2.
Probe(+) :Measure the waveform of Vehicle speed sensor at terminal 2.
Probe(-) :Chassis ground.
The Wheel Speed Sensor (WSS) generates a waveform with a frequency according to the speed of the vehicle. The signal generated by the WSS informs the ECM not only if the vehicle speed is low or high but also is stopped the vehicle or not. The ECM uses this signal to control the fuel injection, ignition timing, transmission/transaxle shift scheduling and torque converter clutch scheduling. Also the WSS signal is used to detect rough road driving condition.
he ECM sets DTC P0501 if there is no vehicle speed signal from wheel speed sensor while both engine speed and mass air flow are higher than predetermined threshold during predetermined time.
Item | Detecting Condition | Possible cause |
Monitoring Strategy | ● 1.Signal check High , Low ● 2. Signal interruption ● 3. Rationality check | ● Open in signal line. ● Open in signal line. ● Bad vehicle sensor. ● Open in sensor ground. ● Bad vehicle sensor. |
Threshold value | 2 | ● Vehicle speed : < 5.0 km/h |
3 | ● Vehicle speed : < 3.75 km/h | |
Enable Conditions | 2 | ● Tmot : > 64.5℃(148.1℉) ● Nmot : < 4000rpm , > 3000rpm ● Fuel cut-off |
3 | ● Nmot : > 3000rpm ● Relative charge of cylider : > 49.5% | |
Diagnostic Time | ||
MIL on condition | ● 5 . 0 sec |
Service standard
Approximately 40 Km/h
Service standard
Approximately 40 Km/h
The data shown above is only for reference and there may be a little difference actually.
Drive the vehicle at 40 Km/h on the lifter.
Probe(+) :Measure the waveform of Vehicle speed sensor at terminal 2.
Probe(-) :Chassis ground.
This is the waveform of vehicle sensor when it drives 40Km/h.
The voltage at point ① should be below 0.8V and at poiont ② should be above 7V.
The frequency of vehicle sensor must increase as the RPM increases.
This is the waveform of vehicle sensor when it drives 40Km/h.
-The voltage at point ① should be below 0.8V and at poiont ② should be above 7V.
-The frequency of vehicle sensor must increase as the RPM increases.
If the vehicle speed on scan tool and that of instrument pannel coincide,when driving at 40Km/h, the sensor is normal.
In case there is no symptom and wrong data but DTC is shown
The problem may be intermittent so slightly shake the connector and harness vertically and horizontally to check if there is any data changes
If the data changes normally, the problem was intermittent so erase DTC and verify the same DTC reoccure.
Go to "Terminal and Connector inspection"
In case there is symptom and wrong data with DTC
Check open,short or connector’s connection for VSS.
Check the deterioration of VSS performance.
Go to "Signal circuit inspection"
