P0020: owner reports and bulletins

Powertrain (generic, all makes). We haven't written the explanation for this code yet. Below is what owners and manufacturers have filed with NHTSA.

Got P0020 on your scanner? Tell the mechanic your year, make, model and any symptoms and you'll get the likely cause and what to check first. Ask about this code.

What owners report to NHTSA

3 complaints filed with NHTSA mention P0020, 3 of them since 2015, across 3 different models. The component owners most often filed it under: vehicle speed control.

Manufacturer service bulletins that name P0020

6 technical service bulletins and manufacturer communications filed with NHTSA mention P0020, from 4 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:

  • DODGE CHALLENGER (2023), bulletin 10248935: Cam Phaser Actuators Replacement Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation, the technician may find one or more of the following Diagnostic Trouble Codes (DTCs) …
  • CHRYSLER 300 (2023), bulletin 10248935: Cam Phaser Actuators Replacement Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation, the technician may find one or more of the following Diagnostic Trouble Codes (DTCs) …
  • JEEP GLADIATOR (2021), bulletin 10221660: 3.6L Check Engine Light and Rough Running Engine This bulletin involves cutting off a wiring harness eyelet and splicing in a pigtail to the engine ground harness. Customers may experience a Malfunction Indicator Lamp (M…
  • RAM 1500 (2021), bulletin 10221658: 3.6L Check Engine Light and Rough Running Engine This bulletin involves cutting off a wiring harness eyelet and splicing in a pigtail to the engine ground harness. Customers may experience a Malfunction Indicator Lamp (M…

Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.