Your 1997 GMC Sierra Speedometer can have problems like speedo not working with ABS light on, Speedo showing fluctuating readings, Speedometer showing high RPM or speed than actual or Speedo needle fixed at zero. These problems can be due to damaged wires, burned fuse, damaged speedometer, trouble code, faulty speed sensor, and speedo calibrated for wrong size of tires.
Riding the 97 GMC Sierra is a true class but one that shows the wrong MPH in the speedo is risky. As driver will not be able to determine the actual speed of the car. In that case, troubleshooting is needed based on the causes.
Here are the main reasons why the 1997 GMC Sierra speedometer problems showing in your car:
- Vehicle Wheel Sensor VSS wire loose or fault in the sensor
- Incorrect size tires are added to the car
- Trouble codes
- The speedo fuse is fried up
After learning the causes, it’s time to solve the bugs that your car’s speedo is suffering from. Let Me Show You!
Fix 1997 GMC Sierra Speedometer Problems
Depending on the error type, I’ll explain the reasons and then give the solutions so you can perfectly solve the bug without making mistake.
1. Speedo Stops Working & ABS Light Turns On
This type of error occur when there is a faulty speed sensor. When speed sensor fails to take read or cannot take proper reading then this can make your ECU or ECM to turn on the ABS light on and will make your speedo stop working.
Steps to fix Speedo That is not working with ABS Light ON
- Wear your goggle and eyewear to ensure safety
- Open the hood of your car.
- Disconnect the negative side of the battery and then the positive side.
- Locate the VSS unit. It is located on the tail shaft housing transmission in 2WD or the transfer case (underneath) in 4WD (on the passenger side).
- Inspect the wiring first and tighten out the plug. If it’s okay, then go to the next step.
- Take an adjustable wrench to loosen the speed sensor
- Use your hand to simply twist the unit and remove it. Do not use a harsh tool as it can break the speed sensor.
- Clean the surface of the sensor and make sure not to clean it with abrasive cloth or apply any impact force on it.
- If this electrical inspection and cleaning does not work then you may need to replace the sensor.
- Insert new VSS that seems good in condition and quality. Be sure to twist it in order to attach it properly. Then, use an adjustable wrench to tighten it out.
- Put on the plug into the port and be sure it’s nicely inserted.
2. Unpredictable Swings of Speedometer
A lot of times the speedo can show inconsistent swings where the indicator needle just goes upward to downward or vice versa. This occurs when you insert the wrong size tire into your 97 Sierra GMC which causes the speedo to read incorrectly.
Steps to fix unpredictable swing of 1997 GMC speedometer
- Check the door jamb to learn about the correct tire size for each tire.
- Remove your car tires and insert new ones.
- Grab a calibrator tool for speedo and simply calibrate it.
No matter which vehicle you have or which car model you drive, you can easily found about the recommended car tire size on the vehicle user manual. If you don’t have manual then same information can also be found on door jamb (place where door connects with the body) inside the car glove box door and with in your car gas tank hatch.
3. Incorrect Reading of Speedometer
Has your car’s speedo needle stuck at 80 MPH while you are going in 20 MPH? This happens when the PCM or ECU unit has trouble accessing and determining the actual speed. That resulted in the speedo getting the wrong output and showing an incorrect reading. This will also happen when your speedo meter is accurately calibrated for wrong size tires.
Steps to correct the incorrect reading of speedometer
Use a scan tool and insert it into your computer and car OBD II port (underneath). Then, access and wait for all the fault codes to pop on in the pending list. Reset the fault codes like you usually do by hitting the Start button.
To calibrate for the right size tire first select your vehicle model and year of release on scanner. Then go to anti lock brake, then functional test, and then tire size calibration. Now put in the VIN number. If you put new size tires then go to new size tires go to new tires.
Scanner will ask to press and hold brake. Then will you show to all the standard tire sizes. Select the tire size you have put on your vehicle. Your speedo meter is calibrated.
Here is a video of this entire setup
Issue 4: Speedometer at Zero
If your speedo indicator needle stays in the 0 and doesn’t move at all, this means the fuse or wires are burnt. Sometimes it can also occur if the speedometer needs replacement.
Steps to repair speedometer that remains at zero
- Locate the fuse compartment in your 97 GMC Sierra by checking the owner’s manual.
- Mostly Fuse is located at bottom side, right at the end of the steering wheel.
- Remove that and insert a new fuse. Test it out.
- If still the speedo stays at 0 MPH, then the speedometer needs an inspection.
- Remove the front and side panels (around the speedo) using a pry bar.
- Take out the dash trim.
- Take a screwdriver to detach 3 screws (in most cases).
- Then, carefully unplug the instrumental cluster.
- Take a new instrumental cluster and plug the wire into it. Push it a little to properly insert the plugs into the place.
- Insert the 3 screws and tighten them out using the screwdriver.
- Add the dash trim and press it to sit properly.
- Place the front and side panels around the speedo and fix them by applying slight pressure. Be sure not to break them.
- Calibrate the speedometer using the OBD II to match the reading.
Ending Note
After learning about the 1997 GMC Sierra speedometer problems, you should try the given techniques to fix those as it doesn’t cost much to attempt.
Solving the issue from Autoshop or via an expert will potentially need around $900 to $1,000 or more based on the causes.
So, I hope this guide leads you to the right solution to fix the real issue. Best of Luck!
