Code P1602-002 - Power Supply to terminal 30 voltage too low

[flat12]

Code P1602-002 = Power to Terminal 30 voltage too low. The wiring diagram below shows Relay J271 and J623 ECM - on my Audi Q7. Per the manual with the ignition on...there should be battery voltage at Relay J-271 socket 30, however I'm getting nothing. I have removed the wiper arms from the transmission, and pulled off the windshield cowl cover, so I can now physically access the ECM. I think I need to remove the connector to the ECM and check the wire continuity, but I am unsure how to remove the tamper-proof retaining screws. Guidance is requested.

 

[Jack@European_Parts]

Auto-scan in code tags to commence please......

 

[flat12]

Hello Jack....the last full auto-scan was a month ago (below)...the Q7 has just been sitting since that time. I kept getting he EPC light, so I disconnected components to see if I could find out what was triggering it, my efforts were not conclusive. So the Q7 has both MAF's and both HPFP's disconnected. I also have the air intake tube going to the throttle body removed so I could access the wire harnesses at the back of the engine. For fun...wise or not....I decided to see if it would start this morning, and it did immediately...and ran quite smoothly for a few seconds, and then resumed it's rough idle, it rev'd up fine. I checked the engine management system to see what codes were there, and it showed MAF's as signal too low, Bank #2 fuel pressure regulator no signal, and the P1602-002 power to terminal 30 voltage too low....so I figured I'd tackle this low voltage issue first.

Chassis Type: 4L0
Scan: 01 02 03 05 07 08 09 0E 0F 15 16 17 19 28 34 36 37 3C 42 46
          47 4F 52 55 56 61 62 67 69 6C 6D 6F 72 76 77

VIN: WA1AV94L47D009991   Mileage: 165670km/102942miles

00-Steering Angle Sensor -- Status: OK 0000
01-Engine -- Status: Malfunction 0010
02-Auto Trans -- Status: Malfunction 0010
03-ABS Brakes -- Status: Malfunction 0010
05-Acc/Start Auth. -- Status: Malfunction 0010
07-Control Head -- Status: Malfunction 0010
08-Auto HVAC -- Status: OK 0000
09-Cent. Elect. -- Status: OK 0000
0E-Media Player 1 -- Status: OK 0000
0F-Digital Radio -- Status: OK 0000
15-Airbags -- Status: OK 0000
16-Steering wheel -- Status: OK 0000
17-Instruments -- Status: OK 0000
19-CAN Gateway -- Status: Malfunction 0010
28-HVAC, Rear -- Status: Malfunction 0010
34-Level Control -- Status: Malfunction 0010
36-Seat Mem. Drvr -- Status: OK 0000
37-Navigation -- Status: Malfunction 0010
3C-Lane Change -- Status: OK 0000
42-Door Elect, Driver -- Status: Malfunction 0010
46-Central Conv. -- Status: OK 0000
47-Sound System -- Status: Malfunction 0010
4F-Centr. Electr. II -- Status: OK 0000
52-Door Elect, Pass. -- Status: OK 0000
55-Xenon Range -- Status: OK 0000
56-Radio -- Status: OK 0000
61-Battery Regul. -- Status: Malfunction 0010
62-Door,Rear Left -- Status: Malfunction 0010
67-Voice Control -- Status: OK 0000
69-Trailer -- Status: Malfunction 0010
6C-Back-up Cam. -- Status: Malfunction 0010
6D-Trunk Elect. -- Status: OK 0000
6F-Centr. Conv. II -- Status: OK 0000
72-Door, Rear Right -- Status: OK 0000
76-Park Assist -- Status: OK 0000
77-Telephone -- Status: OK 0000
 
-------------------------------------------------------------------------------
Address 01: Engine        Labels: Redir Fail!
   Part No SW: 4L0 910 560 C    HW: 4L0 907 560 A
   Component: 4.2l V8/4V          0060  
   Revision: --H16---    Serial number:               
   Coding: 01210009190F0D60
   Shop #: WSC 08166 444 102996

