Control Module HVAC: Service Precautions

General Repair Information

• Disconnect the battery before performing any electric welding on the vehicle.

Refrigerant circuit of A/C system must not be discharged and opened unless this is necessary because of safety precautions (=> [ Handling Refrigerant Safety Precautions ] Handling Refrigerant Safety Precautions) or unless components of the refrigerant circuit of the A/C system have to be to replaced.

When performing all other usual vehicle repair work, the refrigerant circuit of the A/C system should remain closed.

Work on refrigerant system should only be performed in a ventilated rooms (workshops). Ensure that with in 5 meters circumference are no working-pits, basement staircases or shafts. Turn on the existing ventilation systems.

Reason

The refrigerant emerging is not only colorless and odorless, but also heavier than air and thus displaces oxygen. If refrigerant gas does escape even though all the safety precautions have been followed, there is a risk of suffocating in poorly ventilated areas and in workshop pits - even if it is not noticeable.

• The escaping refrigerant/air mixture should not be inhaled, but should be extracted via an existing exhaust-extraction ventilation system.

Do not attempt repair on filled air conditioning systems by soldering, brazing or welding. This pertains also for welding and soldering work on the vehicle, in the event that parts of the climate control system may heat up

Reason

Exposure to heat creates considerable pressure in the system, which could cause it to burst.

Corrective Action

Discharge refrigerant circuit. Refer to => [ Refrigerant Circuit, Draining ] Refrigerant Circuit, Draining.

• Damaged or leaking parts of the air conditioner are never to be repaired by welding or soldering them. They must be replaced.

When servicing air conditioner, all open components and pipe connections are to be immediately re-sealed.

Reason

Moisture will enter into air conditioner components if they are left open for a lengthy period. If this is the case, air conditioners cannot be refilled without having to replace parts of the system.