Riviera V6-231 3.8L VIN C SFI (1989)
Canister Purge Wiring Diagram
CIRCUIT DESCRIPTION:
Canister purge is controlled by a solenoid that allows ported vacuum to purge the canister when energized. The ECM supplies a ground to energize the
solenoid (purge "ON").
If the diagnostic test terminal is grounded with the engine stopped or the following is met with the engine running the purge solenoid is energized (purge
"ON").
A.
Engine run time after start more than 1.0 minute.
B.
Coolant temperature above 80°C (176°F).
C.
Vehicle speed above 5.0 mph (8.0 km/h).
D.
Throttle "OFF" idle. TPS signal above 0.75 volt.
TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart.
1.
Checks to see if CKT 428 is shorted to ground. The solenoid is normally de-energized in this step, so test light should be "OFF."
2.
Completes functional check by grounding "test" terminal. This should normally cause the ECM to ground CKT 428 (purge "ON").
3.
Checks ignition CKT 139.