Metering Oil Pump Stepping Motor Circuit Malfunction
The engine's metering oil pump stepping motor isn't responding correctly to the ECU's commands, like a fuel injector that won't open when told. This affects the precise oil delivery timing in diesel engines with variable valve timing systems.
The ECU sends electrical pulses to the stepping motor to control metering oil pump position, which regulates fuel injection timing. It monitors motor coil resistance, step response timing, and feedback signals to ensure proper positioning within acceptable electrical and mechanical parameters.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Motor Coil Resistance | 4-8 ohms per coil | Open circuit (>15 ohms) or short (<2 ohms) |
| Step Response Time | 50-200 milliseconds | No response or >500 milliseconds delay |
Code P1693 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, P1693 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.