What the MAP sensor does
A manifold absolute pressure (MAP) sensor reads the pressure inside the intake manifold, from deep vacuum at idle through to full boost. On an Elite running speed density, that reading is usually the primary load input for fuel and ignition, so its accuracy flows straight through to your tune.
External MAP sensors are powered devices, normally with three wires: a 5V supply from the ECU, a signal wire back to an input, and a signal ground.
Internal or external?
The first choice on the Wiring tab is Input Type:
- On-board Pressure Sensor (the default): uses the 3.0 bar sensor inside the Elite. Run a vacuum line from the manifold to the ECU's port and you're done. It's the easy option for naturally aspirated engines and mild boost. See Internal MAP Sensor for plumbing tips.
- Analogue Voltage: choose this when you're wiring in an external sensor. You'll need it once boost exceeds what a 3 bar sensor can read, or when the ECU is mounted far from the engine and a long vacuum hose would slow the reading down. Popular choices include the 3 bar motorsport, 5 bar TI and 7 bar TI sensors.
Choosing the input
With an external sensor, pick the input under Manifold Pressure Input. The default is AVI-9, but any suitable input works.
| Setting | What it does | Our advice |
|---|---|---|
| Connection type: AVI | Reads the sensor on an analogue voltage input | First choice for any MAP sensor |
| AVI pull up | Switches in a 1k resistor to 5V | Off. A powered MAP sensor drives its own signal; pull-ups are for two-wire temperature sensors |
| Connection type: SPI | Reads the sensor on a synchronized pulsed input | Only when you've run out of AVIs |
| SPI sensor type | Tells the SPI how to treat the signal | Set to Hall Effect for any analogue sensor on an SPI |
| SPI pull up | Switches in a weak 10k resistor to 5V | Off for a powered MAP sensor |
If the MAP sensor is also connected to another ECU, as in a piggyback setup, that ECU usually supplies any pull-up already. Leave the Elite's pull-up disabled so the two don't fight over the signal.
Display tab
These settings only change how gauges show the reading in ESP. They don't touch the sensor measurement or the tune.
- Warning Maximum: any gauge showing manifold pressure flashes red above this value. We set it just above the highest boost the engine should ever see, so a spike is obvious in a log review.
- Display Minimum and Display Maximum: the range of the gauge sweep. Set them to cover your real operating range so the needle uses the whole dial.
Calibration tab
This tab is only active with Input Type set to Analogue Voltage. ESP comes with calibrations for many common sensors; load one with the yellow open-folder icon. If your sensor isn't listed, build a custom calibration from the manufacturer's voltage-to-pressure data and save it with the blue disk icon so you can reuse it.
A quick sanity check we always do: with the engine off, the MAP reading should match current barometric pressure, roughly 14.7 psi (101 kPa) at sea level and lower at altitude. If it doesn't, the calibration or wiring is wrong. Compare against your barometric pressure sensor if you have one.
Diagnostics tab
Diagnostics let the Elite flag a failed sensor or a dangerous pressure. Each one is off by default. If Engine Protection is active, you can assign a DTC severity to each so the ECU responds, not just records a code.
| Setting | Code | What trips it | Our advice |
|---|---|---|---|
| Raw Min | P0107 | Sensor voltage below your limit (external sensor only) | Enable, set just under the sensor's lowest normal voltage to catch an open or shorted signal |
| Raw Max | P0108 | Sensor voltage above your limit (external sensor only) | Enable, set just over the highest normal voltage to catch a short to 5V |
| Operating Min | P0105 | Manifold pressure below your limit | Useful for spotting a sensor stuck low |
| Operating Max | P0106 | Manifold pressure above your limit | Set above target boost as an overboost warning, with a severity that suits the engine |
Troubleshooting
| Symptom | Usually |
|---|---|
| Reading doesn't match baro with the engine off | Wrong calibration loaded, or pull-up turned on |
| Reading pinned at max or min | Open signal wire, missing 5V, or a short |
| Noisy, jumpy reading at idle | Sensor tapped into a single runner, or a long, soft vacuum hose |
| Reads fine in vacuum, flat-lines in boost | Sensor range too small for the boost level |
FAQ
Is the Elite's internal MAP sensor good enough?
For naturally aspirated and moderate boost builds, yes. A 3 bar sensor reads up to about 43 psi absolute, which is roughly 28 psi of boost at sea level. Past that, or with a remote-mounted ECU, go external.
Where should the MAP sensor pick up pressure?
From the plenum, after the throttle, where the pressure is an average of all cylinders. Avoid single runners and the charge pipe before the throttle.
