Question about GMC Sierra 3500

1 Answer

4l80 e transmission speedo does not go over 48 mph and at 55 mph slips and bangs when it changes gear

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • GMC Master
  • 959 Answers

Sounds like the module is bad... alot of the later model 4L80Es were recalled for updates... check with your local trans shop.

Posted on Nov 16, 2008


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya Mechanic can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US.
click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Transmission slips out of Overdrive

I would suspect you have a defective transmission valve body, but it takes a few tests at repair facility to prove this.

Jun 14, 2012 | 1993 Ford Thunderbird

1 Answer

I have a 2002 grand marquis with 373 gears and the computer has been performance programed. my problem is after putting in the gears it has my speed off by 15 mph when i do 55 mph or less but when i do 55...

Never heard of that one. You can change the speedo gear in the trans attached to your vehicle speed sensor. More teeth slow the speedo down. count the teeth on the one in there and see what the dealer has. about $5 each.

Dec 09, 2010 | 2002 Mercury Grand Marquis

1 Answer

Hello! Gary, I hope you might be able to help me

I just personally went through somewhat of the same problem, but it happened sporadically when ever the car felt like it, and as it turns out, after i replaces the shift control and the lock-out solenoids along with my speed senor on my tranny, the problem was my transmission ECU, which brand new was 1700 dollars, but i went to the junk yard and pulled one for $48. Its located under the carpet on the passenger side, where the passengers feet would be, and it should be the one on the right, the other computer is the Pgm-fi. If you replace this small box, it should fix your problem.

Nov 09, 2009 | 1987 Honda Accord

1 Answer

1997 Chevy P-32 step van (panel van, delivery van) with 4L80-E transmission: Truck drives and shifts properly in gears one through three, but slips as soon as it shifts into fourth. It will not pull at all...

the fourth clutch is burnt probably due to a bad 4th clutch piston seal... if you can get a good trans that cheap then you should just put one in it unless you are familiar with internal trans repairs...

Oct 13, 2009 | 1997 Chevrolet K1500

1 Answer

1992 Chevy Suburban rpms jump at 60+ mph

When the transmission jumps the extra RPM by 200 or 300 RPM. That's your Torque Converter Clutch lock up disengaging or it's slipping. Pull the transmission dip stick out and check the fluid level and condition of the fluid, look to see that it's not burning. If the fluid is not burning then it's the Torque converter clutch unlocking and the Throttle position Sensor may need to be readjusted, or if the transmission is still running off a TV cable. The TV cable may need to be adjusted and or the transmission filter may be dirty and needs to be changed. Take it to a transmission shop and explain to them what the transmission is doing. I'm not sure if your transmission is an 4L80 or a 4L80E. If it's the 4L80E the PCM and ECM control the lock up to your converter. If the PCM detects a problem with the transmission, it drops the transmission fluid pressure to the converter clutch. If it's a 4L80, it's controlled by the TV cable and vacuum lines to the transmission modulator. Regardless they can look in to this when they change the transmission fluid and filter. Recap: Have the Suburban's ECM scanned for any transmission DTC codes. Service the transmission if the fluid is dark in colour and burnt. Adjust any linkage to the transmission that is an issue to it's performance. Good luck and keep me posted, be glad to help.

Mar 15, 2009 | 1992 Chevrolet Suburban

1 Answer

Slipping into first gear when driving past 40 mph

Dodge has a safety feature on there trannys. Its called limp home mode. If the computer detects a problem with the transmission, it will eather put it in 1st or 2nd and not change just to let you get out of the road or home if your near. But when you restart the car i will reset till it detects the problem again. But for as what the problem is it will be hard to say. With computer trannys you can have it hooked up and scanned for error code.

Feb 15, 2009 | 2000 Dodge Stratus

1 Answer

1989 lincoln mark vll automatic transmission

you may have damaged the overdrive gear, a local transmission shop would be your best bet. for good troubleshoting and estimate.

Nov 10, 2008 | 1989 Lincoln Mark VII

1 Answer

Transmission problem

I will be trading in car or fix by dealer . NICO club more helpfull thanks anyway.

Sep 12, 2008 | 2004 Nissan Sentra

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

207 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts


Level 3 Expert

77499 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22306 Answers

Ronny Bennett Sr.
Ronny Bennett Sr.

Level 3 Expert

6927 Answers

Are you a GMC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides