This dashboard provides real-time visibility into the performance and health of the drive-by-wire (DBW) electronic throttle system, including pedal sensors, throttle body sensors, target position, PWM output, and system safety status.
Each circular gauge shows a specific real-time parameter involved in throttle control:
The Error code field is a 4-digit encoded string like:
A|B|C|D
Where:
A = Pedal 1 input errorB = Pedal 2 input errorC = TPS 1 input errorD = TPS 2 input errorEach digit can have one of the following values:
| Code | Meaning |
|---|---|
| 0 | No error |
| 1 | Short to ground (low voltage fault) |
| 2 | Short to V+ or not connected (open circuit or high voltage fault) |
| 3 | Out of range / exceeded safety margin (mismatch or failed redundancy) |
If the error code shows 0|2|0|3, this means:
This helps isolate wiring problems, sensor mismatches, and installation mistakes during tuning or diagnostics.
This screen provides low-level configuration and safety parameters for electronic throttle control, including PID tuning, position tolerances, current limiting, and calibration routines for both the pedal and throttle body.
| Parameter | Description |
|---|---|
| Minimum Position Deviation Tolerance | The smallest allowed difference (in %) between actual throttle position and target. If the actual position deviates below this margin, it may be flagged as a fault. |
| Maximum Position Deviation Tolerance | The maximum allowable deviation (in %) before triggering a throttle control error. Helps detect stuck or overshooting throttles. |
| Current Limiting (Enable / Amps) | When enabled, limits the maximum motor current to prevent overdriving the throttle actuator. Value shown (e.g., 6.0 A) defines the current limit. |
| Maximum Board Temperature | Defines a critical temperature limit for the control board. When exceeded, throttle control is reduced or disabled to protect electronics (e.g., 70°C). |
| Maximum Control for Idle | Limits the throttle opening allowed by idle control system to prevent over-revving. This prevents the idle control loop from fully opening the throttle during a misconfiguration or fault. |
This section controls the real-time PID loop that adjusts the throttle motor's behavior based on the error between actual and target position.
| Component | Function |
|---|---|
| P (Proportional) | Reacts proportionally to the error between actual and desired throttle position. Higher values = more aggressive correction. |
| I (Integral) | Accumulates past error over time. Helps eliminate long-term drift or residual error. High values can cause overshoot or oscillation if too aggressive. |
| D (Derivative) | Dampens rapid changes in error. Reduces overshoot by responding to the rate of change. Useful for stabilizing fast responses. |
⚠️ Tuning PID incorrectly may result in sluggish, oscillating, or unstable throttle behavior. Use
Autotuneor manual step tests when unsure.
This section ensures the ECU correctly interprets pedal and throttle positions.
| Item | Description |
|---|---|
| Firmware Version | Displays the currently loaded firmware version for the throttle controller. |
| Update Button | Launches firmware update procedure. Only use with a valid, verified firmware file to prevent bricking. |
The RM-Primis ECU supports flexible control of Electronic Throttle Bodies (ETBs) through a combination of:
| Use Cases |
|---|
| Maps driver pedal to throttle opening |
| Enables progressive response |
| Shapes torque delivery and traction |
Tab: Feed forward
Purpose: Adds PWM to both PID and Holding logic to:
ℹ️ This is the main error correction map. It works by preemptively adding PWM based on pedal and RPM context, not real-time error.
🧠 Important:
Changes in this table affect PID math. Always re-tune the PID after adjusting the Feed Forward values.
Purpose: Applies a baseline PWM signal to hold the throttle plate at specific positions, counteracting:
This is essential for stable idle, cruise, and low-vibration control.
Different electronic throttles behave differently when powered off. This changes how you must tune the holding PWM:
| Type | Behavior When Unpowered | Holding PWM Characteristics |
|---|---|---|
| Fully Closed | Spring forces throttle fully shut | Holding at 0% may require positive PWM to open, and very little or no PWM to stay closed |
| Semi-Open | Throttle rests around 5–15% open | Requires negative PWM to close, and positive PWM to open |
| Failsafe-Open (rare) | Stays wide open when off (usually older DBW) | Needs large negative PWM to close and hold |
If you're using a generic or undocumented ETB, follow this process:
Set PID gains to zero temporarily
Set Feed Forward table to 0
Open the Holding Table
Feed forward tab (left side panel)Observe Motor Current
Start with neutral (0 PWM) and adjust:
Repeat at multiple throttle angles
Save & Smooth
Re-enable PID and Feed Forward
| Throttle Position (%) | Holding PWM |
|---|---|
| 0 | -20.0 |
| 10 | -10.0 |
| 50 | +10.0 |
| 100 | +28.0 |
This is typical of a semi-open throttle that requires negative PWM to close and increasing PWM to hold open positions.
| Symptom | Possible Cause | Solution |
|---|---|---|
| Throttle buzzes/vibrates at idle | Holding PWM too high | Lower the PWM at 0–10% |
| Throttle drifts open at rest | Not enough holding force | Add negative PWM (for semi-open ETB) |
| High current draw at idle | Overdriven holding | Reduce PWM near idle positions |
| Throttle moves erratically under load | Feed Forward too aggressive | Reduce feed forward table in that zone |
| Oscillation after PID tune | Holding map mismatch with PID | Re-check holding and reduce PID gains |
| Table | Role | What it Affects |
|---|---|---|
| Target | Desired throttle angle (driver input) | PID position reference |
| Feed Forward | Adds speedup PWM to PID & Holding | Response sharpness, system damping |
| Holding | Maintains position under mechanical load | Stability at fixed throttle angles |