16 Faults Found:
008583 - Bank 1; System too Lean at Idle 
               P2187 - 004 - No Signal/Communication - MIL ON
             Freeze Frame:
                    Fault Status: 11100100
                    Fault Priority: 0
                    Fault Frequency: 1
                    Mileage: 157481 km
                    Time Indication: 0
                    Date: 2015.12.24
                    Time: 09:22:06

             Freeze Frame:
                    RPM: 774 /min
                    Load: 15.7 %
                    Speed: 0.0 km/h
                    Temperature: 99.0°C
                    Temperature: 42.0°C
                    Absolute Pres.: 1010.0 mbar
                    Voltage: 14.097 V

008585 - Bank 2; System too Lean at Idle 
               P2189 - 004 - No Signal/Communication - MIL ON
             Freeze Frame:
                    Fault Status: 11100100
                    Fault Priority: 0
                    Fault Frequency: 1
                    Mileage: 157481 km
                    Time Indication: 0
                    Date: 2015.12.24
                    Time: 09:22:10

             Freeze Frame:
                    RPM: 778 /min
                    Load: 15.7 %
                    Speed: 0.0 km/h
                    Temperature: 99.0°C
                    Temperature: 42.0°C
                    Absolute Pres.: 1010.0 mbar
                    Voltage: 13.970 V

000135 - Fuel Rail/System Pressure: Too Low 
               P0087 - 008 - Implausible Signal - Intermittent
             Freeze Frame:
                    Fault Status: 00101000
                    Fault Priority: 0
                    Fault Frequency: 29
                    Mileage: 165100 km
                    Time Indication: 0
                    Date: 2016.03.18
                    Time: 16:50:07

             Freeze Frame:
                    RPM: 2084 /min
                    Load: 69.0 %
                    Speed: 55.0 km/h
                    Temperature: 91.0°C
                    Temperature: 28.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 14.351 V

000135 - Fuel Rail/System Pressure: Too Low 
               P0087 - 002 - Lower Limit Exceeded - MIL ON
             Freeze Frame:
                    Fault Status: 11100010
                    Fault Priority: 0
                    Fault Frequency: 5
                    Mileage: 165109 km
                    Time Indication: 0
                    Date: 2016.03.19
                    Time: 08:41:52

             Freeze Frame:
                    RPM: 3155 /min
                    Load: 11.8 %
                    Speed: 88.0 km/h
                    Temperature: 92.0°C
                    Temperature: 15.0°C
                    Absolute Pres.: 1000.0 mbar
                    Voltage: 14.097 V

001112 - Evap System Purge Control Valve (N80): Short to Ground 
               P0458 - 002 - Lower Limit Exceeded - MIL ON
             Freeze Frame:
                    Fault Status: 11100010
                    Fault Priority: 0
                    Fault Frequency: 1
                    Mileage: 165644 km
                    Time Indication: 0

             Freeze Frame:
                    RPM: 1406 /min
                    Load: 36.5 %
                    Speed: 0.0 km/h
                    Temperature: 51.0°C
                    Temperature: 33.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 12.446 V

005173 - Secondary Air Pump Relay (J299): Short to Ground 
               P1435 - 002 - Lower Limit Exceeded - MIL ON
             Freeze Frame:
                    Fault Status: 11100010
                    Fault Priority: 0
                    Fault Frequency: 1
                    Mileage: 165644 km
                    Time Indication: 0

             Freeze Frame:
                    RPM: 1406 /min
                    Load: 36.5 %
                    Speed: 0.0 km/h
                    Temperature: 51.0°C
                    Temperature: 33.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 13.462 V

004763 - Fuel Pressure Regulator Valve; Bank 2 (N276): Open Circuit 
               P129B - 004 - No Signal/Communication - Intermittent - MIL ON
             Freeze Frame:
                    Fault Status: 10100100
                    Fault Priority: 0
                    Fault Frequency: 4
                    Mileage: 165644 km
                    Time Indication: 0

