Code 71 & 76 for the HVAC help

Have someone hook up a gauge set and see what the A/C system pressures are. Service manual said that pressures that are too high or too low can set DTC 76.

I believe that in normal operation, the radiator / condenser fans will only activate if A/C high side pressure goes above a certain point, or if engine coolant temperature goes above a setpoint.

If you run the engine long enough (perhaps if you put the car in maintenance mode? -use the search function on this forum to learn about that), -do the radiator fans come on?

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Here's a post with details on how the fans are controlled.

Conditions are normally one of: (1) both fans off, (2) both fans low speed, (3) both fans high speed.

They should never be in both-fans-off state any time the A/C is in use. The A/C itself will put them in both-low state, unless there is already some other reason to be in both-high state.

If the high-side pressure goes above a certain point, that triggers escalation to the both-high state.