The P1680 diagnostic trouble code is a manufacturer-specific powertrain code. Its exact definition depends heavily on the vehicle make, pointing to an accelerator pedal sensor fault, a clutch switch circuit issue, or a metering oil pump malfunction.
Because this code targets entirely different systems across manufacturers, the exact vehicle application must be verified before diagnosis. The code alone does not prove a specific component has failed without proper testing.
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Key Takeaways
- P1680 is a manufacturer-specific powertrain code with differing definitions depending on the vehicle make.
- On GM applications, it indicates a Throttle Actuator Control System or Accelerator Pedal Position Sensor fault.
- On Chrysler, Dodge, and Jeep manual applications, it points to a Clutch Released Switch Circuit fault.
- On Mazda RX-8 applications, it indicates a Metering Oil Pump or Oil Control Valve circuit malfunction.
- Diagnosis requires verifying the exact factory definition and testing the relevant sensor, switch, or pump circuit.
P1680 Code Description and Implications
The P1680 code indicates that a control module has detected a specific fault within the throttle, clutch, or engine lubrication systems. Because it is a manufacturer-specific code, the exact monitored component varies significantly by brand.
Some GM applications (Chevrolet, GMC): P1680 indicates a Throttle Actuator Control System or Accelerator Pedal Position (APP) Sensor fault. The Powertrain Control Module (PCM) detects an implausible signal or circuit malfunction from the pedal assembly.
Certain Chrysler, Dodge, and Jeep applications: The code indicates a Clutch Released Switch Circuit Open or Shorted fault. The PCM detects an electrical issue in the circuit monitoring the clutch pedal position on manual transmission vehicles.
Some Mazda applications (RX-8): P1680 indicates a Metering Oil Pump (MOP) or Oil Control Valve circuit fault, meaning the PCM detects an electrical failure in the system that meters oil to the rotary engine apex seals.
Common Causes of the P1680 Code
Because P1680 applies to different systems across different brands, the root cause depends on the verified vehicle application.
GM Causes: A failing accelerator pedal position sensor, damaged wiring harness at the pedal assembly, poor electrical connections, or a failing throttle body actuator.
Chrysler/Dodge/Jeep Causes: A misadjusted or failing clutch pedal position switch, damaged wiring near the pedal pivot, or poor electrical grounds.
Mazda Causes: A failing metering oil pump, damaged wiring harness, poor electrical connections, or a faulty oil control valve solenoid.
Symptoms Associated With P1680
When the control module detects a critical system fault, it illuminates a warning light and may alter vehicle operation.
Warning Lights: The Check Engine Light will illuminate. On GM applications, a Reduced Engine Power or limp mode warning is likely.
Drivability: On GM applications, the vehicle may enter a severe limp mode with no throttle response. On manual Chrysler applications, cruise control may not engage or the engine may not crank.
On Mazda applications, driving with a failed metering oil pump can cause rapid engine destruction due to lack of apex seal lubrication.
Diagnosing the P1680 Trouble Code
Accurate diagnosis begins by verifying the exact vehicle application and reviewing manufacturer-specific service information.
For GM applications: Inspect the accelerator pedal assembly and wiring. Verify the applicable reference voltage, signal, and ground circuits according to the manufacturer procedure. Monitor live APP sensor data for dropouts or correlation errors.
For Chrysler/Dodge/Jeep applications: Inspect the clutch switch adjustment and wiring. Test the switch for proper continuity changes as the pedal is depressed and released.
For Mazda applications: Inspect the metering oil pump wiring and connectors. Test the pump motor and oil control valve circuits for opens, shorts, or excessive resistance.
Repairing the P1680 Issue
Repairs must follow the confirmed root cause identified during diagnosis.
Sensor and Switch Repairs: If the accelerator pedal assembly or clutch switch fails electrical testing, replace the confirmed failed component and clear the codes.
Pump and Circuit Repairs: If the metering oil pump or oil control valve fails testing on Mazda applications, replace the confirmed failed component immediately to prevent catastrophic engine damage.
Cost Considerations for P1680 Repairs
Cost depends on diagnostic time, component accessibility, required parts, programming requirements, and labor.
Replacing a clutch switch involves minimal labor. However, replacing an electronic accelerator pedal assembly or a metering oil pump requires moderate labor and potential module reprogramming.
Prevention Strategies for Future Occurrences
Inspecting the wiring harness near moving pedals for chafing or damage helps prevent intermittent circuit faults on GM and Chrysler applications.
Maintaining the correct oil level and using the specified oil viscosity helps ensure the metering oil pump operates correctly on rotary engine applications.
Troubleshooting Tips and Best Practices
Follow these practices to avoid misdiagnosis and ensure accurate repairs.
Do not assume the PCM has failed just because a throttle or memory code is present: A damaged wire at the accelerator pedal hinge is a frequent cause of APP sensor faults. Always verify the wiring harness first.
Check for related codes: Look for accompanying throttle position or clutch switch codes, which might help pinpoint a broader sensor correlation issue.
Verify your definition: Always confirm whether your specific vehicle uses the APP sensor, clutch switch, or oil pump definition before ordering parts.
More OBD-II Codes
| P1674 | P1675 | P1676 | P1677 |
| P1678 | P1679 | P1681 | P1682 |
| P1683 | P1684 | P1685 | P1686 |
| P2101 | P0220 | P0121 | P0704 |
| P0705 | P0601 | P0603 | P0604 |
| P0605 | P0606 | P0505 | P0520 |
Frequently Asked Questions
Is P1680 a generic or manufacturer-specific code?
No. P1680 is a manufacturer-specific powertrain code. Its definition varies significantly by brand, indicating an accelerator pedal sensor fault, a clutch switch issue, or an oil pump malfunction.
Can I drive my vehicle with a P1680 code?
On GM applications, the vehicle will likely enter a severe limp mode. On Mazda applications, driving with a failed metering oil pump will cause rapid engine destruction. Driving should be avoided until repaired.
Will disconnecting the battery clear the P1680 code?
Disconnecting the battery might temporarily clear the code. However, it does not repair the underlying failing sensor, damaged pedal wiring, or broken oil pump, and the code will return upon the next monitor cycle.
Can a bad clutch switch cause a P1680 code?
Yes. On manual transmission Chrysler, Dodge, or Jeep applications, a misadjusted or failing clutch pedal position switch can cause an open or short circuit condition, triggering the P1680 code and preventing cruise control operation.
Does P1680 affect the transmission?
On manual applications, a faulty clutch switch can prevent the engine from cranking or disable cruise control. On automatic GM applications, the reduced engine power limp mode severely limits overall vehicle performance and acceleration.
What Should You Do About the P1680 Code?
When a P1680 code appears, confirm the exact factory definition for your specific vehicle make and model. Because this code targets entirely different throttle, clutch, and engine lubrication systems depending on the manufacturer, applying the wrong diagnostic path will lead to misdiagnosis.
Follow the applicable manufacturer diagnostic procedure to test the relevant system and components. Once the root cause is confirmed, complete the necessary electrical repairs, component replacements, or circuit corrections before returning the vehicle to normal service.