             Freeze Frame:
                    RPM: 466 /min
                    Load: 97.6 %
                    Speed: 0.0 km/h
                    Temperature: 32.0°C
                    Temperature: 33.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 11.303 V

000258 - Mass Air Flow Sensor (G70): Signal too Low 
               P0102 - 002 - Lower Limit Exceeded - MIL ON
             Freeze Frame:
                    Fault Status: 11100010
                    Fault Priority: 0
                    Fault Frequency: 1
                    Mileage: 165644 km
                    Time Indication: 0

             Freeze Frame:
                    RPM: 1071 /min
                    Load: 20.8 %
                    Speed: 0.0 km/h
                    Temperature: 51.0°C
                    Temperature: 33.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 12.192 V

000268 - Mass Air Flow Sensor (G246): Signal too Low 
               P010C - 002 - Lower Limit Exceeded - MIL ON
             Freeze Frame:
                    Fault Status: 11100010
                    Fault Priority: 0
                    Fault Frequency: 1
                    Mileage: 165644 km
                    Time Indication: 0

             Freeze Frame:
                    RPM: 1071 /min
                    Load: 20.8 %
                    Speed: 0.0 km/h
                    Temperature: 51.0°C
                    Temperature: 33.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 12.192 V

009217 - EVAP Leak Detection Pump Control Circuit: Short to GND 
               P2401 - 002 - Lower Limit Exceeded - MIL ON
             Freeze Frame:
                    Fault Status: 11100010
                    Fault Priority: 0
                    Fault Frequency: 1
                    Mileage: 165644 km
                    Time Indication: 0
                    Date: 2016.03.27
                    Time: 09:25:58

             Freeze Frame:
                    RPM: 1126 /min
                    Load: 38.4 %
                    Speed: 4.0 km/h
                    Temperature: 51.0°C
                    Temperature: 33.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 14.351 V

000768 - Random/Multiple Cylinder Misfire Detected 
               P0300 - 001 - Upper Limit Exceeded - MIL ON
             Freeze Frame:
                    Fault Status: 11100001
                    Fault Priority: 0
                    Fault Frequency: 1
                    Mileage: 165645 km
                    Time Indication: 0
                    Date: 2016.03.27
                    Time: 09:26:51

             Freeze Frame:
                    RPM: 3015 /min
                    Load: 51.0 %
                    Speed: 38.0 km/h
                    Temperature: 54.0°C
                    Temperature: 30.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 14.224 V

000771 - Cylinder 3: Misfire Detected 
               P0303 - 001 - Upper Limit Exceeded - MIL ON
             Freeze Frame:
                    Fault Status: 11100001
                    Fault Priority: 0
                    Fault Frequency: 1
                    Mileage: 165645 km
                    Time Indication: 0
                    Date: 2016.03.27
                    Time: 09:26:51

             Freeze Frame:
                    RPM: 3015 /min
                    Load: 51.0 %
                    Speed: 38.0 km/h
                    Temperature: 54.0°C
                    Temperature: 30.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 14.224 V

000770 - Cylinder 2: Misfire Detected 
               P0302 - 001 - Upper Limit Exceeded - MIL ON
             Freeze Frame:
                    Fault Status: 11100001
                    Fault Priority: 0
                    Fault Frequency: 1
                    Mileage: 165645 km
                    Time Indication: 0
                    Date: 2016.03.27
                    Time: 09:26:51

             Freeze Frame:
                    RPM: 3015 /min
                    Load: 51.0 %
                    Speed: 38.0 km/h
                    Temperature: 54.0°C
                    Temperature: 30.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 14.224 V

008852 - Fuel Pressure Regulator Valve (N276): Open Circuit 
               P2294 - 004 - No Signal/Communication - Intermittent - MIL ON
             Freeze Frame:
                    Fault Status: 10100100
                    Fault Priority: 0
                    Fault Frequency: 5
                    Mileage: 165647 km
                    Time Indication: 0
                    Date: 2016.03.27
                    Time: 10:50:44

