What Does P0121 Mean on a 2023 Nissan Murano?
P0121 on your 2023 Nissan Murano reveals that the throttle position sensor (TPS) is transmitting voltage within the expected range but with a signal pattern the ECM considers abnormal. The computer detects a mismatch between TPS data and its calculations from pedal input, airflow, and load parameters.
The 2023 Murano—the final model year before discontinuation—continues with the 3.5L VQ35DE V6 (260 hp) and CVT. As the last model year, the platform is extremely well-refined. Port injection keeps the throttle body cleaner than DI engines.
Common Symptoms to Watch For
- Check engine light on
- Hesitation during acceleration
- Rough or fluctuating idle
- CVT feels unresponsive
- Reduced power when loaded
- Fuel economy slightly decreased
Top Causes Ranked by Likelihood
- Carbon buildup on throttle body (30%) – At 1-3 years, early deposits from PCV gases are possible with short-trip driving. Cost: $150–$300.
- Throttle body assembly defect (25%) – Internal TPS defect or quality issue. Cost: $0 under warranty.
- ECM software calibration (25%) – An available update. Cost: $0 under warranty.
- Wiring or connector issue (15%) – Corrosion or assembly variability. Cost: $0 under warranty.
- Intake system leak (5%) – A gasket or vacuum hose issue. Cost: $0 under warranty.
How Serious Is This Code?
P0121 is medium severity. Address this soon—your warranty likely covers it.
Diagnostic Path
Your 2023 Murano should be under warranty. Take it to a Nissan dealer for CONSULT diagnostics and TSB checks.
Can You Fix This Yourself?
Your 2023 Murano is within Nissan's 3yr/36k basic and 5yr/60k powertrain warranties. Take it to the dealer—free diagnosis and repair.
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