The evaporative emission control system prevents hydrocarbon (HC) vapors from the fuel tank from escaping into the atmosphere where they could form photochemical smog. Gasoline vapors are collected in the charcoal canister. The ECM controls the Purge Control Solenoid Valve (PCSV) to purge any collected vapors from the canister back to the engine for combustlon. This valve is actuated by the purge control signal from the ECM and controls fuel vapor from the canister to the intake manifold.
If surge voltage is less than threshold value, the ECM judged as a fault and DTC is set.
Item
Detecting Condition
Possible Cause
DTC Strategy
? Surge voltage is monitored
? Poor connection
? Open or short in EGR S/V circuit
? Defective EGR valve
? Defective ECM
Enable Conditions
? 10=Battery voltage =16V
Threshold value
? Surge voltage < (B+) + 2V
Diagnostic Time
? Continuous
MIL ON condition
? 2 driving cycles
EGR S/V
Normal Parameter at 20? (68?)
Resistance (?)
Approx.35 ~ 45?