             Freeze Frame:
                    RPM: 1720 /min
                    Load: 14.9 %
                    Speed: 63.0 km/h
                    Temperature: 64.0°C
                    Temperature: 35.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 14.351 V

000769 - Cylinder 1: Misfire Detected 
               P0301 - 001 - Upper Limit Exceeded - MIL ON
             Freeze Frame:
                    Fault Status: 11100001
                    Fault Priority: 0
                    Fault Frequency: 1
                    Mileage: 165652 km
                    Time Indication: 0
                    Date: 2016.03.28
                    Time: 05:34:50

             Freeze Frame:
                    RPM: 770 /min
                    Load: 34.5 %
                    Speed: 5.0 km/h
                    Temperature: 25.0°C
                    Temperature: 24.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 14.097 V

000773 - Cylinder 5: Misfire Detected 
               P0305 - 008 - Implausible Signal - MIL ON
             Freeze Frame:
                    Fault Status: 11101000
                    Fault Priority: 0
                    Fault Frequency: 1
                    Mileage: 165652 km
                    Time Indication: 0
                    Date: 2016.03.28
                    Time: 05:35:33

             Freeze Frame:
                    RPM: 1905 /min
                    Load: 37.2 %
                    Speed: 35.0 km/h
                    Temperature: 32.0°C
                    Temperature: 25.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 14.351 V

Readiness: 0000 1001

-------------------------------------------------------------------------------
Address 02: Auto Trans        Labels: 09D-927-750.lbl
   Part No SW: 09D 927 750 BR    HW: 09D 927 750 BR
   Component: AL 750 6A           0915  
   Revision: 00H49000    Serial number:               
   Coding: 0000504
   Shop #: WSC 31414 790 00001

1 Fault Found:
01314 - Engine Control Module 
            013 - Check DTC Memory
             Freeze Frame:
                    Fault Status: 00101000
                    Fault Priority: 2
                    Fault Frequency: 6
                    Reset counter: 0
                    Mileage: 0 km
                    Time Indication: 0
                    Date: 2005.09.20
                    Time: 12:00:00


-------------------------------------------------------------------------------
Address 03: ABS Brakes        Labels: 4L0-910-517.lbl
   Part No SW: 4L0 910 517 E    HW: 4L0 614 517 E
   Component: ESP ALLRAD MK25E1   0140  
   Revision: 00H45001    
   Coding: 0021553
   Shop #: WSC 31414 790 00001

1 Fault Found:
01314 - Engine Control Module 
            013 - Check DTC Memory
             Freeze Frame:
                    Fault Status: 01101101
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 167
                    Mileage: 165644 km
                    Time Indication: 0
                    Date: 2016.03.27
                    Time: 09:25:48

             Freeze Frame:
                    Count: 64
                    Count: 13569
                    Count: 8196
                    Count: 43264


-------------------------------------------------------------------------------

Address 07: Control Head        Labels: 4L0-910-7xx-07-H.lbl
   Part No SW: 4L0 910 729 R    HW: 4E0 035 729 A
   Component: Interfacebox    H43 1600  
   Revision: 00000000    Serial number: 354CL067501339
   Coding: 0000003
   Shop #: WSC 31414 790 00001

   Part No: 4L0 910 609 
   Component: E0380 BedienteilH01 0050

3 Faults Found:
01325 - Control Module for Tire Pressure Monitoring (J502) 
            004 - No Signal/Communication
             Freeze Frame:
                    Fault Status: 01100100
                    Fault Priority: 5
                    Fault Frequency: 1
                    Reset counter: 227
                    Mileage: 157473 km
                    Time Indication: 0
                    Date: 2015.12.24
                    Time: 05:25:29

