Toyota Corolla Quiz
Diagnostics

Definition of terms

In this manual: Diagnostics
Introduction — 31Preparation — 32Service specifications — 19Diagnostics — 497Engine control system — 6Fuel — 13Emission control — 28Exhaust — 3Cooling — 13Lubrication — 7Ignition — 3Starting & charging — 13Front suspension — 12Rear suspension — 9Tire & wheel — 1Drive shaft / propeller shaft — 15Brake — 42Automatic transmission / trans — 47Clutch — 19Steering column — 9Power steering — 11Heater & air conditioner — 20Supplemental restraint system — 27Seat belt — 12Lighting — 18Wiper & washer — 9Audio & visual — 12Wiring — 1Communication system — 1Windshield/windowglass/mirror — 31Seat — 10Theft deterrent & door lock — 10Sliding roof/convertible — 8Engine hood/door — 12Exterior/interior trim — 20Vehicle control system — 1Cruise control — 5Maintenance — 8
~1min read
Term Definition
Monitor description Description of what the ecm monitors and how it detects malfunction (monitoring purpose and its details).
Related dtcs Diagnostic code
Typical enabling condition Preconditions that allow the ecm to detect malfunction.

With all preconditions satisfied, the ecm sets the dtc when the monitored value(s) exceeds the malfunction threshold(s).
Sequence of operation The priority order that is applied to monitoring, if multiple sensors and components are used to detect the malfunction.

While another sensor is being monitored, the next sensor or component will not be monitored until the previous monitoring has concluded.
Required sensor/components The sensors and components that are used by the ecm to detect malfunction.
Frequency of operation The number of times that the ecm checks for malfunction per driving cycle.
  • Once per driving cycle” means that the ecm detects malfunction only one time during a single driving cycle.
  • Continuous” means that the ecm detects malfunction every time when enabling condition is met.
Duration The minimum time that the ecm must sense a continuous deviation in the monitored value(s) before setting a dtc. This timing begins after the ”typical enabling conditions” are met.
Malfunction thresholds Beyond this value, the ecm will conclude that there is malfunction and set a dtc.
Mil operation Mil illumination timing after a defect is detected.
  • Immediately” means that the ecm illuminates the mil the instant the ecm determines that there is malfunction.
  • 2 Driving cycle” means that the ecm illuminates the mil if the same malfunction is detected again in the 2nd driving cycle.

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A quick Toyota Corolla quiz: every answer comes with an explanation and a link to the manual page.