Checking Audi TT 8N

Checking

1. Start engine.
2. Switch compressor on (select AUTO mode).

If the compressor is activated

1. Disconnect harness connector -B- from switch.
2. A/C Compressor will stop (low pressure switch open).
3. Remove switch -A- and install harness connector -B-.

A/C Compressor will not be activated (low pressure switch open).

If the compressor is not activated

1. Disconnect harness connector -B- from switch -A- and bridge terminals -1- and -2- on harness connector -B-.

The compressor will be activated.

Note. If the compressor is activated when the terminals are connected together, refrigerant system pressure is low or system is empty (check refrigerant system pressures. Refer to A/C refrigerant system pressures, checking ), or the switch is malfunctioning. If the compressor is not activated and the measuring value block display indicates A/C pressure switch -F129- as the cut-off condition, there is an open circuit in the wiring between A/C pressure switch -F129- and A/C control head -E87-. Trace and repair open circuit after performing electrical test. Refer to A/C Control Head -E87-, electrical testing .

Scheme 14

1. Disconnect electrical connection.
2. Remove high pressure sensor -B-.

Tightening torque: 5 Nm (44 in. lb)

1. Replace O-ring seal -A- (10.8 mm x 1.8 mm). Refer to «O-rings»(/audi/tt/8n-1998-2003/remont/ac-compressor/#heating-air-conditioning) .

Note. A/C cooling efficiency cannot be checked with -G65- removed or disconnected. Coolant Fan Control (FC) Module -J293- will not energize A/C clutch -N25-. Refrigerant system remains closed due to Schrader valve under sensor in line connection. Checking signal. Refer to High pressure sensor -G65- signal, checking . Checking refrigerant system pressures. Refer to A/C refrigerant system pressures, checking