Hello All,
just wondering if anyone has seen an issue like this before..
we have a 2008 Audi A3 (8P) which came in initially for non working Aircon issue.
The system needed recharging so it was purged, leak tested (and appeared to be leak free) and recharged.
This car has the manual temp control "Climatic" system. When tested first, the compressor appeared to come on (LED lit on A/C button and compressor could be heard loading the engine) but within 20 or 30 seconds, the refrigerant pressure on both the measuring blocks live data and the A/C service unit high side pressure gauge went up to over 25 bar, well outside of the normal operating range. The A/C was turned off before the pressure went any higher.
We noticed that the cooling fans failed to spin up as the pressure built, which would explain why the pressure went so high. Its possible this was responsible for the initial loss of refrigerant, as the excessive pressure possibly opened a relief valve.
On one subsequent test, the system appeared to work normally, and this time we were watching the live data on the climatic unit via VCDS. The cooling fans were coming on, and the compressor regulation current was varying from its maximum of around 750 mA at the start, back to around 500 mA as the pressure built up, and kept changing, meanwhile the high pressure stabilised below 20 bar, the cooling fans were running and the vents were blowing cold air and the A/C seemed to be functioning as expected.
but after stopping and going for tea, we tested again and again this time, the pressure kept increasing, the fans never came on and again we had to shut off the A/C before something gave. We noticed that the compressor regulating current stayed at 750 mA, and what looked like the "cooling fan" speed value stayed at 10%. It seemed as if the system is not responding to the G65 high pressure signal. Every subsequent test had the same result.
On the engine ECU, the cooling fans respond perfectly to the output test every time. So we know the fans are working.
One issue we had was VCDS has no label file for this particular climatic control unit (8P0-820-047-D). the above measuring blocks I've mentioned were fairly obvious from their "probable" labels in VCDS. however we checked with another scan tool and found a parameter for "requested fan speed" also. looking at this value and repeating the test, we found that the requested fan speed value was actually rising up to a maximum of 90% as the pressure begins to climb. however the parameter "actual fan speed" stayed at 10%.
There are no fault codes in either the climatic unit or the engine controller, and we know the G65 refrigerant pressure sender is good as the measuring block reading matches the actual gauge reading on the service station. looking at a label file for a golf V climatic controller, the measuring blocks look very similar, so with the parameters from the other scan tool and the other label file, we can be reasonably confident we have the correct values.
So it seems as if the climatic controller is requesting the fan speed be increased, yet the Engine ECU is not doing as requested. furthermore, the compressor is being kept at full output. The compressor shut-off condition value goes to 0 when the A/C is turned on, and never changes either.
the full auto scan shows no other real issues, there is a control module fault in the instruments but this seems to have been there for some time before this fault. no communication errors. And the G65 and other A/C info is showing up in the engine controller, so we know the climatic and Engine controller are "talking". The radio fault codes are due to the radio having been removed at the time to allow access to the climatic unit.
we also disconnected and reconnected the battery in case of any silly software "lockups" but no difference.
Then in the absence of any other obvious problems, we obtained another climatic unit which has a later software version but this failed to resolve the issue.
full auto scan below.
Any Ideas to solve this mystery greatly appreciated..
thanks for reading..
Owen.
p.s I've done a control module map for this Climatic unit so that a label file can be made up for it since it looks very similiar to the golf one.. I will upload this.
just wondering if anyone has seen an issue like this before..
we have a 2008 Audi A3 (8P) which came in initially for non working Aircon issue.
The system needed recharging so it was purged, leak tested (and appeared to be leak free) and recharged.
This car has the manual temp control "Climatic" system. When tested first, the compressor appeared to come on (LED lit on A/C button and compressor could be heard loading the engine) but within 20 or 30 seconds, the refrigerant pressure on both the measuring blocks live data and the A/C service unit high side pressure gauge went up to over 25 bar, well outside of the normal operating range. The A/C was turned off before the pressure went any higher.
We noticed that the cooling fans failed to spin up as the pressure built, which would explain why the pressure went so high. Its possible this was responsible for the initial loss of refrigerant, as the excessive pressure possibly opened a relief valve.
