P2135 on Nissan vehicles typically means the Throttle Position Sensor (TPS) data does not correlate properly with the pedal position sensor data. The quickest path to fix is to inspect and replace faulty sensors or their wiring, then clear the code and test drive to confirm the issue is resolved.
What P2135 Means for Nissan
The P2135 code is defined as Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation. It means the engine control module (ECM) detected a disagreement between the throttle position sensor readings and the pedal position sensor readings that exceed its expected tolerance. This can trigger poor throttle response, limp mode, reduced power, or inconsistent idle. In Nissan models, this can involve the throttle body sensor assembly (TPS) and/or the pedal position sensor, and may be influenced by wiring or the ECU software. The issue is almost always electrical rather than purely mechanical at the engine side.
Common Causes
Below is a list of the most frequent contributors to a P2135 on Nissan vehicles. Review them in order and address any you find.
- Faulty throttle position sensor (TPS) or pedal position sensor (PPS) within their range or with erratic output.
- Damaged, frayed, or corroded wiring harnesses or connectors to the TPS/PPS or to the ECU.
- Loose, bent, or damaged connectors at the TPS, PPS, or ECU grounds.
- Grounding or power supply issues to the sensors or the ECU.
- Throttle body or pedal assembly mechanical binding or sticking that prevents accurate sensor readings from tracking each other.
- ECU software calibration needs or a known TSB/reflash for the model if applicable.
Addressing these causes typically resolves the code. If several items are out of spec, fix the simplest or most likely failure first and recheck.
Diagnostic Steps
Use these steps to verify the cause and avoid unnecessary part replacements. A careful diagnosis saves time and money.
- Verify the DTC with an OBD-II scanner and review freeze-frame data to see the conditions when the code was set. Note whether other sensor codes appear.
- Perform a visual inspection of the wiring and connectors to the TPS, pedal sensor, and ECU. Look for damaged insulation, pin corrosion, or loose connectors. Re-seat or replace as needed.
- Check throttle body operation. Ensure the throttle plate opens smoothly and returns to idle without sticking. Clean any dirt or carbon buildup if needed, but avoid damaging the sensitive sensors.
- Test sensor outputs with a multimeter or scan-tool live data. Compare the TPS and PPS voltages across the throttle range (idle to wide-open throttle). Typical TPS and PPS signals are 0.5–1.0 V at idle and 4.5–5.0 V at full throttle, with both sensors tracking each other within a small tolerance (check your model’s service specs). If the A/B channels diverge beyond tolerance, suspect a sensor or wiring fault.
- Inspect grounds and power feeds to the sensors and ECU. A weak ground or fluctuating supply can cause false correlation readings.
- Consider the possibility of a software issue. Some Nissan models require a dealer-level reflash or throttle-body relearn procedure after sensor replacement. Check service notes for your year/model.
Testing should lead you to one or two probable failure points. If you cannot reproduce correlation during live data or the readings remain inconsistent, proceed to component replacement and re-learn as required.
Repair or Replacement Steps
Once you have identified the faulty component, follow these steps to repair or replace it. Use OEM or manufacturer-recommended parts and procedures.
- Replace the faulty throttle position sensor (TPS) if confirmed defective, and use the correct part for your Nissan model. Ensure the sensor is installed with proper torque and connector seating.
- Replace the pedal position sensor (PPS) if it shows consistent misreadings or cannot be calibrated. This is common on drive-by-wire systems or older pedal assemblies.
- Repair or replace damaged wiring harness or connectors to the TPS/PPS/ECU. Use proper crimping repairs, heat shrink, or replacement connectors as needed. Re-seat all connectors firmly.
- Recheck the throttle body mechanicals and clean as needed. Confirm there is no binding and that the idle stop is properly set after work. If a throttle relearn is required by the service manual, perform it using the correct procedure.
- Clear the DTCs with the scan tool and perform a test drive. Observe live data to ensure TPS and PPS values track together smoothly through the full range of throttle.
After completing repairs, you should re-check with an OBD-II scanner and perform a drive cycle to confirm the P2135 code does not return. If it does, re-evaluate for alternate causes or consider ECU service options with a qualified technician.
When to Seek Help
If you are not comfortable performing electrical diagnostics, or if the vehicle exhibits poor drivability, reduced power, or engine limp mode, contact a certified Nissan technician. Some models require dealer-level tooling for a full TPS/PPS relearn and ECU calibration.
Summary
P2135 indicates a voltage correlation problem between the throttle position sensor and pedal position sensor. Most fixes involve testing and replacing faulty sensors, repairing wiring or connectors, and performing any required relearns. After repairs, clear codes and perform a thorough road test to confirm the issue is resolved. When in doubt, seek professional help to ensure proper calibration and vehicle safety.