02849 - Control Module for Lane Change Assistance (J769) 
            004 - No Signal/Communication - Intermittent
             Freeze Frame:
                    Fault Status: 00100100
                    Fault Priority: 5
                    Fault Frequency: 1
                    Reset counter: 211
                    Mileage: 165673 km
                    Time Indication: 0
                    Date: 2016.03.28
                    Time: 17:53:33

02873 - Control Module for Back-Up Camera (J772) 
            004 - No Signal/Communication - Intermittent
             Freeze Frame:
                    Fault Status: 00100100
                    Fault Priority: 5
                    Fault Frequency: 1
                    Reset counter: 202
                    Mileage: 165339 km
                    Time Indication: 0
                    Date: 2016.03.23
                    Time: 18:01:58


-------------------------------------------------------------------------------


-------------------------------------------------------------------------------
Address 19: CAN Gateway        Labels: 4L0-910-468.lbl
   Part No SW: 4L0 910 468     HW: 4L0 907 468 A
   Component: J533__Gateway   H06 0040  
   Revision: 00H06000    Serial number: 0800D0631280D7
   Coding: F7F3FE7F347A02
   Shop #: WSC 08166 444 102996

1 Fault Found:
01325 - Control Module for Tire Pressure Monitoring (J502) 
            004 - No Signal/Communication
             Freeze Frame:
                    Fault Status: 01100100
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 227
                    Mileage: 157473 km
                    Time Indication: 0
                    Date: 2015.12.24
                    Time: 05:03:56


-------------------------------------------------------------------------------
Address 28: HVAC, Rear        Labels: None
   Part No SW: 4L0 910 158     HW: 4L0 919 158 D
   Component: KLIMABETAETIGUNGH05 0040  
   Revision: 00---006    Serial number: 00000000014930
   Coding: 0000006
   Shop #: WSC 31414 790 00001

1 Fault Found:
00003 - Control Module 
            003 - Mechanical Failure - Intermittent
             Freeze Frame:
                    Fault Status: 00100011
                    Fault Priority: 2
                    Fault Frequency: 11
                    Mileage: 124044 km
                    Time Indication: 0
                    Date: 2013.12.13
                    Time: 21:56:17


-------------------------------------------------------------------------------
Address 34: Level Control        Labels: None
   Part No SW: 4L0 910 553 A    HW: 4L0 907 553 
   Component: LUFTFDR.-CDC    H03 7470  
   Revision: --H03001    Serial number: 15.1528-0082.2
   Coding: 0015520
   Shop #: WSC 08166 444 102996

1 Fault Found:
01577 - Turn-Off due to Over-Temp 
            001 - Upper Limit Exceeded - Intermittent
             Freeze Frame:
                    Fault Status: 00100001
                    Fault Priority: 6
                    Fault Frequency: 4
                    Reset counter: 207
                    Mileage: 163368 km
                    Time Indication: 0
                    Date: 2016.03.05
                    Time: 14:05:24

             Freeze Frame:
                    Error Code: 68


-------------------------------------------------------------------------------

Address 37: Navigation        Labels: 4E0-910-88x-37.lbl
   Part No SW: 4E0 910 888 M    HW: 4E0 919 887 C
   Component: MNS US          H45 1100  
   Revision: 00000000    Serial number: 306C9067500421
   Shop #: WSC 31414 790 00001

1 Fault Found:
02927 - DVD Read Error 
            000 -  -  - Intermittent
             Freeze Frame:
                    Fault Status: 00100000
                    Fault Priority: 6
                    Fault Frequency: 9
                    Reset counter: 185
                    Mileage: 162578 km
                    Time Indication: 0
                    Date: 2016.03.04
                    Time: 17:33:00

             Freeze Frame:
                    Hex Value: 0x56ED
                    Hex Value: 0x0FC5
                    Hex Value: 0x0401
                    Hex Value: 0x0000