On one subsequent test, the system appeared to work normally, and this time we were watching the live data on the climatic unit via VCDS. The cooling fans were coming on, and the compressor regulation current was varying from its maximum of around 750 mA at the start, back to around 500 mA as the pressure built up, and kept changing, meanwhile the high pressure stabilised below 20 bar, the cooling fans were running and the vents were blowing cold air and the A/C seemed to be functioning as expected.
but after stopping and going for tea, we tested again and again this time, the pressure kept increasing, the fans never came on and again we had to shut off the A/C before something gave. We noticed that the compressor regulating current stayed at 750 mA, and what looked like the "cooling fan" speed value stayed at 10%. It seemed as if the system is not responding to the G65 high pressure signal. Every subsequent test had the same result.
On the engine ECU, the cooling fans respond perfectly to the output test every time. So we know the fans are working.
One issue we had was VCDS has no label file for this particular climatic control unit (8P0-820-047-D). the above measuring blocks I've mentioned were fairly obvious from their "probable" labels in VCDS. however we checked with another scan tool and found a parameter for "requested fan speed" also. looking at this value and repeating the test, we found that the requested fan speed value was actually rising up to a maximum of 90% as the pressure begins to climb. however the parameter "actual fan speed" stayed at 10%.
There are no fault codes in either the climatic unit or the engine controller, and we know the G65 refrigerant pressure sender is good as the measuring block reading matches the actual gauge reading on the service station. looking at a label file for a golf V climatic controller, the measuring blocks look very similar, so with the parameters from the other scan tool and the other label file, we can be reasonably confident we have the correct values.
So it seems as if the climatic controller is requesting the fan speed be increased, yet the Engine ECU is not doing as requested. furthermore, the compressor is being kept at full output. The compressor shut-off condition value goes to 0 when the A/C is turned on, and never changes either.
the full auto scan shows no other real issues, there is a control module fault in the instruments but this seems to have been there for some time before this fault. no communication errors. And the G65 and other A/C info is showing up in the engine controller, so we know the climatic and Engine controller are "talking". The radio fault codes are due to the radio having been removed at the time to allow access to the climatic unit.
we also disconnected and reconnected the battery in case of any silly software "lockups" but no difference.
Then in the absence of any other obvious problems, we obtained another climatic unit which has a later software version but this failed to resolve the issue.
full auto scan below.
Any Ideas to solve this mystery greatly appreciated..
thanks for reading..
Owen.
p.s I've done a control module map for this Climatic unit so that a label file can be made up for it since it looks very similiar to the golf one.. I will upload this.
Code:
Thursday,15,July,2021,20:49:35:11065
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x64
VCDS Version: 21.3.0.0 (x64) HEX-V2 CB: 0.4543.4
Data version: 20210226 DS325.0
www.Ross-Tech.com
VIN: WAUZZZ8P29A029202 License Plate: Redacted
Mileage: 254220km-157964mi Repair Order:
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Chassis Type: 8P-AU35 (1K0)
Scan: 01 03 08 09 15 16 17 19 25 42 44 46 52 56
VIN: WAUZZZ8P29A029202 Mileage: 254220km-157964miles
01-Engine -- Status: OK 0000
03-ABS Brakes -- Status: OK 0000
04-Steering Angle -- Status: OK 0000
08-Auto HVAC -- Status: OK 0000
09-Cent. Elect. -- Status: OK 0000
15-Airbags -- Status: OK 0000
16-Steering wheel -- Status: OK 0000
17-Instruments -- Status: Malfunction 0010
19-CAN Gateway -- Status: Malfunction 0010
25-Immobilizer -- Status: OK 0000
42-Door Elect, Driver -- Status: OK 0000
44-Steering Assist -- Status: Malfunction 0010
46-Central Conv. -- Status: OK 0000
52-Door Elect, Pass. -- Status: OK 0000
56-Radio -- Status: Cannot be reached 1100
-------------------------------------------------------------------------------
Address 01: Engine Labels: 03G-906-021-BLS.clb
Part No SW: 03G 906 056 S HW: 03G 906 021 AB
Component: R4 1,9L EDC G000SG 2917
Revision: --H08--- Serial number: AUX7Z0H7FND0DQ
Coding: 0000071
Shop #: WSC 66565 257 00032
VCID: 372B2A0A934F37237E9-8062
No fault code found.
