Lean protection is designed to protect the engine from an overly lean running condition, and also alert the driver to a potential problem.
Lean protection works by monitoring a wideband oxygen sensor, and performing a engine cut when the air/fuel ratio rises above a preset level for a designated time period. There are two lean protection parameters, so that two different air/fuel ratio to load relationships can be used.
Maximum Lambda is the maximum allowable air/fuel ratio for the lean protection, measured as an air/fuel ratio.
Engine Load is the minimum engine load for the lean protection to activate.
Trigger Time is the time period which the air/fuel ratio needs to leaner than the maximum lambda for the lean protection to activate. This is to remove false protection triggering from throttle transients and engine load changes.
Once lean protection is triggered, the check engine light will illuminate and the engine will be cut. The engine will be restored once the throttle is released or the engine rpm drops below 2000 rpm.
Overheating Protection
This illuminates the check engine light, sets an error code (#11) and optionally rev limiter if the engine is overheating.
The Overheating Temperature is the temperature at which the engine is considered overheating.
The Rev Limiter will limit engine speed if the engine is overheating.
To clear the error code the ignition must be switched off. Note that if bubbles are present in the cooling system the protection may trigger earlier than expected.
Radiator Fan
It is possible to force on the radiator fan from ECU.
Check Override radiator fan control to force the radiator fan on at the Temperature and off at the Maximum Vehicle Speed.