a shout out to the plethora of Chi-town members. One of them may be willing to lend a local hand or you favorite Indy or dealer. If you need or would like I have my old c43 radio that I can lend for diagnostic purposes.
 

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Discussion Starter #11
I don't recall any components of the air bag system in the boot but there is a ground connection near the radio (IIRC it is by the taillight).

But as the likely suspects for the radio are confirmed as being good, how is the battery; as these cars are notorious for acting very strange when the battery is under performing.

As Ard has recommended it is also time to get the airbag system scanned for specific faults and also the radio. INPA, DIS, and even Navcoder can do this. If you do not have any of these try a shout out to the plethora of Chi-town members. One of them may be willing to lend a local hand or you favorite Indy or dealer. If you need or would like I have my old c43 radio that I can lend for diagnostic purposes.
Battery seems fine. I usually go 2 weeks without driving the car, but it starts up instantly every time and I've never noticed any issues that would warn me of a weak battery..

As for tools, I have BMWscan 1.4 and the Evolve tuner, that's it. I apologize for my relative ignorance with the different diagnostic applications. yawnnnn

Appreciate the offer for a radio loan. I'd like to see if there's any other simple things I can try before swapping hardware around. I have a bad feeling dealing with shipping a radio back and forth and with my luck that won't be the issue.. Especially with the additional airbag code.

Attach an airbag scanner and get the codes. A specific code is set along with the light display. This is NOT the same as OBDC codes....
Do you have a recommended (read: inexpensive) model?
 

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Take a look at "Test-09" on the OBC. If the voltage is low (>13.4v at idle) try putting the battery on a tender for the night; re-test, if the voltage is still low it may be time for a battery or regulator. If the voltage is normal either directly or after a slow charge, and the issues persist, the battery can likely be ruled out. PA Soft's BMW Scanner should work for interrogating the individual modules.

There are two buttons on the M5's instrument panel. The button to the lower
left of the speedometer is the reset button for the trip odometer, which I'll call
the Reset or R button. The button to the lower right of the tachometer is the
check control key, which I'll call the Check or C button. If you don't have both
of these buttons—and the check control indicator—on your instrument panel,
this isn't likely to work for you.
1. The first step is to turn the key to position 1 or 2 without staring the
engine.
2. Fasten the seat belt to get rid of the "Fasten Seat Belt" message.
3. Press the right button on the instrument panel, and hold it until "TESTNR.
01" comes up (5 to 10 seconds).
4. Press the left button on the instrument panel, and the
Vehicle

Identification​
Number comes up (last 7 digits of VIN).

5. Add up the last 5 digits to get the "unlock code", e.g. the unlock code for​
"AB12345" would be 15 (1+2+3+4+5).​
6. Repeatedly press the right button until "TEST-NR. 19" appears.​
7. Press left button -> "LOCK : ON”​
8. Repeatedly press left button until "LOCK : xx" appears, where "xx" is​
your unlock code.​
9. Press the right button.​
All modes are unlocked now.Now hold in the Check button. The check control​
indicator will read "​
CHECK CONTROL OK". Keep holding the button. After a

few seconds the indicator will go blank, and after a few seconds more the​
indicator will display "
TEST-NR. 01". Now release the Check button.

TEST-NR. 09
VB: xx.x V
(battery voltage)

Tests 08 and 09 have just one display each, and both are somewhat useful. My
battery voltage, idling in the garage, was around 13.5 V.

View attachment e39-m5-secret-menu.pdf
 

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Discussion Starter #13
While idling the battery voltage reads:
UB: 13.5V-13.7V

While off the battery voltage reads:
UB: 12.4V
 
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