DTC P0502: Vehicle Speed Sensor Circuit Low Input

Detect the open or short circuit of vehicle speed sensor.

Judge NG when low vehicle speed (0 km/h (0 MPH)) remains whereas it seemed to be in a usual driving speed.

On under 4000 rpm engine : Perform the diagnosis continuously during fuel cut in deceleration.

• Abnormality Judgment 

  Judge NG when the continuous time of completing the malfunction criteria below becomes more than 4 seconds.

  Judgment Value 

  JUDGMENT VALUE CHART
  
  

  Malfunction Criteria	Threshold Value
  Vehicle speed	< 1

  Time Needed for Diagnosis:  4 seconds

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

• Normality Judgment 

  Judge OK and clear the NG when all malfunction criteria below are completed.

  Judgment Value 

  JUDGMENT VALUE CHART
  
  

  Malfunction Criteria	Threshold Value
  Vehicle speed	"GREATER THAN EQUAL TO" 1
  Starter switch	OFF
  Time after starter switch ON --> OFF	"GREATER THAN EQUAL TO" 3 seconds

• When the OK idling cycle was completed 40 times in a row
• When "Clear Memory" was performed

• When the OK driving cycle was completed 3 times in a row
• When "Clear Memory" was performed

• Accelerator sensor signal process: Not allowed all closed points learning.
• Vehicle speed sensor signal process: Vehicle speed = 10 km/h (6 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: Set the open loop compensation to specified value (1 g/s). Not allowed ISC feedback volume calculation.
• Air conditioner control: Not allowed air conditioner cut at accelerating.
• Radiator fan control: Hi drive both main/sub.
• Judge gear ratio: Control as gear fixed on 6th.
• Tumble generator valve control: Open the tumble generator valve.

Memorize the freeze frame data. (For test mode $02)