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chevy truck speedometer problems
Speedometer failure occurs.
Fault analysis: After disassembling and inspecting the odometer sensor, you will find that the driven gear of the odometer sensor has broken into two parts, and the lower gear has disappeared. Open the side cover of the transmission, and the broken driven gear cannot be found. After disassembling and inspecting the transmission, you will find many plastic particles in the oil. It indicates that the driven gear has been broken. Check that the axial clearance of the odometer driving gear on the differential is relatively large and loose. It may be that the driving gear is loose, which causes the driven gear to swing back and forth, eventually leading to fracture and breaking.
Troubleshooting: The fault can be eliminated after replacing the driving gear and the damaged driven gear.
The causes are as follows: 1. If the speed sensor is damaged, the speedometer will not move. Check whether the speed sensor has any fault. If it has any fault, replace it in time; 2. If the speedometer is damaged, the speedometer may not move, but check whether the circuit of the speedometer is falsely connected or short circuited, if it is repaired in time; 3. Check whether there is any fault in the sensor driving mechanism, and the poor contact of the connecting circuit will also cause the speedometer to stop moving; 4. Use the diagnostic apparatus to take out the fault code, which can solve the problem more quickly
When the vehicle is driving, the speedometer will suddenly drop to the zero position, and then return to the normal position automatically dozens of seconds later. Other meters such as tachometer, water temperature gauge and fuel gauge indicate normally.
Fault diagnosis: This phenomenon is an accidental fault. The fault did not reappear during the test run. According to experience, the possible causes are: ① The ignition system or generator interferes with the instrument; ② There is virtual connection in the vehicle speed sensor or connector and circuit.
Because it is time to replace the spark plug, it was decided to replace the spark plug first. The result was no effect, and the fault occurred again.Troubleshooting: After replacing the vehicle speed sensor, the fault is eliminated.
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