Speedometer correction
Printed From: the12volt.com
Forum Name: Vehicle Wiring Information & File Requests
Forum Discription: Request Car Alarm, Car Stereo, Cruise Control, Remote Starter, Navigation, Mobile Video, and Other Vehicle Specific Wiring Info, Manuals, Tech Tips
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=139669
Printed Date: May 02, 2024 at 8:38 AM
Topic: Speedometer correction
Posted By: rjr50
Subject: Speedometer correction
Date Posted: November 05, 2015 at 12:09 AM
I have a 2010 Ram 1500 and I want to install a speedometer correction module which needs to intercept the signal before it reaches the cluster. Can you tell me which wire and best location to make the connection?
Replies:
Posted By: i am an idiot
Date Posted: November 05, 2015 at 10:04 PM
Look for this color wire on the harness going into the cluster. If there is a wire of this color, use a volt meter to verify that the voltage increases with speed. You need to try the meter on AC volts and then on DC volts. If it is the right wire it will increase with speed on one of the 2 settings on the meter.
Speed Sense DARK GREEN/ BROWN (AC) AT PCM MODULE UNDER HOOD ON PASSENGER SIDE 32
Posted By: rjr50
Date Posted: November 08, 2015 at 8:20 PM
Thanks for the reply. I'll check it out and post my findings
Posted By: rjr50
Date Posted: November 08, 2015 at 9:18 PM
Just looked at the wiring diagram and it shows the Dark GREEN/ Brown wire connects the transmission output speed sensor to the PCM. I had originally thought I could use the signal coming from that sensor but when I disconnected the sensor at the transmission and drove the vehicle the speedometer was still working so I assume the speedometer gets it's signal from somewhere else. Any thoughts on this?
Posted By: Ween
Date Posted: November 08, 2015 at 10:02 PM
The speedometer/instrument cluster receives information via CAN bus. There isn't a direct wired input to the speedometer. Did you change tire sizes or differential gears? The dealer can probably reprogram the PCM, or maybe a Hypertech speedometer calibrator?
Posted By: rjr50
Date Posted: November 09, 2015 at 8:58 AM
Thanks Ween, that's what I've been suspecting would be the answer but the people I bought the module from insist that it should work even though they are also having trouble identifying the connection point.The module I have is the Yellow Box from Yellr.com.
Posted By: Phreak480
Date Posted: November 10, 2015 at 7:48 PM
Ween] wrote:
The speedometer/instrument cluster receives information via CAN bus. There isn't a direct wired input to the speedometer. Did you change tire sizes or differential gears? The dealer can probably reprogram the PCM, or maybe a Hypertech speedometer calibrator?
I'd just get the computer reprogrammed for the tire size. I did it on my 03. No rewiring to do, and easily reversible.
Posted By: arlind86
Date Posted: November 11, 2015 at 1:17 PM
There is a speedsensor on one of the wheels.
The speed sensor in the transmission is not the sensor you're looking for.
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