The P2122 code on your 2021 Ram 1500 indicates a problem with the throttle/pedal position sensor D at minimum stop position. This code affects your Ram's 3.6L Pentastar V6, 5.7L HEMI V8, or 3.0L EcoDiesel engine's accelerator pedal position sensing system.
Understanding P2122 on Ram 1500
The accelerator pedal position sensor uses dual sensors (D and E circuits) for redundancy. Code P2122 sets when sensor D voltage at the minimum (foot off pedal) position is not within the expected range. This indicates the sensor may be out of calibration, damaged, or has a circuit issue affecting its resting voltage.
Common Symptoms
- Check engine light on
- Reduced engine power mode
- Erratic idle or throttle response
- Throttle may not respond from rest
- Hesitation when starting from stop
- Engine may race unexpectedly
- Cruise control disabled
Primary Causes
- Faulty accelerator pedal position sensor
- Sensor out of calibration or drifted
- Damaged wiring to accelerator pedal
- Corroded pedal sensor connector
- 5-volt reference circuit problem
- Ground circuit issue
- Floor mat interfering with pedal travel
Diagnostic Procedure for 2021 Ram 1500
Monitor APP sensor D voltage with foot completely off the pedal - compare to specification (typically 0.5-1.0V at minimum). Check if voltage changes when pedal is fully depressed. Compare sensor D readings to sensor E readings for correlation. Ensure no floor mats restrict pedal return to full rest position. Test 5-volt reference and ground at pedal connector. Inspect wiring for damage, especially under dash area.
Repair Solutions
Ensure floor mats don't prevent full pedal return. If APP sensor D voltage is out of specification at rest, replace the accelerator pedal assembly as sensors are integrated. Repair any damaged wiring or corroded connectors. Test 5-volt reference supply if multiple sensor codes are present. After replacement, clear codes and verify proper minimum stop voltage with foot off pedal.