What Does P1684 Mean?
The metering oil pump position sensor has detected a circuit malfunction. This sensor monitors oil injection pump position in rotary engines or specific oil metering systems to ensure proper lubrication.
Safety Warning
Critical for rotary engines - inadequate oil injection can cause severe engine damage. Do not operate engine extensively until repaired to prevent catastrophic failure.
Common Causes
40%
Failed metering oil pump position sensor with internal circuit fault
25%
Damaged or corroded wiring harness between sensor and ECM
20%
Metering oil pump mechanical failure preventing sensor from tracking position
10%
Loose or corroded sensor connector with poor electrical contact
5%
ECM sensor circuit failure or voltage reference problem
Diagnostic Steps
1
Step 1: Locate metering oil pump position sensor and inspect connector for corrosion or damage
2
Step 2: Measure sensor reference voltage and ground at sensor connector (typically 5V reference)
3
Step 3: Test sensor signal voltage while manually rotating pump or during engine operation
4
Step 4: Check wiring continuity between sensor and ECM for all circuits (signal, reference, ground)
5
Step 5: Verify metering oil pump operates freely and sensor can track movement without binding
Estimated Repair Cost
$200 - $800
Parts + labor, varies by vehicle and location
The metering oil pump position sensor has detected a circuit malfunction. This sensor monitors oil injection pump position in rotary engines or specific oil metering systems to ensure proper lubrication.
The most common cause of P1684 (Metering Oil Pump Position Sensor Circuit Malfunction) is: Failed metering oil pump position sensor with internal circuit fault
Typical repair costs for P1684 range from $200 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Critical for rotary engines - inadequate oil injection can cause severe engine damage. Do not operate engine extensively until repaired to prevent catastrophic failure.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1684 to identify the root cause.
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Quick Info
Category
Powertrain
System
Engine Lubrication / Oil Metering System
Difficulty
Type
Manufacturer
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