Automatic Climate Control System heating performance and operation of pump valve unit, testing: Testing
- Connect VAG 1551 Scan Tool. See VAG 1551 ((VAG 1552) SCAN TOOL (ST), CONNECTING AND SELECTING FUNCTIONS .
- Start engine and run at maximum cooling capacity for a few minutes (compressor is switched on, temperature selector at "LO" for left and right sides).
- Switch ignition off.
- Press "Rest" button (residual heating) on A/C control head - E87-
A/C control head -E87- operates, coolant pump -V50- does not run, right and left heat regulating valves -N175- and - N176- closed
NOTE: The time for the "Rest" function (residual heating) is limited by -E87- (to about 10 minutes). - Connect VAG 1551 and select Read measuring value block, function 08 (display group 014). See READ MEASURING VALUE BLOCK (FUNCTION 08) .
- Read off measured values of display fields 3 and 4.
Specification: ambient temperature plus not more than 15 °C (59° F)
- Set temperature selector for left side (on -E87-) to "HI".
Specified values:
- Temperature reading of display field 3 increases to approx. engine temperature
- Coolant pump -V50- running, valve -N175- open and valve -N176- closed
- Temperature reading of display field 4 remains approximately constant. Temperature increase less than 10° C (50° F) and valve -N176- closed.
- Set temperature selector for right side (at -E87-) to "HI".
Specified values:
- Temperature reading of display field 4 increases to approx. engine temperature.
- Coolant pump -V50- running, valves -N175- and -N176- open
- Set temperature selectors for left and right sides (at -E87-) to "LO".
Specified values:
- Temperature reading of display fields 3 and 4 drop within 5 minutes to ambient temperature, plus no more than 15° C (59° F).
- Coolant pump -V50- is not running, valves -N175- and - N176- are closed