"Clunk" caused by VDC Diagnostic at Start-Up

resopaton · 08-20-2010, 05:08 AM

So I was doing some homework on the VDC system and came across something in the Owner's Manual I found interesting.

In section 5-27 it says:

The VDC system computer has a built-in diagnostic feature that tests the system each time you start the engine and move the vehicle at low speed forward or backward. When the self-test occurs, you may hear a "clunk" noise and/or feel a pulsation in the brake pedal. This is normal and is not an indication of a malfunction.

Has anyone else heard or wondered what the "clunk" was?

daisuke149 · 08-20-2010, 06:22 AM

Everytime i drive off i heard something. Never knew what it was. Happened in my gto also.

nogoodname · 08-20-2010, 07:07 AM

This also happens in my G35 but I thought it was the abs system.

370Zsteve · 08-20-2010, 07:10 AM

I only hear (and feel) a clunk on clutch engagement in 1st gear.........

CBRich · 08-20-2010, 08:04 AM

Not sure about VDC but as stated before I know ABS systems often do this.

JvKintheUSA · 08-20-2010, 07:38 PM

There are a ton of posts about the clunk. It is not the VDC IMO, but rather play in the drive train. It is a metal on metal sound and I had it fixed a year ago, but came back recently.

sonic370 · 08-20-2010, 09:32 PM

That's not it drive train i think. i had an 05 and know a 09 both AT
every time i went from park to reverse i would hear a slight click.
of course nissan said it was normal.

shadow2k · 08-21-2010, 01:13 AM

I turn off VDC. I have no clunk. I do get the clunk when I have VDC on.

Anyone who doesn't believe it is VDC, feel free to test it out yourself. My clunk doesn't exist, because my VDC is always turned off at startup.

08-20-2010, 05:08 AM	#1 (permalink)
resopaton Base Member Join Date: Oct 2009 Location: Joplin, MO Posts: 84 Drives: 13 PW Nismo Rep Power: 16	"Clunk" caused by VDC Diagnostic at Start-Up So I was doing some homework on the VDC system and came across something in the Owner's Manual I found interesting. In section 5-27 it says: The VDC system computer has a built-in diagnostic feature that tests the system each time you start the engine and move the vehicle at low speed forward or backward. When the self-test occurs, you may hear a "clunk" noise and/or feel a pulsation in the brake pedal. This is normal and is not an indication of a malfunction. Has anyone else heard or wondered what the "clunk" was?

08-20-2010, 07:10 AM	#4 (permalink)
370Zsteve A True Z Fanatic Join Date: Sep 2009 Location: Gold Coast CT Posts: 10,599 Drives: 2019 Corvette G.S. Rep Power: 43	I only hear (and feel) a clunk on clutch engagement in 1st gear......... __________________ SOLD MY Z MARCH 2018 - another Core OG moves on - new ride 2019 Z Corvette Grand Sport - no mods necessary but already have eyes on HFC and intakes LOL IT NEVER ENDS.

08-20-2010, 07:38 PM	#6 (permalink)
JvKintheUSA Enthusiast Member Join Date: Jun 2009 Location: Canton, GA Posts: 465 Drives: 2013 Shelby GT500 Rep Power: 428	There are a ton of posts about the clunk. It is not the VDC IMO, but rather play in the drive train. It is a metal on metal sound and I had it fixed a year ago, but came back recently. __________________

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08-20-2010, 06:22 AM	#2 (permalink)
daisuke149 My *** is famous! Join Date: Mar 2010 Location: Alpharetta, GA Posts: 4,849 Drives: 2013 Boss 302 PW Rep Power: 31	Everytime i drive off i heard something. Never knew what it was. Happened in my gto also.

08-20-2010, 07:07 AM	#3 (permalink)
nogoodname Lifetime Premium Join Date: Nov 2008 Location: Montreal Posts: 22,357 Drives: E46 M3 Rep Power: 1765	This also happens in my G35 but I thought it was the abs system.

08-20-2010, 08:04 AM	#5 (permalink)
CBRich A True Z Fanatic Join Date: Apr 2009 Location: SC Posts: 2,464 Drives: 370Z Rep Power: 544	Not sure about VDC but as stated before I know ABS systems often do this.

08-20-2010, 09:32 PM	#7 (permalink)
sonic370 A True Z Fanatic Join Date: May 2010 Location: Orange Texas Posts: 1,574 Drives: 09 370Z Sports PGK Rep Power: 18	That's not it drive train i think. i had an 05 and know a 09 both AT every time i went from park to reverse i would hear a slight click. of course nissan said it was normal.

08-21-2010, 01:13 AM	#8 (permalink)
shadow2k Base Member Join Date: Jul 2009 Location: Overland Park, Kansas Posts: 143 Drives: 09 PG 370z 6MT Rep Power: 16	I turn off VDC. I have no clunk. I do get the clunk when I have VDC on. Anyone who doesn't believe it is VDC, feel free to test it out yourself. My clunk doesn't exist, because my VDC is always turned off at startup.