– Introduction General Information In–31 5. EVAP Monitor (Fuel tank pressure monitor) IMPORTANT To complete the ”Internal Pressure Readiness” monitor, you must perform a ”Cold Soak” procedure prior to conducting the driving pattern procedure. Cold Soak Preconditions The monitor will not run unless: MIL is OFF Fuel level is approximately 1/2 to 3/4 Altitude is 7,870 feet (2,400 m) or less Cold Soak Procedure (a) Start the engine and allow coolant temperature to reach 176 ° F (80 ° C) or higher (b) Let vehicle cold cold soak for 8 hours or until the difference between IAT and ECT is less than 13 ° F (7 ° C) Examples:
Scenario 1 ECT = 75 ° F (24 ° C) IAT = 60 ° F (16 ° C) Difference between ECT and IAT is 15 ° F (8 ° C) → The monitor will not run because difference between ECT and IAT is greater than 13 ° F (7 ° C) Scenario 2 ECT = 70 ° F (21 ° C) IAT = 68 ° F (20 ° C) Difference between ECT and IAT is 2 ° F (1 ° C) → The monitor will run because difference between ECT and IAT is less than 13 ° F (7 ° C) EVAP MONITOR DRIVING PATTERN (72 km/h) 45 mph (40 km/h) 25 mph Idling IG SW Off Warm up Soak 5 min. 15 min. A18909 1996–2003 ADDITION OF OBD (OTH021U) 31 Author : Date: