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I've got a 2009 SLT-1 FWD and love the vehicle. I hear a small clunking noise that seems to come from the front left hand side of the vehicle everytime I start it and drive about 100 yards.....almost like something is engaging. Is anyone else experiencing this? If so, what has your dealer said as my dealer seems to be avoiding the issue. Not causing a problem but it is a nuisance and I'm owrried it may manifest into a bigger issue. ??? :help:
 

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Sounds like the much talked about ABS self test. If it is, it is normal. Do a search and you SHOULD find the topic discussed, if the search function is playing nice today.
 

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Welcome and congrats on the 09.. I have not merged your thread but will most likely merge it upon confirmation from other memebers...
This sounds like the same thing that was discussed on 07 and 08 models. It is probably the ABS initialization/check making the noise.
See this thread, there was even an old TSB out on this to see if they could lessen the noise.

http://www.acadiaforum.net/forum/index.php?topic=2575.0
 

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My '08 does the ABS test at 5mph and 20mph. Don't hardly notice it anymore. The 20mph test is definitely more noticable.
 

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xseler said:
My '08 does the ABS test at 5mph and 20mph. Don't hardly notice it anymore. The 20mph test is definitely more noticable.
:ditto: And welcome!
 

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The TSB in the thread bonk linked to only applies to vehicles built prior to November 29, 2007, so it wouldn't apply to any 09s.  I'll look around in SI and see if there's anything for the 09s. 

Its likely still the ABS self-check, but there's not currently a TSB listed to reprogram the BCM to reduce the noise for Acadias built after that date.
 

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I definitely hear the self test at about 18-20 mph.
 

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GeoHawk said:
Here's a description of the ABS system initialization:

Power-Up Self-Test

The electronic brake control module (EBCM) is able to detect many malfunctions whenever the ignition is ON. However, certain failures cannot be detected unless active diagnostic tests are performed on the components. Shorted solenoid coil or motor windings, for example, cannot be detected until the components are commanded ON by the EBCM. Therefore, a power-up self-test is required at the beginning of each ignition cycle to verify correct operation of components before the various control systems can be enabled. The EBCM performs the first phase of the power-up self-test when the ignition is first turned ON. The system relay, solenoids and the ABS pump motor are commanded ON and OFF to verify proper operation and the EBCM verifies the ability to return the system to base braking in the event of a failure. The master cylinder pressure sensor performs a self-test by sending a series of specific voltage signals to the EBCM, each for a predetermined amount of time. This phase of the power-up self-test may be heard by the driver, depending on how soon the engine is cranked and started after turning ON the ignition. The second phase of the power-up self-test begins when the vehicle is driven at a speed greater than 12 km/h (7.5 mph) and the EBCM has not detected any traction control module (TCS)/vehicle stability enhancement system (VSES) related malfunctions thus far. When the brake switch indicates that the brake is not applied and the master cylinder pressure is detected as being low, the EBCM proceeds with the test. The EBCM isolates all of the wheels by closing the 4 isolation valves. Due to the fact that all of the wheels are isolated during the second phase of the test, the test must be aborted if the brake is applied while the test is being performed. Occasionally, the driver may detect this by experiencing a momentary hard pedal.

STICKY, STICKY
 

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From GeoHawk:
Here's a description of the ABS system initialization:

Power-Up Self-Test

The electronic brake control module (EBCM) is able to detect many malfunctions whenever the ignition is ON. However, certain failures cannot be detected unless active diagnostic tests are performed on the components. Shorted solenoid coil or motor windings, for example, cannot be detected until the components are commanded ON by the EBCM. Therefore, a power-up self-test is required at the beginning of each ignition cycle to verify correct operation of components before the various control systems can be enabled. The EBCM performs the first phase of the power-up self-test when the ignition is first turned ON. The system relay, solenoids and the ABS pump motor are commanded ON and OFF to verify proper operation and the EBCM verifies the ability to return the system to base braking in the event of a failure. The master cylinder pressure sensor performs a self-test by sending a series of specific voltage signals to the EBCM, each for a predetermined amount of time. This phase of the power-up self-test may be heard by the driver, depending on how soon the engine is cranked and started after turning ON the ignition. The second phase of the power-up self-test begins when the vehicle is driven at a speed greater than 12 km/h (7.5 mph) and the EBCM has not detected any traction control module (TCS)/vehicle stability enhancement system (VSES) related malfunctions thus far. When the brake switch indicates that the brake is not applied and the master cylinder pressure is detected as being low, the EBCM proceeds with the test. The EBCM isolates all of the wheels by closing the 4 isolation valves. Due to the fact that all of the wheels are isolated during the second phase of the test, the test must be aborted if the brake is applied while the test is being performed. Occasionally, the driver may detect this by experiencing a momentary hard pedal.




I'm quoting Geo so I can split the post from this thread and sticky that part to the problems/TSB section.
 

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Wow, it's all so complicated.
Nice to know all the technology that goes into my beautiful Acadia!
 

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I had to read the ABS paragraph 3 times before I completely understood
 
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