VAG-COM/VCDS Logging

VAG-COM or VCDS offers a slow way to datalog diagnostic channels on the ECU which can be valuable when diagnosing issues, such as a boost leak. If our support team needs data logs via VCDs, use this guide. It's always preferable to use APR Mobile, where available.


Plug in the OBDII cable, and launch the program with the engine running. Turn off A/C and the traction control system. Roll the windows up. If you just switched octanes, follow our fuel guide. The test will need to be run at wide open throttle in 4th gear from 1,500 RPM to redline unless otherwise specified. Please provide a minimum of 4 tests on the same stretch of road.

Load VCDS and click "Select"

Click "01-Engine"

Click "Adv. meas. blocks"

Enable turbo mode. Enable UDS if available. Select the measuring blocks provided by the support team. Then click "LOG".

Sample Logging Groups

Logging groups will depend on the engine, available values, and several other factors. Always try to group the number in like groups as this will speed up logging sample rates.


The following is an example of an MED 9 ECU found in the 2.0 TFSI.


Boost / Fueling

001-1 Engine Speed

014-3 Misfire Sum

031-1 Lambda, Current Value

054-3 Accelerator Pedal Position

054-4 Throttle Plate Angle

101-3 Injection Timing (Median)

103-1 Current Fuel Pressure

114-4 N75 Duty Cycle

115-3 Boost Pressure (Specified)

115-4 Boost Pressure (Actual)

230-1 Rail Pressure - Specified

230-2 Rail Pressure - Actual


Boost / Timing:

001-1 Engine Speed

003-4 ignition Timing

020-1 Cylinder Ignition Angle Delay (cyl 1)

020-2 Cylinder Ignition Angle Delay (cyl 2)

020-3 Cylinder Ignition Angle Delay (cyl 3)

020-4 Cylinder Ignition Angle Delay (cyl 4)

031-1 Lambda, Current Value

054-3 Accelerator Pedal Position

101-3 Injection Timing (Median)

114-3 Engine Load (actual)

115-4 Boost Pressure (Actual)

230-2 Rail Pressure - Actual


MAF / Load:

001-1 Engine Speed

003-2 Intake Air Mass

031-1 Lambda, Current Value

054-3 Accelerator Pedal Position

054-4 Throttle Plate Angle

101-3 Injection Timing (Median)

103-1 Current Fuel Pressure

114-1 Engine Load (specified)

114-3 Engine Load (actual)

115-3 Boost Pressure (Specified)

115-4 Boost Pressure (Actual)

230-2 Rail Pressure - Actual


Misfire:

001-1 Engine Speed

003-2 Intake Air Mass

015-1 Misfire Cyl 1

015-2 Misfire Cyl 2

015-3 Misfire Cyl 3

016-1 Misfire Cyl 4

054-3 Accelerator Pedal Position

054-4 Throttle Plate Angle

101-3 Injection Timing (Median)

115-3 Boost Pressure (Specified)

115-4 Boost Pressure (Actual)

230-2 Rail Pressure - Actual


Boost / Timing:

003-1 Engine Speed

003-2 Intake Air Mass

003-3 Throttle Angle

003-4 Ignition Timing

020-1 Cylinder Ignition Angle Delay (cyl 1)

020-2 Cylinder Ignition Angle Delay (cyl 2)

020-3 Cylinder Ignition Angle Delay (cyl 3)

020-4 Cylinder Ignition Angle Delay (cyl 4)

031-1 Lambda, Current Value

114-4 N75 Duty Cycle

115-3 Boost Pressure (Specified)

115-4 Boost Pressure (Actual)


The following are general logging blocks found on the 3.0 TFSI (Simos 8.4):


22 Throttle Position

24 Accelerator Position  

33 Long Term Fuel Trim Bank 1  

34 Long Term Fuel Trim Bank 2  

35 Engine SpeedRedline = 7,200 RPMRedline = 7,200 RPM

128 Ambient Pressure  

292 Timing Retard Cyl 1  

293 Timing Retard Cyl 2  

294 Timing Retard Cyl 3  

295 Timing Retard Cyl 4  

296 Timing Retard Cyl 5  

297 Timing Retard Cyl 6  

298 Ignition Angle  

421 Mass Air Flow

436 Boost Pressure (absolute)

632 Intake Air Temperature  

702 Boost Control Valve Angle


The following Examples are for Naturally Aspirated MED9 / MED17 ECUs (2.5L, 3.2L, 3.6L etc)


General:

001-1 Engine Speed

001-2 Coolant Temp

003-2 Intake Air Mass

003-4 Ignition Timing

011-3 Intake Air Temp

031-1 Lambda, Current Value

031-2 Lambda, Specified Value

054-3 Accelerator Pedal Position

054-4 Throttle Plate Angle

101-3 Injection Timing (Median)

114-1 Engine Load (specified)

114-3 Engine Load (actual)


Timing:

001-1 Engine Speed

003-4 Ignition Timing

020-1 Cylinder Ignition Angle Delay (cyl 1)

020-2 Cylinder Ignition Angle Delay (cyl 2)

020-3 Cylinder Ignition Angle Delay (cyl 3)

020-4 Cylinder Ignition Angle Delay (cyl 4)

031-1 Lambda, Current Value

031-2 Lambda, Specified Value

054-3 Accelerator Pedal Position

112-4 Median Exhaust Temp

114-1 Engine Load (specified)

114-3 Engine Load (actual)