Page 1 of 1
2008 Pontiac Grand Prix - Code 128 Fixed
Posted: Wed Feb 10, 2010 9:13 am
by wfo44
have code 128 ran test and passed , cleared code and returned 2 days later, any info would be great
Re: 2008 Pontiac Grand Prix - Code 128
Posted: Wed Feb 10, 2010 12:28 pm
by VCAC239
A PO128 should be an "insufficient Temp" code. Perhaps it's an intermittent T-stat issue. I would remove & replace with an OEM T-stat & see what you have after that.
Jeremy
Re: 2008 Pontiac Grand Prix - Code 128
Posted: Wed Feb 10, 2010 12:43 pm
by timjlive
I would agree. Every P0128 I have encountered, ended up being the thermostat. Not that you should shortcut the diagnostic process but that's what I have run into. I would just verify the CTS reading with a temp gun to make sure the CTS is accurate. If that's good, it gets a stat.
Re: 2008 Pontiac Grand Prix - Code 128
Posted: Thu Feb 11, 2010 3:21 am
by steven kiser
i've been running into sensor issue a bit on gm's lately. like stated above check cts reading for the pcm through scanner.
Re: 2008 Pontiac Grand Prix - Code 128 fixed
Posted: Fri Feb 12, 2010 6:25 am
by wfo44
checked against temp gun and cts pulled t stat stuck open thanks yall