Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Definition Of Terms

Monitor Description

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

Related DTCs

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

The priority order that is applied to monitoring if multiple sensors and components are used to detect the malfunction.

While one sensor is being monitored, the next sensor or component will not be monitored.

Required Sensors/Components

The sensors and components that are used by the ECM to detect malfunctions.

Frequency of Operation

The number of times that the ECM checks for malfunctions per driving cycle.

"Once per driving cycle" means that the ECM detects a malfunction only once during a single driving cycle.

"Continuous" means that the ECM detects a malfunction every time the enabling conditions are met.

Duration

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

Typical Malfunction Thresholds

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

MIL Operation

MIL illumination timing after a malfunction is detected.

"Immediate" means that the ECM illuminates the MIL the instant the ECM determines that there is a malfunction.

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

Component Operating Range

Normal operation range of sensors and solenoids under normal driving conditions.

Use these ranges as a reference.

They cannot be used to judge if a sensor or solenoid is defective or not.