This screen allows configuring and calibrating the Air-Fuel Ratio (AFR) sensor input used by the RM-Primis ECU for:
The RM-Primis ECU supports both:
Select
Internalin the sensor input dropdown when using the onboard controller with an LSU 4.9.
If using a 3rd-party wideband controller (e.g., AEM, Innovate, 14Point7):
InternalExample: AEM UEGO may output 0.5V = 10.0 AFR, 4.5V = 20.0 AFR (you can use Quick Cal for this)
This table defines how input voltage is translated into AFR:
| Voltage (V) | AFR |
|---|---|
| 3.715 | 10.29 |
| 2.145 | 14.55 |
| 0.066 | 25.00 |
Displays live readings from the AFR input:
The ECU uses a PID controller to regulate the wideband sensor’s internal heater. Proper sensor temperature is essential for:
| PID Term | Description |
|---|---|
| P | Proportional – main heat response factor |
| I | Integral – maintains steady temperature |
| D | Derivative – reduces overshoot/oscillation |
Click Trend PID to watch heater response curves and tune PID sliders accordingly.
| Setting | Recommended Value |
|---|---|
| Target | 780°C |
| Minimum | 750°C |
| Maximum | 850°C |
Values outside this range may cause inaccurate readings or damage the sensor. Heater should stabilize close to the target within ~30 seconds of engine start.
| Symptom | Likely Cause | Solution |
|---|---|---|
| AFR stuck at 58.80 or 25.00 | Sensor cold or disconnected | Warm up sensor, check wiring or PID control |
| Heater bar stays empty | PID settings incorrect | Adjust P/I/D values or verify 12V feed |
| AFR fluctuates or is noisy | Poor grounding, voltage noise | Use shielded cable or relocate analog ground |
| AFR off by several points | Incorrect voltage vs AFR table | Use Quick Cal or input correct external data |
| Feature | Internal LSU 4.9 | External Wideband (0–5V) |
|---|---|---|
| Requires Heater PID | ✅ Yes | ❌ External handles it |
| Uses Voltage Table | ✅ Yes (Quick Cal or custom) | ✅ Must be calibrated manually |
| Preferred Setup | ✅ Yes – most accurate | Optional |
| Compatible Controllers | N/A (built-in) | AEM, 14Point7, Innovate, etc. |