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SPEEDOMETER ISSUE Does not go back to 0, reads incorrect speed

20streetrod06

20streetrod06

Full Member
Joined
Oct 7, 2020
Messages
281
Location
Central IL
so today on my way to work cruising along like normal, it just "felt" slower. so I came to a complete stop and sure enough at a full stop my truck speedometer shows 20mph. I opened up a GPS app on my phone and it verified that at cruising speed on the speedometer, the actual speed is 20mph less.

I had the gauge cluster re-built in the summer of 2021, and have had no issues since. I'm not even sure where to start on trying to diagnose this one. Has this happened to anyone else?
 
Last edited by a moderator:
Have you tried to see what speed the live data on a capable scanner reads?

If that reads what your GPS is saying, my guess is the cluster is failing.

It is not unheard of for more than one cluster failing.

When I pulled the cluster the first time in my EXT to install a replacement one I had purchased to address a problem it was having, I discovered the cluster in my EXT had previously been replaced due to a factory recall many years previous.

There was a sticker on the back of that cluster indicating it had been refurbished.
 
Just unplug the cluster if it stays at 20 mph it's a bad stepper motor again.
 
Yes it should, if you are brave just disconnect the battery wait a minute and reconnect.
But first turn off the HVAC and close the sunroof if you have one.
 
from a quick look it sounds like the cluster is on the IPC/DIC fuse, I was planning on just pulling it to see if the needle dropped.

I'm curious why you say id have to be brave to disconnect the battery, and why the HVAC and sunroof would need to be closed? what are the risks there?
 
The HVAC and sunroof will not always resync to the proper positions if the battery is disconnected.

Best practice is to turn everything about the HVAC off and have the sunroof closed so that when battery power is reconnected, both items will resync to the proper positions.

The most common problem is the HVAC does not resync properly and you get hot air on the driver's side while getting cold air on the passenger side during AC operation.

These two items are going to resync.

Best to leave them in a best position for success before disconnecting the battery.

After you reconnect the battery, slowly run every HVAC control through to each extreme and cycle the sunroof to all extremes.
 
20streetrod06 said:
ATTN MOD... the title of this thread got changed inadvertently I think...
Click to expand...
changed to something I felt fit.
Let me know if it does not work for you
 
MS03 2500 said:
Pulling that fuse will work also.
Click to expand...
pulled the fuse for a couple minutes and the needle stayed at 22mph. re-inserted the fuse, and after I started the engine, the needle dropped to zero. it was correct the whole way home, and back to work this morning. maybe a one time fluke? maybe a stepper motor starting to fail? for now I'll just be keeping an eye on it.

thank you guys for the knowledge.
 
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