Toyota Corolla (E120): Inspection procedure
Hint
: read freeze frame data using the hand-held tester or the obd ii scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was lean or rich, etc. At the time of the malfunction.
1 Check other dtc output(in addition p0121)
- Connect the hand–held tester or the obd ii scan tool to the dlc3.
- turn the ignition switch on and push the hand–held tester or the obd ii scan tool main switch on.
- select the item ”diagnosis / enhanced obd ii / dtc info / current codes”.
- read the dtcs.
Result:
Hint
: if any other codes besides p0121 is output, perform the troubleshooting for those dtcs first.
Go to relevant dtc chart
Other materials:
Circuit description
The rear heated oxygen sensor is used to monitor oxygen concentration in the
exhaust gas. For optimum
catalytic converter operation, the air fuel mixture must be maintained near the
ideal ”stoichiometric” ratio.
The heated oxygen sensor output voltage changes suddenly in the vicinity of ...
Overhaul
1. Remove oil filler cap sub–assy
Remove the oil filler cap from the cylinder head cover.
2. Remove oil filler cap gasket
Using a screwdriver, remove the gasket from the oil filler
cap.
3. Remove ventilation valve sub–assy
Remove the ventilation valve from the cyl ...
Emission inspection and maintenance (I/M) programs
Some states have vehicle emission inspection programs which include OBD (On
Board Diagnostics) checks. The OBD system monitors 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 cont ...