Need help -- w12 suddenly won't crank
07-10-2018, 01:35 PM
#11
AudiWorld Super User
My car does click once in a while without turning with both key and start button only, but turn off and start again it works right away. I thought it's been a gremlin with A8. May be my time is near, but it's been doing that for many years, especially with my old battery.
Cheers,
Louis
Cheers,
Louis
07-10-2018, 01:39 PM
#12
AudiWorld Super User
My car does click once in a while without turning with both key and start button only, but turn off and start again it works right away. I thought it's been a gremlin with A8. May be my time is near, but it's been doing that for many years, especially with my old battery.
Cheers,
Louis
Cheers,
Louis
07-10-2018, 01:39 PM
#13
AudiWorld Super User
my brake lights work and there isn't a code for that switch, but I will check it again. Is there a way to bypass this and activate the starter manually? I did replace the brake light switch just a couple of months ago due to it causing an esp light but anything is possible.
07-10-2018, 01:42 PM
#14
AudiWorld Super User
Also search BTW on the engine crank sensor. One of the only other things that can fail with no codes, and it is literally the master reference sensor in the whole set up. Some get codes, some don't. I thought it prevented ignition but didn't affect cranking, but don't recall and haven't had it fail personally.
For other stopped cold ideas, also try pulling battery cable for 30-60 minutes. Older D3's get weird electrical storms, usually when battery on way out. I know you said it was good, but when faced with horrific jobs like starter pull, you want to double check all the other ones that folks have seen in actual use. Also, check to be sure your crash sensor fuse isn't blown. That big clunky thing that holds the battery down (IIRC) has a small explosive charge that blows out when triggered by crash sensors. Some systems stay up (like lighting), while others get cut. The small leads are the trigger (no touch...), while it should show continuity across the main cable bolt ups with an ohmmeter if not blown.
For other stopped cold ideas, also try pulling battery cable for 30-60 minutes. Older D3's get weird electrical storms, usually when battery on way out. I know you said it was good, but when faced with horrific jobs like starter pull, you want to double check all the other ones that folks have seen in actual use. Also, check to be sure your crash sensor fuse isn't blown. That big clunky thing that holds the battery down (IIRC) has a small explosive charge that blows out when triggered by crash sensors. Some systems stay up (like lighting), while others get cut. The small leads are the trigger (no touch...), while it should show continuity across the main cable bolt ups with an ohmmeter if not blown.
Last edited by MP4.2+6.0; 07-10-2018 at 01:55 PM.
07-10-2018, 02:02 PM
#15
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Also search BTW on the engine crank sensor. One of the only other things that can fail with no codes, and it is literally the master reference sensor in the whole set up. Some get codes, some don't. I thought it prevented ignition but didn't affect cranking, but don't recall and haven't had it fail personally.
For other stopped cold ideas, also try pulling battery cable for 30-60 minutes. Older D3's get weird electrical storms, usually when battery on way out. I know you said it was good, but when faced with horrific jobs like starter pull, you want to double check all the other ones that folks have seen in actual use. Also, check to be sure your crash sensor fuse isn't blown. That big clunky thing that holds the battery down (IIRC) has a small explosive charge that blows out when triggered by crash sensors. Some systems stay up (like lighting), while others get cut. The small leads are the trigger (no touch...), while it should show continuity across the main cable bolt ups with an ohmmeter if not blown.
For other stopped cold ideas, also try pulling battery cable for 30-60 minutes. Older D3's get weird electrical storms, usually when battery on way out. I know you said it was good, but when faced with horrific jobs like starter pull, you want to double check all the other ones that folks have seen in actual use. Also, check to be sure your crash sensor fuse isn't blown. That big clunky thing that holds the battery down (IIRC) has a small explosive charge that blows out when triggered by crash sensors. Some systems stay up (like lighting), while others get cut. The small leads are the trigger (no touch...), while it should show continuity across the main cable bolt ups with an ohmmeter if not blown.
07-10-2018, 02:14 PM
#16
AudiWorld Super User
i replaced both starter relays and no change. Rhe black box by my battery has been unbolted and getting slapped around for a while now, how do I check if the crash sensor has blown? I opened that black box and there is battery power going to the output side. I checked it against ground
07-10-2018, 02:17 PM
#17
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07-10-2018, 02:44 PM
#18
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I can see the starter it looks fine, I can not feel it click when I turn the key to start so I assume it is not getting power. If it were a bad motor it woukd try to engage and click or something. Isnt there a box between the battery and starter? My d2 did this once and it turned out to be a corroded wire in that box. Where is this on a d3?
07-10-2018, 07:04 PM
#19
AudiWorld Super User
Have you done the 30-60 min. suggested battery disconnect? And again, new battery or not, what are voltage readings you are seeing in the scan in various places? Anything much under 12V is suspect, and by 10V you could be in the no start scenario. Not really the way to measure battery capacity, but my practical experience of the healthy and unhealthy voltages I have seen in my scans over the years.
As another basic one that may be overlooked, are you trying to start it with the console push button? Have you put the key into the ignition slot and tried that way? Thus, could be defective push button switch. Or, power management system which does eventually cut keyless start if it sees power issues. Key slot works all the way until battery is so dead key gets stuck in it. Also, have you tried another key in case key is fried--if you still have two? Sorry if elementary, but don't want to just assume the usual checklist stuff has in fact been run through.
As another basic one that may be overlooked, are you trying to start it with the console push button? Have you put the key into the ignition slot and tried that way? Thus, could be defective push button switch. Or, power management system which does eventually cut keyless start if it sees power issues. Key slot works all the way until battery is so dead key gets stuck in it. Also, have you tried another key in case key is fried--if you still have two? Sorry if elementary, but don't want to just assume the usual checklist stuff has in fact been run through.
Last edited by MP4.2+6.0; 07-10-2018 at 07:08 PM.
07-10-2018, 07:09 PM
#20
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Have you done the 30-60 min. suggested battery disconnect? And again, new battery or not, what are voltage readings you are seeing in the scan in various places? Anything much under 12V is suspect, and by 10V you could be in the no start scenario. Not really the way to measure battery capacity, but my practical experience of the healthy and unhealthy voltages I have seen in my scans over the years.
As another basic one that may be overlooked, are you trying to start it with the console push button? Have you put the key into the ignition slot and tried that way? Thus, could be defective push button switch. Or, power management system which does eventually cut keyless start if it sees power issues. Key slot works all the way until battery is so dead key gets stuck in it. Also, have you tried another key in case key is fried--if you still have two?
As another basic one that may be overlooked, are you trying to start it with the console push button? Have you put the key into the ignition slot and tried that way? Thus, could be defective push button switch. Or, power management system which does eventually cut keyless start if it sees power issues. Key slot works all the way until battery is so dead key gets stuck in it. Also, have you tried another key in case key is fried--if you still have two?