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P0503

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

1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of vehicle speed. 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 continually during a deceleration fuel cut, at less than 4000 rpm.

4. DIAGNOSTIC METHOD

Abnormality Judgment
Judge as NG when the continuous time of meeting the malfunction criteria below becomes 4 seconds or more.






Time Needed for Diagnosis: 4 seconds

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

Normality Judgment
Judge as OK and clear the NG when all of the following criteria are established.






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 CONDITION
- When the OK driving cycle is completed 3 times in a row
- When "Clear Memory" is performed

7. FAIL SAFE
- Accelerator sensor signal process: Not allowed fully closed point learning. (Hold previous value)
- Vehicle speed sensor signal process: Vehicle speed = 10 km/h (6.21 MPH)
- Fuel cut control: Not allowed vehicle speed 0 km/h (0 MPH) fuel cut. Normally the high vehicle speed fuel cut performs on "and" of vehicle speed condition and engine speed, but perform the fuel cut only on engine speed condition (4,800 rpm or more).
- ISC control: Open loop compensation is set to (1 g/s). Not allowed ISC feedback volume calculation.
- Air conditioner control: Not allowed air conditioner cut at accelerating.
- Radiator fan control: Both main and sub fan are in High driving.
- Gear ratio judgment: Control as fixed in sixth gear
- Tumble generator valve control: Open the tumble generator valve.

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