What the sensor does for you
A power steering pump takes more power as the system pressure rises, and that happens most when you're parking or turning at low speed, which is exactly when the engine is idling and has the least torque to spare. A power steering pressure sensor gives the Elite a live reading of that pressure so it can bump the idle up before RPM sags. It also lets ESP warn you when pressure is outside the range you expect, and flag wiring faults with diagnostic codes.
If you only need to know whether the pump is working hard, not how hard, a simple on/off power steering switch may be all you need. A pressure sensor gives you a proper number to log and act on.
Wiring tab: choosing an input
The sensor needs an analog input. You have two choices:
| Input | When to use it | Pull-up option | Other settings |
|---|---|---|---|
| AVI (analog voltage input) | First choice for this sensor | 1k resistor to 5V | - |
| SPI (synchronized pulsed input) | When you've run out of AVIs | Weaker 10k resistor to 5V | Set Sensor Type to Hall Effect for any analog signal |
Should the pull-up be on?
Pull-ups are for sensors that can't make their own voltage, like two-wire temperature sensors. Those need the ECU to supply a reference through a resistor. A three-wire pressure sensor has its own 5V supply and ground and drives the signal wire itself, so for a typical pressure sensor the pull-up should be off. Leaving it on can shift the reading.
The other case where it should be off is a shared sensor. If the Haltech is reading a sensor that the factory ECU also reads, as in a piggyback install, the factory ECU normally already provides any pull-up that's needed.
Calibration tab
This is where you tell ESP how to turn the sensor's voltage into pressure. The default calibration is for the Haltech 150 psi pressure sensor, and ESP includes a set of other calibrations too. Use the open (folder) icon to load a calibration file and the save (disk) icon to store one you've built.
If your sensor isn't on the list, build a custom calibration from the manufacturer's voltage-to-pressure data. Whatever you use, confirm the calibration matches the sensor actually fitted. A sensor from a different range will still give smooth readings, they'll just be wrong. Haltech sensors like the 150 psi TI pressure sensor make this easy because the calibration is ready to go.
Display tab: warning limits
- Warning Minimum: if pressure drops below this, any power steering pressure gauges or indicators in ESP flash red. A sudden low reading can mean a failing pump, a leak or low fluid.
- Warning Maximum: if pressure goes above this, the same items flash red to warn of high pressure, for example the system sitting on its relief valve for too long.
These are visual warnings in the software. Set them from what you see in your own logs: log pressure at idle, at full lock and while driving, then set the limits just outside that normal range.
Diagnostics tab: catching wiring faults
Sensor faults usually show up as a voltage that a healthy sensor would never produce. A shorted signal tends to read near zero or near 5V, and an open circuit often floats to one end. The diagnostics tab lets you set voltage limits that define "impossible":
| Setting | Trips when | Code | Default |
|---|---|---|---|
| Raw Min | Sensor voltage falls below your limit | P0552 | Disabled |
| Raw Max | Sensor voltage rises above your limit | P0553 | Disabled |
If you're running the Elite's Engine Protection function, you can assign a DTC severity to each of these faults so the ECU responds the way you want.
Set Raw Min and Raw Max just outside the voltage range the sensor can produce in normal use, then unplug the sensor with the key on to confirm the fault actually triggers. It takes a minute and proves the diagnostic will work when you need it.
Troubleshooting
| Symptom | Usually |
|---|---|
| Reading pinned at max or min | Missing 5V supply or ground, or signal wire on the wrong input |
| Reading looks sensible but wrong | Wrong calibration loaded, or pull-up left on |
| P0552 or P0553 on a working sensor | Raw limits set too close to the sensor's normal range |
| Idle still dips at full lock | Sensor is fine. Check your idle control setup and idle-up settings |
FAQ
Does the power steering pressure sensor raise idle by itself?
The ECU uses the pressure reading to add idle when steering load rises. Check the result in your idle control setup, and remember other loads such as air conditioning that also call for extra idle.
Can I use an SPI if all my AVIs are taken?
Yes. Set the sensor type to Hall Effect and turn off the pull-up for a three-wire pressure sensor.
