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Forum > Failed Smog Test > Question

VW Jetta Failed Secondary Air Injection Monitor Not Complete

I went to smog check my 2008 VW Jetta and it failed because of the air pump. They said to keep running it until the air pump gets activated but I already drove 700 miles and its still not complete. Thanks for your help.
Answer:

Sounds like your VW Jetta failed the smog check because the Secondary Air Injection Monitor was not "ready" or complete. It should be noted that the secondary air injection monitor which checks for the performance of the air pump runs mainly when the engine is cold. Once the engine warms up the monitor is done checking the pump. With that said, it's not the number of miles you drive that sets off the air injection monitor, rather the number of cold starts. A cold start is considered starting the engine after the vehicle has sat for at least 8 hours. Since the air injection monitor takes into effect ambient air temperate, it is best to perform a cold start in the mornings.

In this particular case if your driving for 700 included at least 3 cold-starts we'd recommend either following the VW drive cycle we indicate below or seek assistance from a VW dealership or equipped smog station for a diagnosis of your VW's on-board diagnostics system. It is very possible that a parameter required to trigger the air injection monitor is not being met. This can be caused by any number of marginal malfunctions which the ECM (engine control module) can not detect. A specialized VW scan tool can report the condition of each emission sensor and actuator required for emission monitoring. Take extra caution when performing the drive cycle on public roadways. If you feel you may be unable to perform the drive cycle safely, please seek assistance.

How to Perform a VW Jetta 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.


posted by SmogTips Support

 

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