Readiness: 0 0 0 0 0
-------------------------------------------------------------------------------
Address 03: ABS Brakes (-----) Labels:. 1K0-907-379-60EC1F.clb
Part No SW: 1K0 907 379 AD HW: 1K0 907 379 AD
Component: ESP MK60EC1 H35 0109
Revision: 00H35001
Coding: 1342201209240003C80D04E4901B00813800
Shop #: WSC 51367 001 104857
VCID: 74B1DD06CEB99C3B9BB-8020
No fault code found.
-------------------------------------------------------------------------------
Address 08: Auto HVAC Labels: None
Part No SW: 8P0 820 047 D HW: 8P0 820 047 D
Component: J255 Klima Man H08 0060
Revision: 00H08004 Serial number: 00000000000000
Shop #: WSC 00000 000 00000
VCID: 313F14127D2BE91330D-8064
No fault code found.
-------------------------------------------------------------------------------
Address 09: Cent. Elect. Labels:. 8P0-907-279-30-H.lbl
Part No SW: 8P0 907 279 N HW: 8P0 907 279 N
Component: Bordnetz-SG H54 2801
Revision: 00H54000 Serial number: 00000008796869
Coding: 10A82F07A0141380EF00001C4F00000000084A1564010003002000000000
Shop #: WSC 06314 000 08192
VCID: 48C959F6EEB148DB073-801C
Subsystem 1 - Part No: 8P2 955 119 F Labels: 1KX-955-119.CLB
Component: Wischer AU350 H10 0040
Coding: 00056595
Shop #: WSC 06314
No fault code found.
-------------------------------------------------------------------------------
Address 15: Airbags (J234) Labels:* 8P0-959-655-10.clb
Part No SW: 8P0 959 655 J HW: 8P0 959 655 J
Component: Airbag AU1042 H06 0090
Revision: -------- Serial number: 003000000000
Coding: 303142413039303030384A55305238503053
Shop #: WSC 06314 000 00000
ASAM Dataset: EV_Airba10AURB4 001001
ROD: EV_Airba10AURB4_AU35.rod
VCID: 49CF5CF2F93BB1D318D-801C
Crash sensor for side airbag: driver side:
Serial number: 34928RB400003FAF86A6
Front Passenger's Side Airbag Crash Sensor:
Serial number: 35028RB400003FB29BB-
Rear Side Airbag Crash Sensor (on driver's side):
Serial number: 35128RB400003FAE3F0Z
Passenger side rear thorax airbag crash sensor:
Serial number: 35228RB400003FB29A0Q
Crash sensor for front airbag: driver side:
Serial number: 35547RB400003FE1176R
Crash sensor for front airbag: front passenger side:
Serial number: 35647RB400003FE1E2D0
No fault code found.
-------------------------------------------------------------------------------
Address 16: Steering wheel Labels: 8P0-953-549-F.lbl
Part No SW: 8P0 953 549 F HW: 8P0 953 549 F
Component: J0527 H36 0070
Coding: 0000042
Shop #: WSC 06314 000 00000
VCID: 41DF44D2CD8B7993C0D-8014
No fault code found.
