Code 61 - A/C System Performance (5.7L "F" Body): Notes

A/C refrigerant charge is calculated by inputs from the A/C refrigerant pressure and A/C evaporator temperature sensors. ECM will calculate system charge when the A/C is turned on. A/C evaporator temperature and A/C refrigerant temperature are factored together to yield a minimum charge allowable for the A/C system to operate. If system charge falls below a given value for the temperature and vehicle speed variables, Code 61 will set and A/C clutch will be disabled; however, SERVICE ENGINE SOON light will not turn on.

1. Code 61 could be caused by other codes. If other codes exist, use those charts first.
2. If the A/C refrigerant pressure sensor is "slewed" (out of calibration), the ECM could be detecting a lower than normal pressure and would set Code 61.
3. The conditions to set a Code 67 would cause Code 61 to set. Code 67 will set if the ECM does not detect an A/C refrigerant pressure change of more than 4 psi when the A/C clutch is cycled from off to on.