Terms Definitions Chart

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Monitor description

Description of what the ECM monitors and how it detects malfunctions (monitoring purpose and its details).

Related DTCs

A group of diagnostic trouble codes that are output by ECM based on same malfunction detection logic.

Typical enabling condition

Preconditions that allow ECM to detect malfunctions. With all preconditions satisfied, ECM sets DTC when monitored value(s) exceeds malfunction threshold(s).

Sequence of operation

Order of monitor priority, applied if multiple sensors and components are involved in single malfunction detection process. Each sensor and component monitored in turn and not monitored until previous detection operation completed.

Required sensor/components

Sensors and components used by ECM to detect each malfunction.

Frequency of operation

Number of times ECM checks for each malfunction during each driving cycle. "Once per driving cycle" means ECM only performs checks for that malfunction once during single driving cycle. "Continuous" means ECM performs checks for that malfunction whenever enabling conditions are met.


Minimum time for which ECM must detect continuous deviation in monitored value(s) in order to set DTC. Timing begins when Typical

2007 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Sequoia

Enabling Conditions are met.

Malfunction thresholds

Value beyond which ECM determines malfunctions exist and sets DTCs.

MIL operation

Timing of MIL illumination after malfunction detected. "Immediate" means ECM illuminates MIL as soon as malfunction detected. "2 driving cycle" means ECM illuminates MIL if same malfunction detected second time during next sequential driving cycle.

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