Outline Of Diagnosis

• When cold, the abnormality in the control of target engine speed increase is detected. (P050A) 

Judge as NG if the exhaust gas temperature diagnosis or idle speed diagnosis is NG.

• Exhaust gas temperature diagnosis

Judge as NG when the estimated exhausted gas temperature in 14 seconds after the cold start is below the specified value.

• Idle speed diagnosis

Judge as NG when actual engine speed is not close to target engine speed at cold start.

• Detect malfunctions of the catalyst advanced idling retard angle control. (P050B) 

Judge as NG when ECM is not controlling the angle properly during catalyst advanced idling retard angle control.

• Final ignition timing diagnosis

Judge as NG when actual retard amount is under the specified value at cold start.