When your odometer functions correctly, it displays accurate mileage readings, which are important for various reasons, including your vehicle’s sale value, maintenance, and insurance.
The odometer goes on and off – why?
The gears that run your odometer are broken
Manufacturers often fit older vehicles with analog odometers which rely on plastic gears and cables that can easily snap. These gears and cables connect the input shaft inside your vehicle’s instrument cluster with the output shaft located in the transmission.
Whenever the tires are in motion, the output shaft will force the cable to spin, which will allow the different gears on your vehicle’s odometer to move. This usually depends on how the different gears were calibrated depending on your vehicle’s tire size.
If these plastic gears are worn-out or broken, the odometer will malfunction and display inaccurate readings.
The best way to fix this problem is by replacing the worn-out or broken gears with new ones. If the problem persists after replacing the gears, it is best to take your vehicle to an experienced mechanic for further diagnosis.
Faulty wiring may be the primary reason why the instrument panel is malfunctioning. These wires rub through the steering column, which will cause a short with the Body Control Module (BCM).
A clear indication of faulty wiring inside your vehicle is when your vehicle’s odometer starts displaying the highest reading possible. If you notice this problem, consider taking your vehicle to a professional mechanic for a quick diagnosis.
Broken solder joint
Cracked or broken solder joints inside the instrument panel will cause poor or no contact with the odometer. Some of the main reasons why solder joints may crack or break include repeated movement, excess heat, overheating engine components, and weakness in the joint from the beginning.
To identify the exact point where the solder joint is broken, you will need to look at the printed circuit board using a magnifying glass.
The best way to fix a broken solder joint is by re-soldering it with fresh solder.
Bad speed sensor
A speed sensor is undoubtedly one of the most important components of your vehicle. The speed sensor regulates cruise control, the flow of fuel, and ignition timing, and indicates the speed. Therefore, having a faulty speed sensor will affect your vehicle’s safety on the road.
If your vehicle’s odometer is repeatedly going on and off, it may be due to a bad or failing speed sensor.
You can tell that your vehicle’s speed sensors have gone bad if you notice cruise control glitches, inability to apply your torque converter clutch, the check engine light on the dashboard, and power loss.
The best way to fix this problem is by replacing the faulty speed sensors using new ones. You can do this by yourself if you know exactly how to remove the instrument cluster safely, or you can simply get a professional mechanic to do it for you.
Faulty Electronic Control Unit (ECU)
The ECU is a small component that acts as your vehicle’s computer brain and controls all engine functions. The ECU controls specific engine functions and collects information from all internal combustion engine components to ensure that everything functions properly.
If the ECU is faulty, it will result in fuel inefficiency, power loss, and spark loss, plus the odometer will start going on and off.
Unfortunately, diagnosing and repairing ECU problems is not an easy task. Your best chance of getting an accurate diagnosis is by taking your vehicle to a professional mechanic since they have the right software, tools, and a better understanding of the entire ECU.
Wrong sized fuse
The primary function of the fuse is to protect your vehicle’s wiring. However, you need to get a right-sized fuse to ensure that the wiring is adequately protected. Using a large or small fuse will generate excess heat and cause an insulation breakdown. This will cause the odometer and other gauges to malfunction.
If none of the above problems are to blame for your malfunctioning odometer, the culprit may be a grounding issue. This problem affects the functioning of indicators, gauges, and even dash lights. You will need a mechanic to diagnose this.
How Do I Test If My Odometer Is Broken?
To determine the exact reason why your odometer is going on and off, here are some steps you need to try:
- Turn on the ignition to check whether the odometer is displaying any readings
- Check whether the fuse is displaying light on both sides
- If the fuse is in good condition, remove the entire instrument panel and confirm whether the gauges are working
- Use an ohmmeter to measure the resistance and a voltmeter to measure the battery or ignition voltage
- Pull out the entire dashboard to check whether the solder joints are in contact with the odometer
What Happens If My Odometer Is Broken?
You may get in trouble with the law if you sell your car but the odometer is not displaying an accurate reading because it broke down along the way. Therefore, if your odometer is malfunctioning, you need to get it fixed immediately.
If your odometer breaks, it will not affect your vehicle’s drivability or safety. It is also worth noting that a broken odometer will not affect the functionality of other vehicular components.
How Do You Fix a Broken Odometer?
The following are some solutions you can try to get your broken odometer functioning properly again:
- If the odometer is going on and off due to a bad sensor, replace it with a new one. Since speed sensors are usually mounted at the back of the transmission, you will need to open the instrument cluster.
- Once you have opened the instrument cluster, use compressed air to get rid of dust. You can also use a cloth to wipe the translucent plastic.
- Use a flat head screwdriver to remove the broken gears and replace them with new ones.
- Check the connector at the back of the dashboard to verify that it is inserted properly.
- Consider replacing it with the correct fuse scale if you use an oversized fuse to protect the wiring. For instance, if you have a 15 amp wiring, you should go for a 25 amp fuse.
- Inspect the ECU to ensure that the wiring is done properly.
How Much Does It Cost to Fix a Broken Odometer?
- If labor charges a minimum of $80 and takes 3 hours to fix the odometer, it will cost you $240.
- If labor charges a maximum of $100 and takes 5 hours to fix the odometer, it will cost you $500
- On an average, if labor charges $90 and takes 4 hours to fix the odometer, it will cost you $360