P0721

Component Location





General Description

The Output Speed Sensor outputs pulse-signals according to the revolutions of the output shaft of the transmission. The Output Speed Sensor is installed in front of the Transfer Drive Gear to determine the Transfer Drive Gear rpms by counting the frequency of the pulses. This value, together with the throttle position data, is mainly used to decide the optimum gear position.

DTC Description

The TCM sets this code if the calculated value of the signals is noticeably different from the value calculated, using the Vehicle Speed Sensor output, when the vehicle is running faster than 18.6MPH(30km/h). The TCM will initiate the fail safe function if this code is detected.

DTC Detecting Condition





Specification

Input shaft & Output shaft speed sensor
- Type : Hall sensor
- Current consumption : 22mA(MAX)
- Sensor body and sensor connector have been unified as one.

Diagnostic Circuit Diagram





Signal Waveform








Fig 1) INPUT SIGNAL -> LOW SPEED
Fig 2) INPUT SIGNAL -> HIGH SPEED

Monitor GDS Data

1. Connect scantool to data link connector(DLC)
2. Engine "ON".
3. Monitor the "INPUT SPEED SENSOR" parameter on the scantool.
4. Drive the vehicle

Specification :Increasing Gradually

























Fig 1) P,N
Fig 2) "R"
Fig 3) "4" Range
Fig 4) "3" Range
Fig 5) "2" Range
Fig 6) "L" Range
5. Does "input speed sensor " follow the referance data?






Terminal and Connector Inspection

1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?






Signal Circuit Inspection

1. Ignition "ON" & Engine "OFF".
2. Disconnect the "OUTPUT SPEED SENSOR" connector.
3. Measure voltage between "Signal" terminal of the OUTPUT SPEED SENSOR harness connector and chassis ground.

Specification :Approx. 5V


4. Is voltage within specifications ?






Power Circuit Inspection

1. Ignition "ON" & Engine "OFF".
2. Disconnect the "OUTPUT SPEED SENSOR" connector.
3. Measure voltage between "Power supply" terminal of the OUTPUT SPEED SENSOR harness connector and chassis ground.

Specification :Approx. B+


4. Is voltage within specifications ?






Ground Circuit Inspection

1. Ignition "ON" & Engine "OFF".
2. Disconnect the "OUTPUT SPEED SENSOR" connector.
3. Measure resistance between "Ground" terminal of the OUTPUT SPEED SENSOR harness connector and chassis ground.

Specification :Approx. 0 Ohms


4. Is resistance within specifications ?






Component Inspection

Check "OUTPUT SPEED SENSOR"
1. Ignition "OFF"
2. Disconnect the "OUTPUT SPEED SENSOR" connector.
3. Measure resistance between terminal "1","2" and "2","3' and "1","3" of the "OUTPUT SPEED SENSOR" connector.

Specification :Refer to " Reference data"


4. Is resistance within specifications?
[Reference data]










Check PCM/TCM
1. Ignition "ON" & Engine "OFF".
2. Connect "OUTPUT SPEED SENSOR" connector.
3. Install scantool and select a SIMU-SCAN,
4. Simulate frequency to OUTPUT SPEED SENSOR signal circuit.








Fig 1) OUTPUT 150Hz -> 133rpm
Fig 2) OUTPUT 250Hz -> 222rpm
** The values are subject to change according to vehicle model or conditions
5. Is "OUTPUT SPEED SENSOR" signal value changed according to simulation frequency?






Verification of Vehicle Repair

After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
2. Using a scantool, Clear DTC.
3. Operate the vehicle within DTC Enable conditions in General information.
4. Are any DTCs present ?