-------------------------------------------------------------------------------
Address 17: Instruments Labels: 8P0-920-xxx-17-MY8.clb
Part No SW: 8P0 920 982 C HW: 8P0 920 982 C
Component: KOMBIINSTR. VDO H18 0830
Revision: D0H18006 Serial number: 2247H006004703
Coding: 0004428
Shop #: WSC 00586 210 88211
VCID: 392F2C32A55B215388D-806C
1 Fault Found:
00003 - Control Module
014 - Defective
Freeze Frame:
Fault Status: 01101110
Fault Priority: 1
Fault Frequency: 1
Reset counter: 255
Mileage: 215874 km
Time Indication: 0
Date: 2018.11.18
Time: 10:20:49
-------------------------------------------------------------------------------
Address 19: CAN Gateway Labels:. 1K0-907-530-V3.clb
Part No SW: 1K0 907 530 Q HW: 1K0 907 951
Component: J533__Gateway H16 0202
Revision: H16 Serial number: 2700K0880108B5
Coding: E9801F060002020101
Shop #: WSC 06314 000 00000
VCID: 353720028943C5336C5-8060
2 Faults Found:
01305 - Databus for Infotainment
004 - No Signal/Communication
Freeze Frame:
Fault Status: 01100100
Fault Priority: 1
Fault Frequency: 254
Reset counter: 190
Mileage: 253724 km
Time Indication: 0
Date: 2021.06.21
Time: 02:33:53
01304 - Radio
004 - No Signal/Communication
Freeze Frame:
Fault Status: 01100100
Fault Priority: 2
Fault Frequency: 2
Reset counter: 176
Mileage: 253724 km
Time Indication: 0
Date: 2021.06.21
Time: 02:33:58
-------------------------------------------------------------------------------
Address 25: Immobilizer Labels: 1K0-920-xxx-25.clb
Part No SW: 8P0 920 982 C HW: 8P0 920 982 C
Component: KOMBIINSTR. VDO H18 0830
Revision: D0H18006 Serial number: AUX7Z0H7FND0DQ
Shop #: WSC 00000 000 00000
VCID: 392F2C32A55B215388D-806C
No fault code found.
-------------------------------------------------------------------------------
Address 42: Door Elect, Driver Labels: 8P0-959-801-MAX3.lbl
Part No SW: 8P0 959 801 M HW: 8P0 959 801 M
Component: Tuer-SG H04 0100
Coding: 0000564
Shop #: WSC 00586 210 81414
VCID: 45D750C2D9A355B3FC5-8010
No fault code found.
-------------------------------------------------------------------------------
Address 44: Steering Assist Labels: 1K0-909-14x-GEN3.clb
Part No: 1K0 909 144 C
Component: EPS_ZFLS Kl. 232 2301
Revision: 00H15000
Shop #: WSC 02069 000 90108
VCID: 2A0D037E50FD9ACBF17-807E
1 Fault Found:
00778 - Steering Angle Sensor (G85)
000 - - - MIL ON
Freeze Frame:
Fault Status: 11100000
Fault Priority: 2
Fault Frequency: 1
Reset counter: 255
Time Indication: 0
Date: 2000.00.00
Time: 31:63:63
Freeze Frame:
Battery Volts: 12.1 V
PD
Temperature: 30.0°C
Count: 2
Steering Angle: 0.00°
Count: 0
SteerAng n.Init
-------------------------------------------------------------------------------
Address 46: Central Conv. Labels: 8P0-959-433.lbl
Part No: 8P0 959 433 J
Component: KSG H11 0080
Coding: 1980200002186D2D8505489AC637
Shop #: WSC 06314 000 00000
VCID: 43D34EDAD7976B83D21-8016
Subsystem 1 - Part No: 1K0 951 605 C
Component: LIN BACKUP HORN H03 1301
Subsystem 2 - Part No: 1K0 907 719 C
Component: Neigungssensor 005 0003
Subsystem 3 - Part No: 8P0 951 177
Component: Innenraumueberw.H04 0020
No fault code found.
-------------------------------------------------------------------------------
Address 52: Door Elect, Pass. Labels:. 1K0-959-702-MIN3.clb
Part No SW: 8P0 959 802 K HW: 8P0 959 802 K
Component: Tuer-SG H03 0060
Coding: 0000564
Shop #: WSC 06314 000 00000
VCID: 44D14DC6D2996CBBEBB-8010
No fault code found.
-------------------------------------------------------------------------------
Address 56: Radio
Cannot be reached
End----------(Elapsed Time: 00:57, VBatt start/end: 12.3V/12.3V)-----------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Address 17: DTCs cleared
I did fully read your initial post. I had indeed assumed you had used an A/C service station; I was thinking previous ‘persons unknown’ may have attempted a tin-can re-gas.