error code 28
Thread Starter
Instructor
Joined: Sep 2004
Posts: 208
Likes: 1
From: Lawrenceville GA
error code 28
Service engine soon comes on 10 minutes into a drive. Shift points are longer, harder than normal with just steady acceleration. Code 28 is tranny related but just wondering what to look at first. I've got all gears just have to left off the gas a bit to change better. Any ideas?
Thanks
Thanks
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
What year is the car?
It matters because the error code numbers changed from year to year. Error code 28 on a '92 is a quad driver fault (usually a shorted wire), so we need to know the year.
It matters because the error code numbers changed from year to year. Error code 28 on a '92 is a quad driver fault (usually a shorted wire), so we need to know the year.
Thread Starter
Instructor
Joined: Sep 2004
Posts: 208
Likes: 1
From: Lawrenceville GA
93 and the code reader stated the tranny thing. FSM gave me the quad driver. I do have the shifting problem though. Can't find a fault with the quad and according to the fsm that wont cause the "service light" to come on. And as u know the light never came on yesterday and was shifting somewhat better. Now I've got a knocking from the lr when brakes are applied. I swear it sounds like a loose pad...maybe need to turn rotors...probably been 10 years.
Thanks for the reply
Thanks for the reply
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Your car is much newer than mine and things changed over the years so my expertise becomes less applicable as the cars get newer. That said...
I believe your car has the 4L60E electronic transmission. There is a transmission controller somewhere (part of the PCM, I believe). Somehow your trans controller is having a problem controlling the trans. It could be the controller itself, wiring problems or dirty or corroded connector pins.
Sometimes these things boil down to a purely mechanical problem, like a stuck valve in the transmission. I advise taking it to a transmission shop and having them look at it. They have the expertise to analyze the symptoms and determine what's wrong.
I have seen that the average transmission shop that rebuilds transmissions for soccer moms' minivans doesn't have the right background for troubleshooting and rebuilding a performance application. I suggest calling TransGo (they don't have online tech support) and asking them for a recommendation for a local trans shop:
http://www.transgo.com/
I believe your car has the 4L60E electronic transmission. There is a transmission controller somewhere (part of the PCM, I believe). Somehow your trans controller is having a problem controlling the trans. It could be the controller itself, wiring problems or dirty or corroded connector pins.
Sometimes these things boil down to a purely mechanical problem, like a stuck valve in the transmission. I advise taking it to a transmission shop and having them look at it. They have the expertise to analyze the symptoms and determine what's wrong.
I have seen that the average transmission shop that rebuilds transmissions for soccer moms' minivans doesn't have the right background for troubleshooting and rebuilding a performance application. I suggest calling TransGo (they don't have online tech support) and asking them for a recommendation for a local trans shop:
http://www.transgo.com/
Last edited by Cliff Harris; Aug 29, 2014 at 11:10 PM.
