Hydraulic Pump Relay Circuit Low
The ECU detected low voltage in the hydraulic pump relay circuit, meaning the electrical signal controlling the pump is too weak. It's like a dimmer switch that's stuck in the 'too low' position when it should be fully on.
The ECU monitors the voltage supplied to the hydraulic pump relay coil circuit. When the relay should activate, the ECU expects to see a specific voltage level (typically 12V). A low voltage reading indicates insufficient current flow, preventing proper relay engagement and hydraulic pump operation.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Relay coil voltage | 11-14V when activated | Below 10V or open circuit |
| Circuit resistance | Less than 5 ohms | Greater than 10 ohms or open |
Code P0947 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, P0947 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.