Throttle Position Sensor Disagreement btwn Sensors
Your engine has two throttle position sensors that should agree on how far open the throttle is, but they're sending conflicting signals—like two speedometers in your car showing different speeds. The ECU detects this mismatch and triggers a warning to prevent engine damage or poor performance.
The ECM monitors two redundant throttle position sensors (TPS1 and TPS2) and compares their voltage outputs as the throttle opens and closes. If the difference between sensor readings exceeds a calibrated threshold, the fault is triggered to ensure safe operation.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| TPS1 vs TPS2 Voltage Delta | < 0.1V difference at same throttle angle | > 0.15V divergence across operating range |
| Sensor Response Time | Synchronized within 10ms | Delayed or erratic response by one sensor |
Code P1579 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P1579 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.