-------------------------------------------------------------------------------

Address 42: Door Elect, Driver        Labels: 4L0-910-793-42.lbl
   Part No SW: 4L0 910 793 B    HW: 4L0 959 793 B
   Component: TSG FA          H12 0130  
   Revision: 00-00000    
   Coding: 0051915
   Shop #: WSC 31414 790 00001

1 Fault Found:
02126 - Central Locking Button; Exterior Door Handle 
            008 - Implausible Signal
             Freeze Frame:
                    Fault Status: 01101000
                    Fault Priority: 3
                    Fault Frequency: 254
                    Reset counter: 165
                    Mileage: 155790 km
                    Time Indication: 0
                    Date: 2015.10.08
                    Time: 22:20:20


-------------------------------------------------------------------------------

Address 47: Sound System        Labels: 4L0-910-223-BO.lbl
   Part No SW: 4L0 910 223 A    HW: 4L0 035 223 A
   Component: DSP-High AU716  H02 0090  
   Revision: PROD_01     Serial number: 00000000205110
   Coding: 0000026
   Shop #: WSC 31414 790 00001

1 Fault Found:
00870 - Bass Speaker Front Left (R21) 
            011 - Open Circuit - Intermittent
             Freeze Frame:
                    Fault Status: 00111011
                    Fault Priority: 5
                    Fault Frequency: 3
                    Reset counter: 209
                    Mileage: 165638 km
                    Time Indication: 0
                    Date: 2016.03.26
                    Time: 18:52:32


-------------------------------------------------------------------------------

Address 61: Battery Regul.        Labels: 4F0-910-181.lbl
   Part No SW: 4L0 910 181     HW: 4L0 915 181 
   Component: J0644 BEM       H12 0530  
   Revision: --------    Serial number: 00000000007731
   Shop #: WSC 08166 444 00177

   Part No: 4F0 915 105 D
   Component: von VA0  2603131260       
   Coding: 344630393135313035442056413032363033313331323630
   Shop #: WSC 31414 790 00001

1 Fault Found:
03041 - Energy Management Active 
            000 -  -  - Intermittent
             Freeze Frame:
                    Fault Status: 00100000
                    Fault Priority: 7
                    Fault Frequency: 85
                    Mileage: 124562 km
                    Time Indication: 0
                    Date: 2013.12.26
                    Time: 16:04:40


-------------------------------------------------------------------------------
Address 62: Door,Rear Left        Labels: 4L0-910-795.lbl
   Part No SW: 4L0 910 795 B    HW: 4L0 959 795 B
   Component: TSG HL          H21 0050  
   Coding: 0051722
   Shop #: WSC 31414 790 00001

1 Fault Found:
02126 - Central Locking Button; Exterior Door Handle 
            008 - Implausible Signal
             Freeze Frame:
                    Fault Status: 01101000
                    Fault Priority: 3
                    Fault Frequency: 5
                    Reset counter: 228
                    Mileage: 128378 km
                    Time Indication: 0
                    Date: 2014.04.04
                    Time: 15:03:53


-------------------------------------------------------------------------------

Address 69: Trailer (J345)       Labels: None
   Part No SW: 4E0 907 383 H    HW: 4E0 907 383 G
   Component: Anhaenger     H08 0080  
   Revision: 2A002002    Serial number: 00000116067289
   Coding: 0200000000000000
   Shop #: WSC 08166 444 09063

2 Faults Found:
02579 - Trailer; Left Brake Lamps (M65) 
            010 - Open or Short to Plus - MIL ON
             Freeze Frame:
                    Fault Status: 11101010
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 121
                    Mileage: 164761 km
                    Time Indication: 0
                    Date: 2016.03.08
                    Time: 11:54:48

02580 - Trailer; Right Brake Lamps (M66) 
            010 - Open or Short to Plus - MIL ON
             Freeze Frame:
                    Fault Status: 11101010
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 121
                    Mileage: 164761 km
                    Time Indication: 0
                    Date: 2016.03.08
                    Time: 11:54:48


