If you encounter an unstable or pulsating lcd speedometer (especially when driving at a low speed), please turn on the power of the speedometer and observe the LCD display on the speedometer. It will display the current PPM (pulses per mile) for one or two seconds, and then default to the odometer. If the PPM is much less than the factory PPM of 16000, please recalibrate both. Methods as below:
Normally enter the speedometer calibration mode (full scale).
Press and release the button to lower it to ½ mark (normally).
Drive until the pulse count reaches 32000 (ie 16000 ppm), then stop driving. This does not need to be very precise, as long as it is close to 32,000.
Press the trip button to end the calibration.
Now, before you start driving, you need to recalibrate the GPS by pressing the button on the GPS module (80 on the speedometer).
Now you are ready.
If the above operation is successfully completed, but there are still very small peaks or bounces, but the speed is very slow, please return to the above operation, but double the pulse count to about 64000 pulses (32000 ppm) during the speedometer calibration, and then recalibrate the GPS module once again. A higher number of pulses basically increases the frequency of the speed signal, thereby making the signal smoother.