Fault Codes/General Motors Powertrain/652General Motors Powertrain652UnclassifiedFuelWhat This Code MeansFuel Rev LimitPossible Causes•Mechanical operation fault in the throttle•Programmed governor speeds exceeding 3250 rpm•Very large air leaks below the throttleSuggested Actions1Check the engine for very large air leaks below the throttle2Check the mechanical operation of the throttle3Ensure that any programmed governor speeds do not exceed 3250 rpm4If any other DTCs are present, diagnose those firstRelated General Motors Powertrain Fault CodesDTC 412DTC 425633DTC 433556-RTI 3P0300515P0336514-RTI 1DTC 112DTC 122651Browse all General Motors Powertrain fault codes→ASK RUDY ABOUT THIS FAULTGet a diagnosis walkthrough for 652 on your specific General Motors Powertrain unit — cited to the OEM manual, not a forum guess.Your question about 652GET THE ANSWERFree account required — we'll bring your question with you.