How to Test a Golf Cart Speed Sensor (Bad Sensor Symptoms)

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(Last Updated On: July 8, 2020)

What is a Golf Cart Speed Sensor?

A golf cart speed sensor interprets the rpm of the motor and passes on this detail to a speed controller present in the golf cart. This helps to keep control over several motor functions including roll-away protection and regenerative braking.

As the name indicates, this device is a part of the motors used in golf carts. There are essentially three types of golf cart speed sensors; electrical, mechanical and magnet-based.

A golf cart uses either an AC or a DC motor. DC wound motors don’t incorporate golf cart speed motors because they don’t have many features such as roll-away protection and regenerative braking.

However, AC motors and DC powered separately excited motors with shunt winding make use of these sensors. It’s also worth noting that not all DC powered separately excited motors use this sensor.

Roll-away protection is essential for the safety of the golf cart. If the parking brake is not activated, the golf cart tends to roll off when it is in a neutral position and stopped in an incline.

Please note that rolling will occur in neutral only at a predetermined speed. This will help you to get control over the cart before it crashes.

Regenerative braking is a process that causes the golf cart motor to act as a generator. This helps in setting the speed of the cart to a preset rpm. Moreover, the power generated as a result of this can help in recharging the golf cart batteries.

Usually, the sensors in separately excited DC golf cart motors with shunt windings utilize electromagnetic power to interpret the motor rpm. There will be a magnet in the motor and the sensor at the closed end. The sensor analyzes the reaction of the magnet with the magnetic field inside the golf cart motor.

A mechanical golf cart speed sensor features a slotted disk that passes alongside an eye or a reader head. Based on the number of slots read in a minute, a calculation is made in the speed controller to decide the rpm.

Where is the Speed Sensor Found on a golf cart?

The speed sensor in a Club Car Precedent golf cart is located on the back of the motor. To remove the sensor, unplug the cables behind the motor. You can use a 5/16-inch socket to remove the pigtail connector and pop off the plastic housing that encases the speed sensor.


Symptoms of a Bad Speed Sensor

These are some symptoms of a bad speed sensor:

  1. Your golf cart may move very slowly as if it’s creeping along or it may move at an erratic speed.
  2. You may experience stuttering in your golf cart like when you have a bad battery or there is a low voltage problem.
  3. A broken or damaged magnet on the motor can result in a bad speed sensor. If this is replaced with a new magnet, the speed sensor will begin to function properly. Alternatively, the magnet could have just come loose. If so, all that you have to do is to tighten the magnet.
  4. Your golf cart may go fast initially and slow down drastically on its own after some time. This will happen repeatedly in a cyclic pattern. In such a situation, the car is said to be in limp-mode.


How to Test the Speed Sensor

There are many ways you can test the speed sensor on a golf cart. Two methods of testing your speed sensor are the following:

  1. Activate the Run/Tow switch of the golf cart by keeping it in Run position and try to push the cart. If your speed sensor is good, you should hear a beep and experience resistance to the pushing action by slowing down. If the sensor is bad, your cart will start rolling. Remember that if the switch is in Tow position, the cart will definitely roll.
  2. Ensure that the 3-pin plug from the sensor is connected and place a wire-piercing probe on the output green wire. Lift one wheel of the golf cart and turn it one full rotation with your hand. The voltage reading should change from 0V to 5V 24 times for one full revolution.

You can also look up the “Golf cart speed sensor troubleshooting” section above to have an understanding of the Precedent IQ/DS IQ Speed Sensor Test.

It might also be worthwhile knowing about speed controller testing of your golf cart. This can be a bit challenging but is definitely worth it.

The following steps tell you how to troubleshoot the speed controller of an EZ-GO golf cart:

  1. Turn the maintenance switch under the seat of your golf cart to tow-maintenance mode.
  2. Disconnect the negative cable from the battery. This is the black cable connected to the battery post. Remember that it’s essential that you flip the maintenance switch before you begin the replacement of the cable.
  3. Remove the cover present on top of the speed controller and reconnect the negative cable of the battery.
  4. Check the wiring connection thoroughly. They should be well-connected and attached properly. Also, make sure that there is no corrosion, breakage or any form of interference among the wires.
  5. Connect the positive and negative probes of a voltmeter to the corresponding battery terminals and note down the battery voltage.
  6. Keep the positive probe of the voltmeter above the solenoid post, which is nearest to the battery and check the reading. This must be the same as the battery voltage noted above. A variation indicates that the solenoid has a wiring issue.
  7. Repeat the above step by keeping the voltmeter probe on the solenoid post that is away from the battery. The battery voltage should be higher than the observed voltage by at least three volts. If the readings are the same, then the solenoid is faulty.
  8. Connect the positive and negative probes of the voltmeter to the B+ and M terminals of the speed controller respectively and check for a voltage rise from 0 to the battery voltage as you accelerate the cart. There will be no rise in the case of a faulty speed controller.

How to Replace a Speed Sensor

You can check out the tips given here to help you to replace the speed sensor of your golf cart.

  1. Remove the snap ring that holds the speed sensor on to the motor of your golf cart. This will help you to pull out the faulty speed sensor.
  2. You can now put a new one in its place and replace the snap ring. Ensure that the Run-Tow switch is in Tow mode when you do this.
  3. If the speed sensor does not come out after you have tried the above, you might try spraying some lube on it. The sensor might have got stuck because of some micro grit that is holding it in.
  4. Alternatively, you might try punching a small hole in it with a small screwdriver and by picking this small hole to pull out the speed sensor.


