ASM Mode Circuit Low
Your engine's Antilock/Stability Management (ASM) control circuit is reading a voltage that's too low, like a battery terminal that's loose and can't deliver proper power. The ECU can't properly control the ASM system because it's not receiving the correct electrical signal.
The ECM monitors the voltage supply and control signal to the ASM module circuit. When the voltage drops below the acceptable threshold, the ECU detects an insufficient power or signal condition and triggers the fault code. This prevents the system from operating safely.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| ASM Circuit Voltage | 9.0V to 14.5V | Below 6.0V or open circuit |
| ASM Control Signal | Proper PWM or digital signal present | Signal absent or below minimum threshold |
Code P0957 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, P0957 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.