Volkswagen Golf / Golf GTI / Jetta. Manual - part 1010

caused by inadequate bending 
radii. 

- Check refrigerant pipes and 
hoses for external damage. 

- If no fault is found, flush 
refrigerant circuit with compressed 
air and nitrogen. 

 

Pressure in refrigerant circuit in 
line with table or higher.

- Start engine. 

- Set air conditioning system to 
maximum cooling output. 

Note: 

- If the low pressure switch was 
removed to connect the service 
station, bridge the electrical 
connections in the corresponding 
connector for the pressure 
measurement. 

- A/C compressor is driven by the 
engine via A/C Clutch N25 . 

- A/C Compressor Regulator Valve 
N280 is activated by Climatronic 
Control Module J255 . 

 
 

 Repair Manual, Heating & Air 

Conditioning, Repair Group 87 , 

 

If compressor is not driven with 
engine running or regulating 
valve is not actuated:

- Establish and eliminate cause 
e.g. by checking air conditioner 
DTC memory. 

- Observe test conditions. 

- Check voltage supply for A/C 
Clutch N25 , if this is OK, repair 
A/C clutch. 

- Check activation of A/C 

Pressures, checking on vehicles

13/2/2005

Compressor Regulator Valve 
N280 . 

 
 

. 

 Repair Manual, Heating & Air 

Conditioning, Repair Group 87 , 

Continuation of pressure 
testing

 

- Checking pressures for vehicles 
with restrictor and reservoir (with 
internally regulated compressor) 

 

00-7, Restrictor and reservoir 

(with internally regulated 
compressor), checking

 . 

- Checking pressures for vehicles 
with expansion valve and receiver 
(with internally regulated 
compressor) 

 

00-7, Expansion 

valve and receiver (with internally 
regulated compressor), checking

 . 

- Checking pressures for vehicles 
with expansion valve and receiver 
(without internally regulated 
compressor) 

 

00-7, Expansion 

valve and receiver (without 
internally regulated compressor), 
checking

 . 

- Checking pressures for vehicles 
with restrictor, reservoir and A/C 
Compressor Regulator Valve 
N280 (externally regulated 
compressor) 

 

00-7, Restrictor, 

reservoir and A/C Compressor 
Regulator Valve N280 (externally 
regulated compressor), checking

 . 

Restrictor and reservoir 
(with internally regulated 
compressor), checking

 

Note: 

- Connect service station 

 

00-6, 

Service station, connecting

 . 

Pressures, checking on vehicles

13/2/2005

  

- Observe test conditions 

 

00-7, 

Pressures, checking on vehicles

 . 

- Set engine speed to 2000 RPM. 

- Observe pressure gauge of 
service station. 

Note: 

- Switching pressures for 
refrigerant circuit switches are 
vehicle-specific. 

- Connection with valve for low-
pressure switch or at evaporator is 
only to be used for vehicles with 
no service connection on low-
pressure side and an inaccessible 
connection at compressor or 
reservoir (measurement 
accuracy). Only applies to certain 
vehicles. 

 
 

 Repair Manual, Heating & Air 

Conditioning, Repair Group 87 , 

Specified values:

 

 

High pressure side:

 

Increasing from initial pressure (on 
connecting pressure gauges) to 
max. 20 bar.

 

Low pressure side:

 

Decreasing from initial pressure 
(on connecting pressure gauges) 
to value in graph.

A - High pressure (measured at 
service connection) in bar 

B - Low pressure (measured at 
connection with valve at 
compressor or reservoir) in bar. 

C - Permissible tolerance range. 

Pressures, checking on vehicles

13/2/2005

 

 

D - Low pressure (measured at 
connection with valve for low-
pressure switch or at service 
connection) in bar. 

E - Permissible tolerance range. 

Possible deviation from 

specification

Possible cause

Corrective action

- High pressure remains constant 
or only increases slightly (above 
pressure with engine stopped), 

- Low pressure quickly drops to 
value in graph or below, 

- Required cooling output is not 
attained. 

Not enough 
refrigerant in 
refrigerant circuit.

- Localize leak using leak detector 
and eliminate. 

- Re-charge refrigerant circuit. 

- High pressure normal, 

- Low pressure in line with value in 
graph, 

- Required cooling output is not 
attained. 

 

 

- High pressure normal, 

- Low pressure too low (see 
graph), 

- Required cooling output is not 
attained. 

 

 

Note: 

- If no malfunction is found in 
relation to this complaint, flush 
refrigerant circuit with compressed 
air and nitrogen. 

Possible deviation from 

specification

Possible cause

Corrective action

- High pressure only increases 
slightly above pressure with 
engine stopped, 

- Low pressure only drops slightly, 

- Required cooling output is not 
attained. 

A/C compressor 
malfunctioning.

- Flush refrigerant circuit with 
compressed air and nitrogen. 

- Replace compressor. 

- High pressure increases above 
specification

- Low pressure quickly drops to 
value in graph or below,

- Required cooling output is not 
attained.

Pressures, checking on vehicles

13/2/2005