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Discussion Starter · #1 · (Edited)
I just bought a 2015 volt. When I do a slow speed stop I can hear a single tick from somewhere in the rear, easy to reproduce just starting / stopping. Then only on a right turn or a tight circle I hear a stream of ticking sounds. Again easy to repro if I just do a slow speed circle. Not sure if it's the same sound from both. Car is new to me so I'm not sure how long it's been happening. Any ideas what it might be? My leaf/Tesla don't make any sounds switching from regen to braking. I'm taking it to a wheel shop to look at but looking for any advice if this has happened to other volts.
 

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Discussion Starter · #2 ·
Followup: tire shop didn't find anything wrong with the wheel or brakes. I tried pushing down & up on the back of the car to see if the shocks were making noise but nothing. I feel like the single click I'm hearing is related to the brakes and I noticed it's actually much more noticeable outside the car than inside. I borrowed a code reader which found C12FE-00, ECM ABS Pump Pressure Loss.
 

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Discussion Starter · #3 ·
I just noticed this from the manual. "When propulsion is active and the vehicle begins to drive away, ABS checks itself. A momentary motor or clicking noise might be heard while this test is going on, and it might even be noticed that the brake pedal moves a little. This is normal." This in conjunction with the ABS warning might explain it. I hear the click as the car begins to drive away, and again as I come to a stop. I don't feel anything in the pedal. I tried a quick stop to engage ABS but I'm not sure it worked - I didn't feel the pedal vibrate at all. The click is louder from the outside and might be coming from anywhere. I checked the brake fluid which is very dark but up to the max level. I can't find much on the forum about this C12FE code. I did find this bulletin for the 2015 volt but mine isn't showing the DTC: C012E https://static.nhtsa.gov/odi/tsbs/2015/MC-10115018-9999.pdf
 

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The actual brake pad material could be separated from its metal backing plate. This is a known and very common problem with Gen1 Volts. The tick could be from the brake pad rotating slightly within the caliper and bracket.
 

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Discussion Starter · #6 ·
I'm quite sure now that these two sounds are different so I'm going to start new posts with videos. The click seems to be coming from the ABS pump and is "normal" but in this car I think it's exacerbated by the ABS pump pressure loss.

The sound on the right turn sounds kind of like a spring. I don't think it's related to the brakes as I reproduce it without touching the brakes doing a low speed donut.
 

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Discussion Starter · #7 ·
I fixed them both! The sound while making a turn turned out to be a creaking between the rear axle bushing and chassis. Here's a video of how to fix this for a few bucks:

The single tick sound turned out to be a loose axle nut on the front!
 
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