Maintenance and care -> Emission inspection and maintenance (I/M) programs for Your Toyota Prius 4 Door Third Generation (2010-2015)

4-2. Maintenanc e  
Emission inspection and maintenance (I/M) programs  
Some states have vehicle emission inspection programs which  
include OBD (On Board Diagnostics) checks. The OBD system moni-  
tors the operation of the emission control system.  
If the malfunction indicator lamp comes on  
The OBD system determines that a problem exists somewhere  
in the emission control system. Your vehicle may not pass the I/  
M test and may need to be repaired. Contact your Toyota dealer  
to service the vehicle.  
Your vehicle may not pass the I/M test in the following situa-  
tions:  
When the 12-volt battery is disconnected or discharged  
Readiness codes that are set during ordinary driving are  
erased.  
Also, depending on your driving habits, the readiness codes  
may not be completely set.  
4
When the fuel tank cap is loose  
The malfunction indicator lamp comes on indicating a tempo-  
rary malfunction and your vehicle may not pass the I/M test.  
When the malfunction indicator lamp still remains on after  
several driving trips  
The error code in the OBD system will not be cleared unless the  
vehicle is driven 40 or more times.  
If your vehicle does not pass the I/M test  
Contact your Toyota dealer to prepare the vehicle for re-testing.  
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