-------------------------------------------------------------------------------
Address 6C: Back-up Cam.        Labels: 4L0-910-441.lbl
   Part No SW: 4L0 910 441     HW: 4L0 907 441 
   Component: J772__Rearview      0020  
   Revision: --H10---    Serial number: 525PA8-J631307
   Coding: 1010001
   Shop #: WSC 08166 444 102996

1 Fault Found:
03006 - Back-up Camera System not calibrated 
            000 -  - 
             Freeze Frame:
                    Fault Status: 01100000
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 138
                    Time Indication: 0

             Freeze Frame:
                        Invalid
                        Invalid
                        Invalid

 

[Jack@European_Parts]

Please sir, before anything else, take the engine ecu out and apart to inspect for water ingress.
If corrosion is present and you need an ecu with data transfer we can help.

You absolutely must check this first, to rule out the fact there could be nothing possibly wrong under the hood.


This is a common issue......

 

[flat12]

The ECU physically looks good from the outside, the bottom panel is nice and shiny. Never the less I will remove it. How do I remove the ECU Connector retainer "bolts"...? The manual says to use a heat gun to loosen up the thread locker used at the factory and then use vice grips to twist out the bolts. I'm tempted to carefully grind the heads off.....

 

[flat12]

Here are picture of the ECU, it has the usual oxidation and stuff on the top side, but the underside looks pretty good.

 

[Jack@European_Parts]

What about after the rear cover is removed and be careful doing it?
It can always be resealed.
If dry and clean I recommend bagging the controller when putting it back with air snorkel tube.

 

[flat12]

I will try and use a dremel and slot the head of the tamper-proof screws. Then I will remove the brackets around the large multi-pin connectors, and test the gray/black wire going to J271 Relay terminal 30 for continuity. If all checks out okay....I'll will post the results and go from there with your guidance. Thank You Jack.

 

[Jack@European_Parts]

I will try and use a dremel and slot the head of the tamper-proof screws. Then I will remove the brackets around the large multi-pin connectors, and test the gray/black wire going to J271 Relay terminal 30 for continuity. If all checks out okay....I'll will post the results and go from there with your guidance. Thank You Jack.

Your welcome .......and FYI that rotted torx screw is a sign water is present.

Often the power supply driver gets wiped in these MED9 units which switch's the consumer and power supply relays.

It additionally bothers me that 0x09 is not present after quick review.....

Please post more data from the JPPSG format.
http://forums.ross-tech.com/showthr...essional-Problem-Solver-Guide-quot-JPPSG-quot

The white PR code tag from the spare tire trunk area, and or service books first page.

According to what I see in the microfilm it should have these central electrics.

4F0910279J
Control unit 2 4F0907280B


or

4F0910289F
Control unit 2 4L0910290A
Vehicle data

Vehicle Identification No.	WA1AV94L47D009991
Model	audi q7 qu. 4.2 AQ7
Date of production	03.04.2006
Year	2007
Sales type	4LB5EL
Engine Code	BAR
Transmission Code	HPH
Axle drive	6A
Equipment	CB
Roof color	Q4
Exterior color / Paint Code	Q4 / Y7G

Based on this I would want to know the status of the Ignition switch and all terminal relays.

 

[flat12]

More to do but here is where I'm at right now. I managed to remove the brackets holding the harness to the ECM. I then checked the continuity of the 0.5mm gray/black wire going from J271 Relay socket terminal 30 to the ECM Connector T94 at position #69...I read 1 ohm resistance which to me is perfect. So at least I know the wire is good. I'm posting a couple more pictures as an FYI.

Jack...I will not carefully try and remove the back cover of the ECM and report back. I will also post the JPPSG requirements....

 

[Jack@European_Parts]

OHM test what what what................

Did you know if only one strand of wire is present for any circuit, it will read as being accurate on the DVOM for resistance?

Resistance is futile applies!................

Always!........ load light test a track from end to end.
Before hooking up know all tracks as per the WD.

