Toyota Tacoma 2015-2018 Service Manual: Definition Of Terms

Monitor Description

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

Related DTCs

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

Typical Enabling Conditions

Preconditions that allow the ECM to detect malfunctions.

With all preconditions satisfied, the ECM stores a DTC when the monitored value(s) exceeds the malfunction threshold(s).

Sequence of Operation

Order of monitor priority, applied if multiple sensors and components are involved in a single malfunction detection process.

Each sensor and component is monitored in turn and subsequent items are not monitored until the previous detection operation completes.

Required Sensors/Components

Sensors and components used by the ECM to detect each malfunction.

Frequency of Operation

Number of times the ECM checks for each malfunction during each driving cycle.

"Once per driving cycle" means that the ECM only checks for malfunctions once during a single driving cycle.

"Continuous" means that the ECM checks for malfunctions whenever enabling conditions are met.

Duration

Minimum time for which the ECM must detect continuous deviation in monitored value(s) in order to store a DTC. Timing begins when typical enabling conditions are met.

Typical Malfunction Thresholds

Value beyond which the ECM will determine that there is a malfunction and store a DTC.

MIL Operation

Timing of MIL illumination after a malfunction is detected.

"Immediate" means that the ECM illuminates the MIL as soon as a malfunction is detected.

"2 driving cycles" means that the ECM illuminates the MIL if the same malfunction is detected again during the next driving cycle.