Oil Pressure Sensor and Engine Protection
This guide is based on the TI 150 psi pressure sensor. Other sensors can be used however please check wiring and calibration data to suit the sensor.
About
Haltech Part HT-010904
An Oil Pressure Sensor is a sensor that can read up to around 150 to 250 psi of pressure and is resistant to fuel and oil. With oil pressure being monitored the ECU can be programmed to provide Engine Protection (selected Elite ECU models) whereby the engine can be placed into a safer state when oil pressure is considered to be at a level where engine damage may occur.
The sensors can be fragile and are not designed to be mounted directly in the engine block, instead they should be mounted somewhere insulated from engine block vibration. An extension hose is ideal for this purpose.
Wiring
Any spare AVI or SPI can be used for an Oil Pressure Sensor.
Configuration
Wiring
It is best to configure the wiring connection in your ECU first before physically wiring the sensor in. This ensures that only an input that can be used for Oil Pressure is used.
To enable an Oil Pressure Sensor:
1. Go to the Main Setup by clicking on the Gear icon at the top of the screen and then selecting Functions
2. Select Add/Remove Functions
3. Find the Oil Pressure Sensor (you can use the search for this) and move it to the right hand side and hit OK.
4. Oil Pressure Sensor will now be in your list of Functions. Click it to proceed with the configuration.
5. Select Edit Connection to pick an appropriate spare input. Only inputs that can be used will be in the list.
In this instance, AVI2 has been selected.
6. Ensure that the Pull Up is set to Disabled. This is because the sensor it already powered and does not need a pullup. Enabling the pullup can skew the readings.
7. Load or manually enter the Calibration data and hit OK.
Calibration
Engine Protection
For the purposes of this demonstration the Engine Protection configuration is shown for Elite 1500 and 2500 models.
Enabling Low Oil Pressure Detection
The detection of a low oil pressure condition is handled by going to the Oil Pressure Sensor function and then going to the Diagnostic tab.
From here the Operating condition should be ticked. Next you will select the DTC Severity Level of a low oil pressure condition. We normally consider this the most severe condition so Level 3 should be selected from the pull down list.
When this is complete you will find a new section called Oil System on the left hand side where all of your tables are located.
This is where you will be able to adjust the conditions that need to be met, and the oil pressure level below which Engine Protection should activate.
Configuring When Engine Protection Should Activate
We have two sections in the Oil System that need to be configured. The first is the DTC Settings section.
Here you will select the RPM over which a low oil pressure condition can trigger Engine Protection. Keep in mind that setting this at too low an RPM amount can cause engine protection to falsely trip when an engine first starts and oil has not circulated yet.
You can also select how long the oil pressure needs to be below the set amount to trigger protection under the DTC Delay setting, and how much engine load is being applied before it cal trigger protection as well.
Next is to set the actual oil pressure level to trigger Engine Protection. Set the Oil Pressure Minimum table to an appropriate value. Using the above settings, if we are over 2000rpm, and using 1% Throttle or more, and the oil pressure drops under the values in the table below then Engine Protection will activate.
The above table is only used as a guide, and you should set appropriate levels to suit your application.
Engine Protection Settings
After the detection of a low oil pressure condition has been set up, we now need to decide what to actually do about the situation. To be able to react we first need to enable Engine Protection as a Function. As with adding an Oil Pressure Sensor we also need to go to the Main Setup / Functions section and add Engine Protection to the list.
Next step is to enable all of the Severity Levels. We are more interested here in Level 3 which is listed as the Most Severe condition which is appropriate for having low oil pressure.
In this section we set what we want the ECU to do to prevent engine damage. In the above example we have told the ECU to run slightly richer by 0.2 AFR, we are turning off Boost Control by applying a -100% correction, we are retarding ignition timing by 5 degrees to take a little power away, and most importantly we are enabling a fuel cut at 1500 rpm. If a DBW throttle is present a maximum throttle value can be used to further limit how much power canbe developed.
Most people assume that the engine should be completely shut down when there is low oil pressure, however this can present other issues. If for example you are on a freeway where people are travelling at high speed, shutting the engine off can leave you in a very dangerous situation resulting in a possible car accident with injury or death a distinct possibility. Considering this, it is better to simply introduce a low RPM limit that allows the vehicle to be driven to the side of the road and when in a safe location the engine can be shut down.
The Active Condition setting controls whether a simple ECU power cycle off/on will clear the Engine Protection state (Current DTC's Only), or a laptop needs to be connected and the DTC manually cleared (Current and past DTCs).
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