You can also run the meter in series under the amp draw, to verify the pull and that it can light the bulb being brilliant.

 

[flat12]

I tried to carefully pry off the back of the ECM, it is not a fun process. Although that one screw was corroded, I don't see any visual evidence of water intrusion. As you can see there is sealant not only around the perimeter but also along a 1/2 inch wide strip along one side of the PC Board. As I was prying off the backing plate, I could see the PC Board lifting up a bit...maybe 1/8 of an inch or so. So I used a screwdriver and carefully separated the PC Board from the backing plate...before completely removing it. Hopefully what movement did occur to the PC Board will not hurt anything...???

I will get more information about the Q7 and post it shortly.

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Jack...about that gray/black wire...thank you, I will do a light load test on it.

 

[flat12]

To apply a light load to the gray/black wire I used a tail light bulb as a load...and it lit up okay using a 9 volt battery, should I use the Q7's battery for this test? (worried about too much current flow)

 

[Jack@European_Parts]

I was going to say use a 55 watt headlight bulb and a real 12V car battery .........if the wire fries......... something was wrong from start.

You need to pry the board out carefully on the ecu and inspect top side .........be sure to use a magnifier mirror to inspect with good lighting.

Take your time........!

I'm proud of you so far, because I have seen some horrible rear case removals from "tuners"!

Hope it's clean......

When resealing......... take RTV and install on the cover, and drop on.......... do not over use it!

Than remember to bag and snorkel the unit for future protection, because we know water was already there from that screw making its way!

 

[Jack@European_Parts]

Here in today for same crap different shovel...........Q7

Look at both sides and here is why.........

FYI don't touch or spray board with anything unless you know what you are doing!

As you can see the missing vent cap is a conduit right to the board for this one........

 

[flat12]

Jack...about testing that wire, it's only 0.5mm diameter...so should I really subject it to the Q7's battery and a headlight bulb? Tonight I will carefully remove the circuit board and look at the backside for any issues. What does water damage typically look like? From your picture it looks like there is more sealant applied in 2 strips on each side of the circuit board. Tearing into the ECM...it stresses me out like I'm trying to perform open heart surgery....I'm past the point of no return now.

 

[Jack@European_Parts]

See that green mark dead center on top of ECU?

You only are testing fast to see if it heats up and lights up like a fuse.

Then use a lower wattage bulb if afraid or a 1-2 amp fuse in line to protect to further test the circuit.

 

[Dutchie]

Perhaps i'm asking a stupid qeusting. But if i see the picture the relay get it singal from the ECM. Is there on T94/19?? (cant see clearly) a voltage, if not remove the wire from the connector and recheck. If still not, is the ECM getting all of its power and grounds?

No offence to Jack@European_Parts, but imidiate pulling an ECM apart is not my way to go. Yet again, no offence.

 

[Jack@European_Parts]

Perhaps i'm asking a stupid qeusting. But if i see the picture the relay get it singal from the ECM. Is there on T94/19?? (cant see clearly) a voltage, if not remove the wire from the connector and recheck. If still not, is the ECM getting all of its power and grounds?

No offence to Jack@European_Parts, but imidiate pulling an ECM apart is not my way to go. Yet again, no offence.

No offense taken.........I respectfully disagree.

A TSB is always a first thing to check.

In the case for this vehicle, and the fact that this a serious problem for Q7......... it absolutely is a must.
This part is damaged in such significance of numbers, that there are none available in any USA dealer, and are on international back order.

This unit was just starting to see water so if its dry and he bags the unit he will be light years ahead of the cost or damages prevented going forward.

I had the forethought to stock up early on this application, when seeing the signs to come.

 

[flat12]

Not sure what the best way is to pry up the circuit board. Does the connector come out with it? Is there a certain edge I need to lift first? Is this just a case where I lift...and try to cut the sealant with a razor? Or do I lift and keep lifting until the board pops free? Jack....I know I sound like a little girl....but I'm scared.