Scantool Climate Control Unit question
10-26-2016, 01:07 PM
#16
Technical Guru
Rennlist Member
Rennlist Member
07-26-2019, 01:34 PM
#17
I have the BergvillFx cable and latest ScanTool software. When I connect the tool and toggle to the Climate Control menu - with the car running and climate control on - the climate control shuts off. If I toggle back to the Motronic menu - the climate control starts back up. The actual values pop-up shows no values while in Climate Control (it does in Motronic) - zero across the board. My car is a 1995 OBD1 w/ the OBD2 style connector. My issues are related to A/C which stopped working a couple weeks ago. I've went thru all the steps on Tore's sites and found both my fan resistors were shot. They have been replaced. I still didn't have A/C so I had the system purged, put under vacuum, leak tested, and re-filled with R134 and oil. No issues w/ the compressor nor freon levels but the compressor would only kick on for a few seconds and then stop for 15-20 seconds before kicking on again. I've also been checking the evap sensor with the readings between pins G18 and G22. What is odd - G18 does not appear to be a ground at all. Is it only grounded once plugged into the CCU? I've ordered a new sensor - should be here next week. I've now plugged the CCU back in...and I seem to have A/C again although I'm not sure it's as cold as it should be (differing opinions how good the 993 A/C is!).
Seems really odd that my HVAC shuts down and I get no actual values while in the climate control menu of the scan tool. Any idea what problem this may indicate? I'll send the CCU out for rebuild but I want to be sure that's the problem and I'm not finding any posts with a similar issue.
Seems really odd that my HVAC shuts down and I get no actual values while in the climate control menu of the scan tool. Any idea what problem this may indicate? I'll send the CCU out for rebuild but I want to be sure that's the problem and I'm not finding any posts with a similar issue.
07-27-2019, 04:45 AM
#18
Rennlist Member
-The CCU shuts off all outputs while active in a diagnostic session.
-In normal operation in 20 degrees ambient temp, the A/C compressor normally runs in 10-20 second intervals. If not, the evaporator would freeze over and be destroyed.
-The Porsche 993/964 A/C air temperature specification is shown in the Workshop Manual, and the temp chart is shown on this web page. The short version is that the system shall blow air at 7 to 9°C at 20°C ambient temperatures. Test in shade, windows shut, min temp, full fan, resirc on, and let run in about 10 minutes.
-G18 Sensor GND is tied to GND internally in the CCU. Your text does not describe any need for changing the evaporator sensor.
-The Scantool software is not compatible with all on-board control unit versions, especially in the 993. It will therefore not display the Actual Values, as well as not support the Drive Links actuator activation in a very good way.
Cheers,
Tore
-In normal operation in 20 degrees ambient temp, the A/C compressor normally runs in 10-20 second intervals. If not, the evaporator would freeze over and be destroyed.
-The Porsche 993/964 A/C air temperature specification is shown in the Workshop Manual, and the temp chart is shown on this web page. The short version is that the system shall blow air at 7 to 9°C at 20°C ambient temperatures. Test in shade, windows shut, min temp, full fan, resirc on, and let run in about 10 minutes.
-G18 Sensor GND is tied to GND internally in the CCU. Your text does not describe any need for changing the evaporator sensor.
-The Scantool software is not compatible with all on-board control unit versions, especially in the 993. It will therefore not display the Actual Values, as well as not support the Drive Links actuator activation in a very good way.
Cheers,
Tore