Golf Cart Speed Sensor Troubleshooting

A speed sensor push test can help you troubleshoot the problem with the speed sensor of your golf cart if it gets into limp mode.

  • Ensure that the golf cart is not in sleep mode. To do this, you have to drive the cart ahead a little distance and ensure that the cart is up and running.
  • Place the F&R switch in any of the three positions and move the Run/Tow switch to the Run position.
  • Push the golf cart to stimulate a roll-away action. The cart will show resistance to the action.
  • As the cart is slowing, the reverse buzzer will give out a series of beeps.

If you’re able to push the golf cart freely without any resistance, it indicates that there is no communication between the speed sensor and the controller. This is because of a speed sensor failure.


Precedent IQ/DS IQ Speed Sensor Test

The Precedent golf carts feature either an Excel or IQ system while the DS club cars have an IQ system. Both systems have almost the same style of functioning.

The IQ system features a shunt-wound controller/motion combination. This combination is identical to the Regen 1 and Regen 2 of the older PowerDrive Plus carts.

In the Regen carts, unplugging the speed sensor will remove the option of regenerative motor braking.

In Excel or IQ cars, this action will set the golf cart to limp mode and prevent it from running at full speed. You’ll encounter the same problem if the speed sensor is plugged in but has gone bad. A broken motor magnet can also set off the limp-mode in a golf cart.

One more tip for troubleshooting the speed sensor is to kick in the solenoid when it’s moved front and back with and without the speed sensor plugged in. If this does not happen with the speed sensor plugged in, then you’ll have to change the speed sensor.

Another indication of a faulty golf cart speed sensor is that the regenerative braking fails to engage.

You might also want to check all inputs like the key switch, the throttle sensor and the tach sensor. Likewise, check the IE voltage across the A and F terminals of the motor during the fail mode.

Troubleshooting the speed controller of an EZ-Go cart

The following steps can guide you on how to troubleshoot the speed controller of your EZ-Go cart.

  • Flip the maintenance switch of your golf cart to tow-maintenance mode. This switch is usually located below the seat of the golf cart.
  • Unplug the black wire or negative battery cable and remove the cover of the speed controller. Reconnect the negative cable like how it was originally connected.
  • Check all the wire connections to make sure that they’re plugged in tightly as well as free of corrosion or breaks. Tighten loose wires and replace damaged ones accordingly.
  • Check the speed controller battery voltage by connecting the negative and positive probes of the voltmeter to the battery.
  • Check the voltage reading of the solenoid and compare it with that of the battery. To take the solenoid’s voltage reading, place the positive probe of the voltmeter on top of the solenoid post that is closest to the battery.
  • If the battery and solenoid readings are the same, then the problem is with the solenoid. On the other hand, if the battery voltage is not higher than the solenoid voltage by a minimum of 3 volts, it indicates a faulty resistor that calls for a resistor replacement.
  • Connect the positive probe of the voltmeter to the B+ terminal of the speed controller and the negative probe to the M terminal. The reading should initially be 0 and slowly rise to the battery voltage value as you activate the accelerator. If there is no voltage reading, you have a problematic speed controller.


EZGO PDS Speed Sensor Troubleshooting

Some tips for troubleshooting the speed sensor of your EZGO PDS golf cart are given below.

  • The sensor may have got damaged because the connecting cable got pulled hard for some reason. In this case, you may need to fix a new sensor assembly.
  • The magnetic disk on the motor shaft may have come loose. Tightening this is likely to make the speed sensor start functioning properly once again.
  • Check the spacing between the speed sensor and the magnetic disk. The inner and outer snap rings must be seated in the grooves of the disk for the right spacing.
  • The golf cart has a faulty speed sensor wiring or speed sensor if you don’t experience any resistance when you push the cart on flat ground or it’s on an incline. Check for proper wiring connection first and if that seems to be fine, do a speed sensor replacement.
  • A broken speed sensor magnet can cause malfunctioning of the speed sensor. If this is replaced with a new magnet, your speed sensor should work properly. You could also check to see if the screw that holds the plate in place over the magnet is intact.


Club Car Speed Sensor Troubleshooting

The Club Car Precedent is generally programmed to travel at specific speeds. These speeds are as follows from the maximum to the minimum.

  • Private speed mode – 19.6 mph
  • Normal golf speed – 14.8 mph
  • Slow golf speed – 13.4 mph
  • Commercial speed – 8.0 mph

If the top speed of your Club Car golf cart shows a sudden drop by half of the starting speed or even slower, the speed sensor is likely to be at fault. This could be either because the sensor is broken or it has gone bad.

Once you replace the speed sensor with a new one, your Club Car will follow the normal speed patterns given above. Often, you can do the installation yourself using some basic hand tools that you’re sure to have.



The speed sensor located behind the motor is an integral part of your electric golf cart. This sensor keeps track of how fast the motor rotates and helps control the speed at which your golf cart travels.

Along with the speed controller, the speed sensor helps in having control over several motor functions so that you can have a safe and hassle-free experience with your golf cart.

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