We believe what the smog technician is referring to is the OBD "Emission Monitors" needing to be reset; which can only occur by driving your VW for approximately 200-300 miles and over the course of a few days. Without the emission monitors being Ready/Complete, the vehicle can not pass the smog test.
Each emission monitor (of which there are six) require specific operating conditions before the monitor test is initiated. In most cases, the monitors should run during normal vehicle operation. However, due to different driving habits, the criteria required to run a monitor may not always be met. By following the Volkswagen Passat drive cycle below all emission monitors will run. The Volkswagen Passat drive cycle must be followed accurately.
How to Perform a Volkswagen Passat Drive Cycle
Take extra caution when performing the drive cycle on public roadways. Perform the drive cycle at your own risk. You may choose to have a Volkswagen dealer or repair shop complete monitor testing while your VW is stationary via the use of a scan tool. An advanced scan tool will have the capability to command your VW's engine control module (ECM) to run readiness code diagnostic tests in a special operational mode. If these tests run successfully, all eight readiness monitors will be set to “ready”, and your VW will not need to be driven through a drive cycle.
The VW OBD-II drive cycle is an eight-step process. An explanation of each step is provided below. Total drive cycle time is 12 minutes.
NOTE: Do not leave the key on prior to the cold start or the oxygen sensor (O2S) heater monitor may not run.
Step 1: Cold Start — The ECM determines the presence of a cold start by comparing the engine coolant temperature to the ambient air temperature during startup. The engine is considered cold when:
• Engine coolant temperature is below 122°F.
• Engine coolant and intake air temperatures are within 11°F of each other at startup. During this period, the O2S heater, misfire, AIR, fuel system, and EVAP monitors run.
Step 2: Idle 2 1/2 Minutes — Turn the air conditioning (A/C) and headlights on to help the misfire monitor—the additional electrical loads help even out combustion pulses. During this period, the O2S heater, AIR, EVAP, misfire, and possibly fuel system (if operating in closed loop) monitors run.
Step 3: Accelerate — Prior to accelerating, turn off the A/C and headlights (if you had them on during step 2). Open the throttle halfway until you reach 55 mph. During acceleration, the misfire, fuel system, and EVAP monitors run.
Step 4: Steady State Cruise 3 Minutes — During this portion of the cycle, the O2S, AIR, EGR, EVAP, misfire, and fuel system monitors run.
Step 5: Decelerate — Gradually coast down to 20 mph without applying the brakes. Also, on manual transmission vehicles, remain in high gear and do not press the clutch. During this period, the EGR, EVAP, and fuel system monitors run.
Step 6: Accelerate—Apply ¾ throttle until reaching 60 MPH. During acceleration, the misfire, fuel system, and EVAP monitors run.
Step 7: Steady State Cruise 5 Minutes — During this period, the CAT, O2S, AIR, EGR, EVAP, misfire, and fuel system monitors run.
Step 8: Decelerate — Gradually coast down to 0 mph without applying the brakes. Also, on manual transmission vehicles, remain in high gear and do not press the clutch. During this portion of the Drive Cycle, the EGR, EVAP, and fuel system monitors run.
NOTE: If the CAT is marginal and the battery was disconnected prior to the drive cycle, it may take up to five separate drive cycles in order to determine the state of the catalytic converter.
