The 2020 Dodge Charger's P0122 code indicates the TPS circuit voltage is lower than expected. This causes the ECU to interpret throttle position as near-closed, potentially affecting acceleration response and causing performance issues.
What P0122 Means
P0122 indicates TPS voltage is below minimum threshold. The TPS outputs increasing voltage as the throttle opens—typically 0.5V closed to 4.5V wide open. If voltage drops below approximately 0.3-0.4V or fails to rise properly, P0122 sets.
Charger Engine Options
The 2020 Charger offers multiple engines from the 3.6L Pentastar V6 to the supercharged 6.2L Hellcat. All use electronic throttle control. The TPS is critical for translating driver input into throttle position—low readings mean the engine can't accurately respond to acceleration commands.
Common Causes of Low TPS Signal
A failing TPS sensor can output lower than normal voltage, especially as the potentiometer track wears. Certain areas may develop high resistance, causing voltage drops.
Wiring issues including corroded connectors, damaged wires, or poor grounds cause voltage loss in the circuit. The signal may not fully reach the ECU.
Reference voltage problems—if the 5V reference from the ECU is low—cause proportionally low TPS output. Check that reference voltage is actually 5V.
Diagnostic Approach
Monitor TPS voltage at closed throttle (should be approximately 0.5V) and slowly increase to wide open (should reach approximately 4.5V). If voltage is abnormally low throughout the range or fails to increase properly, check the sensor. Verify 5V reference voltage at the TPS connector. Check for resistance in the ground circuit.