P1693 Metering Oil Pump Stepper Motor Circuit
Code P1693 indicates a malfunction in the metering oil pump stepper motor circuit, a component unique to Mazda's rotary engines (RX-8, RX-7 with Renesis or 13B-REW). This stepper motor controls the amount of oil injected into the combustion chambers to lubricate the rotor apex seals. The PCM detects an electrical anomaly—such as an out-of-range signal, open circuit, or short circuit—in the stepper motor circuit.
01. Most Common Causes
- Damaged wiring or poor connection in the stepper motor circuit
- Short to ground or voltage in the stepper motor harness
- Internal failure of the metering oil pump module
- Faulty PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Possible engine misfire or rough idle
- Increased engine wear due to inadequate apex seal lubrication
- Reduced engine performance or hesitation
03. Step-by-Step Diagnosis
Scan for additional codes and verify P1693 is present
Visually inspect the metering oil pump stepper motor connector and wiring for damage or corrosion
Test the stepper motor resistance and compare to manufacturer specifications
Check for shorts to ground or voltage in the circuit using a multimeter
If wiring and motor test OK, suspect the PCM or metering oil pump module
1. Frequently Asked Questions
Is it safe to drive?▼
No, driving with this code is not recommended. The metering oil pump is critical for apex seal lubrication; failure can lead to severe engine damage.
How much does it cost to fix?▼
Repair costs typically range from $200 to $800, depending on whether the stepper motor, wiring, or PCM needs replacement. Labor is moderate due to component accessibility.