ASM Control Circuit Range/Performance
The ECU detects that the Accelerometer Sensor Module (ASM) signal is outside its expected operating range or not performing correctly. Think of it like a speedometer that's giving readings that don't match how fast the car is actually going.
The ECU monitors the Accelerometer Sensor Module's voltage output and signal consistency to verify proper throttle input correlation. The sensor should produce a voltage signal that increases linearly with pedal position and falls within 0.5V to 4.5V under normal conditions. Out-of-range or noisy signals trigger this fault code.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| ASM Voltage Output | 0.5V to 4.5V, linear with throttle position | Below 0.5V or above 4.5V, erratic fluctuation |
| Signal Consistency | Smooth, predictable signal matching pedal input | Noise, dropouts, or non-correlation with pedal movement |
Code P0951 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, P0951 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.