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H4SO U5

DTC P0503 VEHICLE SPEED SENSOR "A" INTERMITTENT/ERRATIC/HIGH

1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of vehicle speed sensor. Judge as NG when high vehicle speed (300 km/h (186.4 MPH) or more) is still present under the driving condition of the vehicle running at a certain speed.

2. ENABLE CONDITION

Enable Conditions:






3. GENERAL DRIVING CYCLE
Perform diagnosis continuously during deceleration fuel cut at an engine speed of less than 4000 rpm.

4. DIAGNOSTIC METHOD

- Abnormality Judgment
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.






Time Needed for Diagnosis: 4000 ms

Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

- Normality Judgment
Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time.






Time Needed for Diagnosis: Less than 1 second

5. DTC CLEAR CONDITION
- When the OK idling cycle is completed 40 times in a row
- When "Clear Memory" is performed

6. MALFUNCTION INDICATOR LIGHT CLEAR CONDITIONS
- When the OK driving cycle is completed 3 times in a row
- When "Clear Memory" is performed

7. FAIL SAFE
- Vehicle speed sensor signal process: Vehicle speed = 10 km/h (6 MPH)
- ISC control: Open loop compensation is set to (1 g (0.04 oz)/s). Not allowed ISC feedback volume calculation.
- Radiator fan control: Both main and sub fan ON
- Tumble generator valve control: Open the tumble generator valve.

8. ECM OPERATION AT DTC SETTING
Memorize the freeze frame data. (For test mode $02)