Help with Installing Speedo Calibrater

[poppagar]

I need help. I purchased the Rough Country GM Speedometer Calibrator (17-18 2500 / 3500 Diesel Models) Here: because I needed to recalibrate my speedo because of larger tires. The directions are not very clear. Here: https://www.roughcountry.com/speedometer-calibrator-90005a.html?find=2018-chevy-silverado-2500-hd-4wd-283362

Here is the instruction sheet:

Inline Speedometer Calibration Kit

This installation manual shows an example installation on a 2017 Chevrolet Colorado.  The installation may vary for your vehicle, so it may be necessary to consult a Chevrolet service manual for specific instructions for your year model. Be advised: These instructions may not include specifics for all vehicle configurations. INSTALLATION INSTRUCTIONS

1. Connect the Inline Speedometer Module to your PC with the supplied USB cable and configure it to your vehicle. Once configuration is complete, connect the module to the harness.

2. To remove the Lower Kick Panel, first remove the (2) 7mm screws at the bottom

3. Pull back on the Left and Right side of the Kick Panel at the top to release it. There is one connector for the headlight switch on the left.   *NOTE* The hood release may come loose from the panel, if so, wait until the panel is re attached to install it. It clips in place starting at the front. 

4. Depress tab on headlight switch connector and pull back to disconnect.

5. Look to the left of the steering column and you will see a module with 2 connectors. We will remove the black one by pulling the red locking tab back with a pick, small screwdriver or finger. Depress the tab in the middle and pull backwards to remove.

6. Insert the male portion of the Speedometer Calibrator harness into the female end of the vehicle's harness. Make sure to align the connectors so that the locking tabs are on the same side. Run a zip-tie through the tabs to secure the connectors. 

7. Connect the female end of the Speedometer Calibrator harness into the vehicle's module.

8. Tuck the harness up in front of the module away from harm’s way. 

 9. Start the vehicle and check for any warning signs or messages.

10. Test drive vehicle to ensure proper speedometer function.

 

The fact that the instructions are for a 2017 Chevrolet Colorado don’t really help much either.

 

Anyway, I look under the dash near the steering column and there are 6 different plugs. I don’t know which module I’m supposed to disconnect so I can connect the Speedometer Calibrator harness. I called Rough Country for help but the guy was absolutely no help what so ever.

 

It says it may be necessary to consult a Chevrolet service manual   but I don’t own one.

I can take some pictures of what's under there next to the steering column if it will help.

Can anyone help me find out the correct module to disconnect and reconnect to.

I’m at a complete loss. Any help would be greatly appreciated.

 

 

[jerseytaylor]

I would return that thing ASAP man

I got this: https://superchips.com/shop/gm-flashcal-for-truck and it works very well.

recalibrated my speedo and changed my tpms threshold as well.

the directions, if I recall, are super simple.

plug it into the OBDII under the dash, turn the key to "on" - DONT turn the truck fully on. the device powers on, and you follow the steps on the handhelds screen all the way to the end which is simply hitting ok, letting the handheld work its magic, and then unplugging.

FYI measure your tires with a measuring tape while theyre on the truck to get their most accurate size. 

[poppagar]

Will this work on my 2018 6.6L Duramax L5P? I've not yet found anything that will.

[jerseytaylor]

it should. there was an option to choose either gas or diesel in the drop down. Give them a call before purchasing though. their tuning handheld is different from the one i got that is used primarily for diagnosing, and recalibrating etc.